The HEDDphone was tested and reviewed at the premises of newly-launched South African online Head-Fi company, Lumous Audio. I was not incentivised to write this review, and the opinions expressed are entirely my own.


Introduction

I’ve been wandering around the cavernous headphone rabbit hole for more than four years now, experiencing many of the fascinating creations it has to offer, to the point where there’s little that genuinely surprises me now when I listen to it.

That changed recently when I finally got to hear for myself one of the most talked about headphones in recent history, the HEDDphone. Simply named after its founding company, Berlin-based Heinz Electrodynamic Design (HEDD), the HEDDphone is the world’s first headphone to feature a full-range AMT (Air Motion Transformer) driver, an audio transducer technology invented by Oskar Heil and perfected by German physicist Klaus Heinz (yes, the self-same Heinz in HEDD).

Without getting into details that are probably better covered elsewhere, AMT technology is not new, and in fact has been used in speakers and some headphones for years. Until the HEDDphone, however, AMT was primarily used for tweeter designs, popularised by the famous ribbon tweeters in Adam Audio studio monitors.

As a tweeter technology, AMT’s claim to fame is speed and precision. Made from an ultra-thin mylar ribbon and suspended between two dipole magnets, the drivers have a surface area up to 80% larger yet significantly lighter than traditional dynamic driver speaker designs, and so can move air much quicker when activated by an electrical signal.

HEDD uses what it calls VVT (Variable Velocity Transform) technology to vary the depth and geometry of the driver, thus expanding the narrower frequency range of AMT tweeters to produce full range (10Hz – 40kHz) sound.

For every clever technology, however, there’s always a downside. In the case of HEDD’s full-range drivers, the downside is size – and weight. Each driver is hand-assembled and placed into a protective box made of (what appears to be) stainless steel, not only to protect the sensitive diaphragm, but also allow for the correct sizing needed to produce the desired sound quality in headphone format.

The driver canisters are then suspended inside the solidly-built leather-padded metal shell of the HEDDphone, resulting in what has to be one of the largest and heaviest headphones on the market today. It’s worth watching this video to get a good idea of what the process entails (trust me, it’s fascinating).


This is not a headphone for sissies; a few gym sessions and some serious neck muscle toning is strongly advised prior to tackling this beast. Jokes aside, the HEDDphone has actually been very cleverly designed to balance most of the weight strategically around head and shoulders. The thickly-padded headband is kinked right in the middle, preventing the painful hotspots typically associated with heavier headphones like Audeze’s LCD series (although that problem has since been alleviated with Audeze’s new suspension strap design).

A suspension strap would actually be a useful add-on to the HEDDphone, and I’ve already seen photos of users retrofitting their own straps to help lighten the load. Most of the weight, however, is literally cushioned by the giant pads that not only serve to soften the clamp of the headphone against your face, but also distance your ears from the gravitational pull of the giant magnets inside each of the cups (that last part about the magnet isn’t strictly true of course, but it was fun to write anyway).

Truth be told, I had a harder time wearing an unsuspended LCD-3, and even a Focal Elear, than I did with the HEDDphone. Make no mistake, this is not a portable headphone, and I wouldn’t even suggest walking around with it. But lying back in a comfortable recliner, you’ll soon forget you’re wearing helmet-sized headgear, and just get on with the business of loving your music.

I’ll link to other reviews at the end of this article that dive deeper into the packaging and unboxing experience, in case any of that interests you. If, like me, you’re more interested in what the HEDDphone can do, and how it compares to other headphones in and around its not-unsubstantial price point, read on.


Sound impressions

Let me not keep you in suspense through the next thousand words of flowery sound descriptions: simply put, the HEDDphone is the single best headphone experience I’ve had in all my time using, testing and reviewing headphones. It conveys music in such a powerful, immediate yet delicate and refined way, that it’s as close to a full-size high-end speaker setup I’ve heard without using actual speakers.

I tested the HEDDphone using a wide variety of tracks from my playlist, from my staple female singer-songwrites, to modern and classic pop, jazz, classical, EDM, and some light rock. If you want impressions of what it sounds like with heavier stuff than, say, Def Leppard, I’m the wrong guy to ask, but I can only assume that its mastery over just about everything else I threw at it bodes well for a clean sweep of genres.

Tonally the HEDDphone is all about clarity. The first thing I noticed is how crystal clear every nuance of sound seemed to be, emanating from an ink black background and an almost infinitely deep stage. This is probably unsurprising given that AMT drivers are best known for their ultracrisp treble quality, but even so, the clarity, air and sheer detail delivery was surprising.

As a big fan of the HD800 I’ve heard my fair share of bright-leaning treble, but here was something different. It had brightness, yes, but it was brightness without hardness, so the details, while there, were never forced on me.

Listening to Gheorghe Zamfir’s The Lonely Shepherd, I could almost hear the air moving up from his lungs into the panpipes. The subtle guitars in left channel were so clear, so perfectly separated from the pipes, I could almost see them being plucked. Delicate sounds were being played on different layers and levels, an impossible feat without impeccable lower and upper treble control and definition.

The HEDDphone’s treble response was also my first clue that, great as it can be, it very much depends on proper amplification. Whereas the piano in the intro to Daft Punk’s Within was very tight, it was also brighter and thinner in tone before I switched over from a built-in headphone amplifier to a dedicated high-powered amp. Only then did this track go from clinical and edgy to a more refined presentation.

The same can be said of HEDDphone’s bass response. Whereas I initially felt the bass was slightly lacking on some of my tracks – the kick drums in Brandi Carlile’s masterful The Story didn’t have quite the kick I know them to have – I later discovered that amplification quality is crucial if you expect the HEDDphone to perform at its peak.

Once properly amped, the bass hits hard and true, and although I wouldn’t rec the HEDDphone to bassheads, there was more than enough quantity for this reformed basshead, and the quality was nothing short of sublime. I was even greeted with impressive sub bass rumble in the intro to Dirk Elhert’s Elements, and the kick drums to Def Leppard’s Love Bites had a punch I could feel in my cheeks, not something I’ve heard too often with open-back headphones.

Compared to Meze’s Empyrean, a hybrid planar flagship headphone that retails for a solid $1000 more than the HEDDphone, the bass is more linear, digging deeper into the sub bass without any bloating in the midbass. It’s perhaps not quite as aggressive and sustained as the brilliant bass response of Audeze’s LCD-3, but is tighter and more detailed, and notably faster to my ears.

Both Empyrean and LCD-3 tend to favour a warmer tonality, the Empyrean even more so with its bloomy midbass that veils over the fundamentals of the midrange, and while the HEDDphone isn’t strictly neutral, it’s definitely closer to a reference bass tuning than its more coloured compatriots.

Speaking of midrange, this was perhaps the star of the show for me as far as tonality is concerned. Almost every other headphone I listened to alongside the HEDDphone emphasised one or other frequency over the others, to the point of distraction. The Empyrean’s midbass and slightly rolled treble, the LCD-3’s dominant sub-bass and smoothed over upper registers, and the HD800’s aggressive treble and rolled off bass come to mind.

With the HEDDphone I didn’t feel it compromised in any one area, and whereas the midrange of the three other headphones was almost an afterthought, on the HEDDphone it was front and centre, neither recessed or too forward, and perfectly balanced with the extremities.

Vocals and instrument fundamentals were particularly natural and lifelike, not quite organic – as that would suggest a warmer tilt – but far from thin or analytical. Imogen Heap’s vocals in the spritely track Between Sheets are sweet, clean, sibilance free and ultra-realistic. I could hear every inflection in her voice, while the sense of stage and separation from the instruments allowed me to almost walk around the song (yet also sit back and take it all in).

Holly Throsby’s sweet vocals in What Do You Say played off perfectly with Mark Kozelek’s warm, reassuring baritone on the same track, resulting in an incredibly palpable presentation that felt as if there was nothing between the singers and my ears. Switching pace, the vocal trance of Fragma’s You Are Alive was smooth and absolutely sibilant free, nicely separated from the effects dancing around the vocals, with echoes and reverbs creating a massive sense of space.


Technically the HEDDphone is easily at flagship level, and I’ll go as far as say this is a new standard for headphones in this price range. Neither the LCD-3, at around the same price point, or the Empyrean costing significantly more, can compete with the HEDDphone for sheer technical acuity. The only headphone I’ve heard that goes toe-to-toe technically is the HD800, although I much prefer the HEDDphone’s tonality to the HD800 (sans SDR and EQ).

Stage in a headphone is a controversial topic, especially compared to live sound and speakers, but the HEDDphone presents one of the biggest stages I’ve heard in a headphone to date. It’s not quite as wide as the HD800, but significantly deeper and taller, and gives a better sense of size to the music.

Made in Heights’ Hors D’Oeuvre is a track I often use to test space, and indeed I heard sounds appearing out of a jet-black background that gave this track a natural sense of space, with endless decays. Lily Kershaw’s Always and Forever was more spacious yet also more cohesive than I’d heard it before, with minutae details floating around the 3D space created by the HEDDphone.

This track also exemplifies the inch-perfect imaging this headphone is capable of, so when Lily’s vocals split into three at the two-minute mark, I could almost see where each ‘voice’ was standing in the space relative to the centre image.

But of all the technical highlights, detail retrieval has to be the most impressive trait of this headphone. Every single subtle sound can be heard exactly where it’s been placed in the mix, and throughout my audition I never stopped delighting at how the details seemed to appear so vividly, as if from nowhere and everywhere at the same time.


Considerations

Be warned, all this quality doesn’t come cheap, and doesn’t come easy. I already mentioned how heavy the monstrous frame of the HEDDphone can feel on your head, and this bears repeating. You’ll want a quiet, comfortable, well supported place to rest your body and head before embarking on a proper listening session.

You’ll also need power – and plenty of it – to drive the HEDDphone to its full potential. Voltage isn’t really an issue, and it’s not difficult to get the HEDDphone to loud enough volume levels. But without enough juice, enough current, you’re going to hear a steep dropoff in dynamic range, and wonder where all the sub bass has suddenly disappeared.

This is not a headphone you’re going to be happy connecting to a basic portable source – definitely not a phone, and not a midrange DAP either. You’ll want something with muscle, like a HiBy R8 or iBasso DX300, or better yet a powerful portable amp like Cayin’s C9, if you’re even thinking of taking this headphone off the desktop.

As for desktop power, only when I had the HEDDphone connected to an Eddie Current Black Widow did I get a proper understanding of what this headphone can do, technically and tonally (and if anyone knows the story of this rare and unique solid state amp you’ll know how special it sounds). That’s not to say you have to splash the same money on amping the HEDDphone as the headphone itself, but doing so will give you a far better return on your investment.


Closing thoughts

Listening to HEDDphone was a wild ride for me, especially since I’ve switched my listening almost entirely away from full size desktop headphones to IEMs. It was a reacquaintance of sorts with the type of sound that set me on my head-fi journey more than four years ago, and in many ways, is a reaffirmation of just how incredibly rewarding the sound of a truly great headphone can be.

For all its wizardry and world-first technology, the HEDDphone at its core is all about recreating music exactly as it was recorded, with very little in the way of ‘gear’ in the way. It’s not a headphone that sets out to colour the music, or to wow you with unconventional staging, gratuitous bass or scalpel-like detail. It hits the highest possible level of fidelity almost from the off, and then maintains it throughout your listen, track after track.

Even though I consider the HEDDphone to be close to a so-called ‘reference’ tuning, it still maintains a sense of musicality that’s fun to listen to and is about as far from dry or clinical as you can get in this hobby. Yes, it asks for some skin (or rather, muscle) in return, and demands as much power as your wallet can muster, but it will reward you handsomely if you give it what it wants.

In closing, I’ll leave you with this: the HEDDphone is a headphone for the headphone connoisseur. It sacrifices some of the comfort of an Empyrean, the brute strength of an LCD-3, and the clinical precision of an HD800 to create a sound as close as possible to life itself. It gives you everything without forcing anything, and in doing so, allows you to lose yourself in the music in the best possible way.

Without question the HEDDphone gets my highest recommendation, and represents the best value of any high-end headphone I have personally has the pleasure of hearing.

The HEDDphone is available in South Africa from Lumous Audio. More information available here.


Further reading

This review didn’t cover several aspects that some of you may be interested in, like packaging, accessories and comparisons to different headphones. Feel free to peruse some of the other excellent reviews of this headphone available online, including:

• Headfonics
• Headfonia
• Headphones.com
• Headphone Check

I would like to thank @Andykong for providing a review sample of the RU7 and additional technical information as required. This review is an extract from the The Superdongles feature in The Headphone List.


I have a real soft spot for Cayin, even though I haven’t owned a Cayin music player since my very first DAP, the Cayin N3, several years ago now. I briefly flirted with Cayin’s RU6, given my preference for ‘analogue’ R2R DACs, but found it redundant alongside the more powerful R2R DAPs I used at the time (and still do), nor the most resolving dongle I’d heard with my IEMs.

When Cayin first introduced its N7 DAP earlier this year, I was intrigued by the inclusion of a discrete 1-bit (DSD) DAC in a portable player, a first of its kind. Well, Cayin has done it again, only this time shrinking its 1-bit DAC design even further for the dongle format.

Cayin’s RU7 ($290 at Musicteck) features the world’s first discrete 1-bit DAC in dongle format, following closely on the company first 1-bit DAC-in-a-DAP in the N7. It’s a sign of the times that you can now get native DSD audio up-sampling from a low-power portable dongle the size of a matchbox – a feature that was previously the preserve of some serious desktop computing hardware. Not only that, the RU7 isn’t far behind the N7 when it comes to driving power, especially with IEMs, despite the $1,700 price difference between the two.

It has other interesting features too, like a dedicated, albeit basic, line out mode, and an All-To-DSD engine that I’ve only seen in seriously expensive players before now.


Packaging and accessories

RU7 ships in an small, understated box with a matte black satin finish and a glossy silkscreened image of the dongle from two different angles. Inside the box you’ll find the dongle in a custom foam tray, and separate tray with a USB-C to C cable and USB-C to A adapter.

There is no USB-C to Lightning adapter or cable included, Cayin opting to sell its $20 CS-L2C cable separately for some reason. Cayin does include a protective green leather case as standard, however, along with two matching leather stick-on magnetic patches to connect the dongle to a smart device in case you want to stack them.

Design and use

RU7 has a ‘conventionally’ rectangular design, coated in a silky-smooth matte-black aluminium finish with a glossy glass top. A small OLED screen is built into the glass panel, offset to the left of the player rather than centred in the frame.

There are three slightly raised buttons on the topmost long side of the dongle, two volume toggles and a menu/function button. Outputs include 3.5mm single-ended and 4.4mm balanced headphone ports, which double as true line-out ports for connecting RU7 to external amps without double amping.

One usability issue I have with the input buttons is that they’re flush with the case, and although the case is slightly indented around the buttons, I often end up lowering o raising the volume when I want to do the opposite, or accidentally changing the volume when I want to change settings.



Specs

• DAC: 1-bit discrete resistor fully-balanced 4-channel DAC
• Volume control: discrete resistor 100-step linear volume control
• FPGA: No
• SNR: 114dB (3.5mm) 112dB (4.4mm)
• Power output: 160mW (3.5mm) 400mW (4.4mm)
• THD+N (32-ohm): 0.006% (3.5mm) 0.008% (4.4mm)
• Dynamic range: 115dB
• Screen: 0.91-inch OLED
• Audio formats (PCM): 16/24/32-bit 44.1-384KHz
• Audio formats (DSD): DSD64-256
• Dimensions: 66mm x 24mm x 12mm
• Weight: 25g

Settings

• Gain: choose between low and high gain, for sensitive to less sensitive loads.
• All to DSD: choose between up-sampling PCM audio to DSD64, 128 and 256.
• Output: choose between PO (headphones out) and LO (line out).
• Backlight: choose between permanently on, to auto off in 10-second increments between 10 and 60 seconds.

Notable features

World’s first dongle-based 1-bit discrete resistor DAC. Made up of 128 pieces of 0.1% 25ppm high precision thin film resistors, the custom-made 1-bit DSD DAC features an All-To-DSD engine that up-samples incoming PCM signals to DSD64, DSD128 or DSD256. The higher the setting, the more precise the conversion with higher resolution. The up-sampling level also has a perceptible effect on tonality.

Parallel dual phone amplifiers. Cayin has implemented dual parallel amplifiers in the RU7, boosting amplification current by as much as 80% from the RU6. They’ve done this without significantly increasing the noise floor of the amplifiers, resulting in a near-silent noise floor with all but the most sensitive IEMs.

Shared line out ports. It’s rare to find a line out function in a dongle because of the limitations on the hardware needed to provide a separate line out circuit. Cayin circumvented this limitation by folding line out functionality with the headphone ports.

This does limit line out quality and output levels – 1.2V for single-ended and 2.4V for balanced (compared to typical 2V and 4V outputs in dedicated DAP line outs), but it’s apparently a user-requested feature and so Cayin made it happen.

Be warned – selecting line out is not automated, and the dongle won’t switch back to headphone mode after a line out session, so be careful when you use this feature to switch back to PO, especially when using sensitive IEMs.

Discrete digital volume array. RU7 uses three banks of resistors and switching relays to provide 100 steps of precise volume increments.

Separate digital and analogue circuits. The digital and analogue sections of the RU7 are split into two separate PCBs, shielding the analogue amplification signal from digital clock and DSP noise.



Sound impressions
Tonally, RU7 has a rich, slightly warm, and subtly coloured tonality that emphasises some frequencies over others. Bass gets a moderate bump, more midbass than sub, which makes certain instruments and lower midrange vocals sound fuller and warmer than they would from a neutral source.

Midrange is fairly linear, though lower mids ‘benefit’ from the thicker bass density, if that’s your preference. That’s not to say any part of the midrange is veiled; on the contrary, I find RU7 to have an excellent degree of clarity through the mids, without any veil whatsoever, but the midrange notes are sweeter and sound quite organic, especially when up-sampling to DSD64.

Treble also gains a subtle boost to my ears. It’s not peaky, and I definitely wouldn’t call RU7 a ‘bright sounding’ dongle, but there’s plenty of energy here when the music calls for it. Overall, I find RU7’s tonality to be quite ‘musical’, which is to say warm of neutral with a natural, organic and full sound through the midrange, and enough shine in the highs to sparkle even when the bass is pumping.


Despite its obvious musicality, RU7 delivers excellent and occasionally outstanding technical performance. I’m hearing a decently wide stage with most IEMs, not quite as wide as I do with more powerful and expensive sources, but I don’t feel staging is compromised in any way either.

Other staging elements, like imaging, separation and layering, are all very good, and consistent with the highly technical levels achieved by the higher-end IEMs I used for testing. I did come across the odd track the sounds a touch more congested than I’d like during very complex passages, but that’s to be expected given the limitations of the format, and it’s only apparent in comparison to larger sources.

I thought for sure that noise would be a bigger problem than it is; I’m yet to hit any significant noise floor with any of my IEMs, even when turned up loud, and even with super sensitive IEMs where noise would sometimes be an issue. This is even more impressive given RU7’s powerful and very dynamic sound, that would normally show up any issues with signal noise, but to my ears, there is none.

Overall, I feel RU7’s ‘superpower’ is its ability to deliver such a rich, coherent and lively sound with a high degree of technical polish. From memory (and copious notes) this alone sets it apart from its predecessor, the RU6, and is possibly reflective of the technical advantage of its 1-bit DAC compared to the latter’s R2R derivative.



Select pairings

FiR Audio Rn6. RU7 warms up this already warm-of-neutral ‘reference’ IEM a touch, making it sound fuller, wetter, more cohesive but slightly less resolving. It’s musical but not muddy, with a punchy bass and vocals I can usually describe as earthy. Stage can is wide on some tracks, but with busier music it can get a little congested. An excellent pairing, and easily driven, with low-thirds volume in low gain.

FatFreq Maestro SE. With RU7, MSE comes into its own, offering up a warm, pleasantly even tonality with standout bass when called for. RU7’s slight midbass bump works well with MSE’s rather linear midbass tuning. It also works nicely with MSE’s neutral midrange, adding a touch of warmth and weight to vocals, though female vocals are still quite airy and occasionally wispy. Treble is nicely extended, and not too elevated, but sparkles and shines where it needs to without getting in the way or taking over the performance. Another excellent pairing, with a comfortable listening volume at 55/100 in high gain – not bad considering how difficult MSE is to drive.



HiBy Zeta. With RU7, Zeta takes full advantage of the slight bass lift to deliver a bold presentation that somehow doesn’t bloom or spill over into the lower midrange. While vocals (and the midrange in general) isn’t as resolving as it is with MSE or Rn6, it holds its own with just enough detail to satisfy and never too much to fatigue. I like how RU7 controls Zeta’s occasional upper midrange peak, and so is never shouty or sibilant, even with poorly recorded material. Easily driven at low volume in low gain, this is another excellent pairing, and shows off RU7’s versatility with different IEM tonalities and sensitivity.

Sony IER-Z1R. With RU7, Z1R has more midbass heft, and more bass in general. Vocals are well separated, and treble is clean and distinct, giving the sound a deeper U tonality. If you like your Z1R warmed up, RU7 will do that, though the famous Z1R stage will sound slightly more compressed and not quite as deep. Another IEM that loves power, and RU7 delivers impressively at 45/100 in high gain.



Compared to L&P W4

RU7 is notably warmer-sounding than the more neutral W4. RU7 bumps the midbass region ever so slightly, thickening the note weight of the lower frequencies. W4, by comparison, is more sub-bass focused, with a tighter bass punch and not quite as much weight or decay in the midbass notes.



Increasing the DSD rate on RU7 has the effect of stretching out the lower frequencies, or at least relative to the increase in midrange and treble detail, but the bass never becomes a tight as with W4. Even though bass is still nicely controlled on RU7, it’s also ‘bigger sounding’ than W4, mostly due to this subtle bass lift.

I hear similar differences in the midrange of these two dongles. W4 shoots for clarity and transparency, with a neutral and fairly linear midrange that’s more revealing, while RU7 mids are a touch denser and more euphonic. The lower the DSD sampling rate, the ‘wetter’ the RU7 mids become, although at no point do they get as warm and full as the midrange of a typical R2R DAC like RU6 or HiBy’s RS6.

RU7’s lower midrange sounds slightly fuller to me, but also a touch more recessed compared to W4, whereas the upper mids are mostly on par between the two. That’s not to say W4’s mids are thin. Both dongles dig deep into the musical information in the midrange, and neither come close to sounding overly analytical. RU7 leans slightly more musical than W4 in the midrange, however, but W4 in turn sounds more accurate, with a lifelike, natural timbre to instruments and vocals.

The upper frequencies of both dongles are also quite linear, without any notable peaks or dips, and excellent extension. I’d hazard a guess that RU7’s treble is ever so slightly lifted compared to W4’s crisp and neutral treble response, but it would be just that, a guess.

Combined with the bass lift, slight lower midrange recession and subsequent treble rise, you’d be forgiven for thinking RU7 has a V-shaped tonality, but it’s much closer to a gentle U. W4, in contrast, is even flatter by comparison, about as close to true neutral without ever crossing into stale, cool or analytical territory. Both dongles are naturally musical, but RU7 is musical with a warmer, fuller tilt.



The technical level of both these dongles is nothing short of impressive. I’d be hard pressed to pick out the difference between either dongle and a really good mid-to-upper tier DAP based on technical performance alone.

That said, and since I won’t be comparing these dongles directly to actual DAPs other than in passing subjective comments, there is a limit to how technically-accomplished and refined you’ll hear them yourself, especially if your weapon of choice is a higher-end DAP or desktop system.

The stage size of both dongles is very similar; neither dongle projects the largest stage I’ve ever heard, but neither is staging too intimate. Width, height and depth are just about even, with W4 maybe edging RU7 in depth and RU7 sounding a hair wider. Both are what I consider natural, projecting sound ever so slightly out of head with my largest-stage IEMs, but not quite as holographically as I know them to be capable of.

Where W4 does take the lead is in separation and layering, aided perhaps by its mildly leaner tonality. Sounds emanate more distinctly from the blackness of the background with the W4, and are also more spaced out from each other. Imaging is excellent with both, neither coming off as too diffused, especially in light of their average stage size.



Speaking of background, both dongles are essentially noise-free. RU7’s thicker notes and closer spacing might give the impression of a less inky backdrop, but I don’t think that has anything to do with noise. Regardless, W4 does sound cleaner. It also sounds more detailed, and while RU7 is at least as resolving as some higher-end DAPs and desktops with the same IEMs, W4 is even more so.

Dynamically, RU7 is the more exciting of the two. That said, depending on the setting, RU7 can also lean more relaxed (DSD64), and switching W4 to Tone 01 has a similar effect on the sound.

Overall, both RU7 and W4 have set a new benchmark for technical performance for dongles, at least of the many dongles I’ve heard. Both outclass their predecessors, for example, sounding cleaner, more precise, less noisy, and more resolving. Where they differ more is tonally, which in turn affects the perception of the subtle intangible technical differences I’m hearing.

The only cap on performance is the cap imposed by the physical size of these devices. Sadly, not even the most ingenious DAC designs or amplification circuits can defy the laws of physics, and as such expecting dongles – even these Superdongles – to match and exceed the performance of larger, more complex, and more computationally-powerful devices is fanciful. It’s not about price, it’s about size.

But, on their own terms, the sound quality they have already attained is about as good as we’re going to get in this format with current technology.



Closing thoughts

Cayin’s RU7 continues the company’s hot streak of breaking new ground in DAC design for the dongle format, and I won’t be the first to say the all-new 1-bit DAC in the RU7 is even more impressive than the R2R DAC in its predecessor. Not only that, the new parallel amp design has proven itself with some of the hardest-to-drive IEMs I’ve ever used, and in doing so, RU7 is no longer hamstrung by piddly power output, the usual Achille’s Heel of most dongles.

With a smooth, rich and musical tonality, RU7 is also the most versatile dongle I've used with the selection of high-end IEMs in my collection, and is probably my pick of the new crop of 'superdongles' if I could only choose one. Highly recommended.

Introduction

I’ve been thinking about how to best write this review for a while, ever since I first experienced HiBy’s new flagship DAP towards the end of last year.

Since then, every other major Chinese DAP manufacturer has been playing catch-up with HiBy, and today the market for high-end ($1000-plus) portable music players is already getting crowded.

Marketing 101 stipulates that, given a crowded market, the success of a premium product is directly related to how different it is, what unique features it offers, or even what it looks like, so that the relatively small pool of potential buyers sits up and takes notice, singles it out from the crowd, so to speak.

While the R8 does have some distinguishing features that make it different to the others, its biggest differentiator – a 4G sim card, the first such feature in a DAP of any description – isn’t actually a feature at all, given its not available outside China and a small handful of Asian countries.

Of the features that do count, for western users anyway, at the time of its launch it was the first high-end DAP to incorporate the double-whammy of a relatively modern processor/system-on-chip (Snapdragon 660) with a relatively modern Android platform (version 9), making it the fastest and most up-to-date Android DAP on the market.

But perhaps I’m looking at it the wrong way, and it’s not just one feature that makes the R8 different to the others. Rather, it’s the combination of features that make it, in my opinion, the most complete flagship DAP available today.


A premium package

Given its launch price of $1899 (for the non-4G, all-aluminium, 64GB ‘western’ version), the R8 more than doubles the cost of HiBy’s previous flagship DAP, the R6 Pro. This puts it firmly in the upper price bracket of the DAP market, with only the likes of Lotoo, Sony, Luxury Precision and Astell & Kern offering higher-priced models, a list which includes exactly none of HiBy’s traditional mainstream Chinese competitors.

Of course, this pricing suggests the R8 has a seriously ramped-up spec, which it does (see the next section for a breakdown of the tech specs), but more importantly, HiBy made every effort to position the R8 as a premiumpackage. This is not just another player update, but rather the foundation of a high-end portable audio system.

Most modern DAPs, especially expensive DAPs like the R8, are well presented in quality packaging. Some come with multi-layered carboard boxes, others with wood cases and leather accessory holders. Most come with decent leather protective cases and even screen protectors.

The R8 is a step-up from all that. Inside the sizeable but otherwise nondescript black box is a well-made, genuine leather, classically-styled briefcase, complete with belt buckles and carry handle. That’s right, briefcase. Why would you want a briefcase for a portable music player you’re just going to slip in your pocket or throw in your backpack for the train ride to work? Because you’re not going to do that with the R8, or at least, HiBy is using design cues to suggest that’s not what the R8 is all about.


Opening the case reveals the player inside a custom cutout tray. Alongside the player, an aluminium placard with ‘HiBy R8’ etched into it tells you what you just bought, in case you didn’t know. The only other visible accessory is a pull tab on the pre-applied screen protector on the R8 itself (a very nice touch, often missed by companies wanting to cut costs). Turn the player over and you’ll find a second pre-applied screen protector on the glass-backed casing, even though the casing is made of Corning Gorilla Glass and should be fairly impervious to damage anyway. I do wish the screen protectors were glass and not film, but that’s a minor gripe.

Lifting the top tray (using tabs on either side of the tray) reveals a second tray with a similar player cutout, only this time instead of the player it houses a genuine leather case for the R8. If you were one of the first 100 buyers, you’ll be greeted with an exclusive limited edition Dignis case (which, judging by Dignis case prices for other premium players, is valued at around $200). If you buy an R8 today the case will be HiBy’s own original leather case, with a different design, colour and finish, but still attractive and well-made.

Alongside the case, two circular cutouts hold the R8’s connector cables: a high-quality HiBy-branded USB-C to USB-C cable for charging and data transfer, and a HiBy-branded USB-C to coaxial digital cable for connecting the R8 to an external DAC.


But wait, there’s more. HiBy included a third tray (in a separate box), which features covered cutouts to hold spare tips, connectors or loose IEMs, four small cutouts for extra MicroSD cards, and two more round cutouts (similar to the cable cutouts) to hold two sets of IEMs attached to their cables.

In other words, this briefcase is not just a fancy presentation gimmick, but rather a premium storage and carry case for your (possibly entire) portable audio system.

A premium player

At first glance, the R8 exudes quality. Made from a solid block of CNC-milled aluminium, it is not small or light, measuring 143 x 81 x 20mm and weighing in at a pocket-busting 466g with the Dignis case. That’s significantly bulkier and heavier than the stainless steel R6 Pro, which itself was quite a hefty, albeit more pocketable DAP.

I therefore wouldn’t call the R8 easily portable, although strictly speaking it’s still portable rather than transportable. It’s not a desktop-replacement DAP (like iBasso’s DX220 MAX or Sony gargantuan DMP-Z1), but given its size and power, can very easily do double-duty as one.

The design of the DAP itself is a departure from HiBy’s previously rounded aesthetic, being more angular and aggressive (or ‘masculine’ as HiBy calls it). That said it’s not nearly as angular or sharp-edged as Astell & Kern’s obtusely-shaped DAPs, and its slightly rounded edges mean it can be used comfortably without a case.

This is not a random design choice, and is grounded in how the R8 functions ergonomically. For example. The four push-buttons on the right side of the player (power on/off, previous track, play/pause, and next track) use the angled sides of the player to prevent you from accidentally clicking them while making it easy to find and click them by feel.

Between the buttons, a slot-like LED shows the various states of the player, whether it’s charging, or which bitrate it’s playing (the LED can be turned off in settings if you prefer not to use it). HiBy has also moved away from push buttons for volume, using a Lotoo-like knurled alumimium volume dial on the top of the player, protected from accidental activation by the angled edges of the player. The volume dial isn’t very sensitive, and takes a touch or two to activate, which I believe is a design choice. I like it, but some may prefer a more sensitive dial.

On the left side of the player, a single sim-tray opens up to reveal a MicroSD slot, which is hidden away when the player is in its case. I personally prefer the sim-tray design, especially since I hardly ever swap out my SD card (more on how I use and manage my music library with the R8 later). The bottom of the player is where you’ll find all the active ports: two headphone ports (3.5mm single-ended and 4.4mm balanced), two dedicated line-out ports (SE and balanced), and a USB-C 3.1 slot for charging, data transfer and external DAC use.

The back of the player, despite being glass covered, is also its heat diffuser, and can get fairly warm when playing music, video, streaming, or driving power-thirsty headphones. That said, the R8 doesn’t get uncomfortably warm, even when charging, and both leather case designs (Dignis and HiBy) include an alumimium heat shield that allows for good ventilation and heat dispersion when the player is used screen-up, as it normally would be.

Which leaves the entire front face of the player as the screen, an outstanding 5.5”, 1080P IPS retina touchscreen at that. No, it’s not going to compete with the ultra-punchy OLED screens used in modern high-end smartphones, but it’s a very impressive screen befitting a premium DAP, with good contrast, excellent touch sensitivity, natural and accurate colours at all viewing angles, and an almost edge-to-edge display that’s easily visible in bright light and daylight.


If the exterior of the R8 is heftily-impressive, what’s on the inside is even more so. The spec sheet of the R8 includes:

• Dual AKM AK4497EQ DACs with support for native DSD512 and 32bit / 768kHz PCM
• Snapdragon 660 octa core 14nm LPP process SoC with CPU frequency up to 2.2GHz
• HiBy OS, a highly-customised version of Android 9 (Pie) complete with built-in Google Play Store support, Direct Transport Architecture (that allows for native hi-res playback), and 16X native MQA rendering support
• Qualcomm 8x Kryo 260, Adreno 512 GPU, 4GB RAM, 64GB ROM and up to 2TB SD storage
• Custom high-density 38Wh ATL 10,000mA battery for up to 13 hours playback with QC 4.0 support
• Four independent power supply circuits for digital, DAC, preamp and amplification
• Up to 1088mW output power into 32ohms from the balanced headphone port
• Turbo mode for even more driving power (up to 16W) for over-ear and less-sensitive IEMs
• Four ELNA SILMIC II audio capacitors and exclusive HiBy-designed OP02 opamps
• 10 tantalum gold-plated capacitors, 18 high ripple-suppression-ratio LDO regulators, and 35 Panasonic Hi-Polymer POSCAPs (I have no idea what all this means but it sounds impressive)
• Dual 45.1584MHz and 49.152MHz oscillators with femtosecond precision, controlled by a dedicated, custom FPGA chip
• 2.4/5GHz dual band WiFi, Bluetooth 5.0, two-way Bluetooth (transmit and receive), including HiBy’s own UAT protocol, LDAC and AptX HD

Without getting too technical about the already technical spec list above, it’s fair to say that, even at a glance, the R8 packs a seriously premium array of high-end components (including the largest battery of any modern DAP) which sets it apart from budget players that primarily use off-the-shelf parts to keep costs low. That doesn’t automatically mean it will sound or perform as well as it should on paper, but at least you know you’re not just buying a packet of chips in cuisine clothing.

A premium experience

Package, specs and smoking good looks (in the eye of this beholder) aside, this is the part of the review where the rubber meets the road, so to speak. I’ve broken down the in-depth analysis of the R8 into four sections: speed, software, sound quality and stability.

Depending on your own preferences, these criteria may be more or less important relative to each other, but to me, they are all equally important when it comes to creating a complete experience in a flagship DAP. No single feature is the only important factor, not for me, and not when you’re paying this much for a premium product.

A great sounding player can still deliver a poor experience if the UI or software is too slow or laggy, for example, or the software might lack certain features that you need, or the combination of software and hardware might be unstable under certain circumstances. So let’s take a closer look at each of these aspects in turn, and see how the R8 stacks up in real-world use.

Speed

When it was first announced, the headline feature of HiBy’s new flagship was the newer (relatively speaking) Snapdragon SoC, which promised to make the R8 the fastest Android DAP on the market. That promise materialised when, on its release, the R8 was indeed shown to be faster than any other Android DAP, and not by a small margin either.

There are a few ways to measure an Android device’s real world performance, one of which is AnTuTu Benchmark – a free tool you can download and run on your own device from the Google Play Store (or sideload from APKPure if your device lacks Play Store functionality).

My R8’s AnTuTu score of 188140, using the latest version of the software, can be seen in the screenshot below. To put this score in context, the R8 remains the fastest Android DAP on the market, based on the AnTuTu scores of its three closest flagship competitors (taken from published reviews, not my own measurements):

• iBasso’s DX300, with its similarly-specked SoC and 2GB more RAM, is almost a dead heat at 177936;
• FiiO’s M15, with its older Exynos SoC and even older Android 7.1 platform at 108448; and
• Shanling’s M8, which is actually newer than the R8 but sports a lethargic (by modern standards) Snapdragon 430 SoC running Android 7 at 74651.

To put these scores in context, however, the R8 is only moderately faster than my LG V30+ smartphone, which on the one hand means that it’s the first DAP I’ve used that’s finally caught up to the speed of a modern smartphone, but on the other, my idea of a modern smartphone is a 2017 LG.

That said, the R8 is still the fastest Android DAP today, which is an important consideration if you’re buying a DAP that is already behind the curve in terms of the latest Android hardware and software platforms. FiiO’s M15, for example, was the standard bearer for Android DAPs less than six months ago, yet is already showing its age, while HiBy’s new R6 2020 DAP matches the R8 in speed and software specs yet costs $1000 less, suggesting the R8’s platform is already the minimum you should expect from a modern flagship.

When it comes to speed, CPU and graphics are only one part of the equation. If you’re thinking of doing anything with your Android DAP that involves networking or the Internet, you’ll also need fast, stable Wi-Fi support.

The R8 is equipped with a dedicated dual-band 802.11ac Wi-Fi antenna. Comparing the Wi-Fi performance of my LG phone I found very little difference with the R8 – if anything, the R8 even edged out the phone when it had line of sight to my wireless mesh nodes.

I can’t say for sure how the R8 compares to the other flagships in terms of Wi-Fi speed, but this is a big step up from the previous HiBy flagship, the R6 Pro, and the combination of fast 5GHz Wi-Fi and its class-leading SoC makes the R8 every bit as capable a streamer as a modern smartphone.

Software

At this point the review is going to digress away from most of the other mainstream reviews. Instead of treading the same ground and describing the standard software configuration, apps and options out the box, I’m going to instead jump to how I’ve configured the R8 for my own use case.

This is important for two reasons: the basic configuration, while fully featured, is just that – basic. You get an optimised and customised (but otherwise intact) Android 9, all the Google Play Store and Services pre-installed (no need to sideload anything from APKs or stand on your head to register the Play Store correctly), vanilla applications (like a basic file manager, photo manager, web browser and clock), and HiBy’s own music player and media manager, HiBy Music.

The second reason is that none of these maximise the power and potential of the R8 as an open, optimised Android DAP, at least not by my definition of maximise. For example, the first thing I did on booting up the R8 for the first time was jump into settings and disable the apps I don’t need, including (shock-horror) HiBy Music. It’s not that HiBy Music is bad software, far from it, but in my experience to really make the most of the functionality of this (or any other open Android) DAP, you should install a more advanced third-party playback application, of which my pick would be USB Audio Player Pro (more on this later).

So that’s why this review is going to be a little different. I’m not going to run through the various screens and settings options for you – there are plenty of other, excellent reviews that already cover these, and I’ll reference these at the end of this review. Instead, I’ll walk you through how I’ve set up the R8, how I use various apps for everything from wireless file management to remote streaming, and even how I’ve totally changed the look and feel of the R8 to better suit my preferences.

OS and UI tweaks

Let’s start with look and feel, because otherwise you’re going to stare at my screenshots and wonder why your R8 looks so different to mine. One of the benefits of using a DAP with open Android is that you can change how you interface with it using a launcher application. My launcher of choice is Nova Launcher, available as either a free or premium (Prime) version.

Nova gives me complete control of the R8’s interface, from the apps and widgets that appear on the home screen, to the way notifications appear on the lock screen, and even how I group and arrange the apps on the player. Once installed, every single interface element is controlled from the Nova Settings app. I won’t go into great detail here, other than to say your choices are almost limitless. From the shape, size and colour of icons (I use an excellent third-party icon pack called Lines to get the minimalist look I wanted) to the app drawer, launch bar, folders and other UI elements, it’s now all under your control.

One thing I will mention here is gestures. The R8 already comes with that most useful of modern Android features, Tap to Wake, which as the name suggests allows you to double tap the screen to wake it from sleep. Ever since I first used this feature on the FiiO M11 I was hooked, and will never buy another smart device, Android or otherwise, that doesn’t have it. Strangely the R8 doesn’t include the reverse feature, Tap to Sleep, but fear not: a few clicks in Nova’s gestures options and Tap to Sleep is yours.


File management

The R8 is essentially an Android computer with fairly advanced hardware, so why not use it like you would any computer and manage you incoming and outgoing files direct from the DAP. While a basic file manager is included with the R8, you’ll really want a more advanced app if you want to take full advantage of the R8’s capabilities. My rec for a full-featured file management app is Solid Explorer, which among other things, allows me to manage my entire music library wirelessly over my home network.

Ever since installing Solid Explorer, I no longer need to remove the SD card or attach the USB cable for file transfer. Everything I need to copy to or from my music server or network can be done wirelessly from the R8. Solid Explorer gives me SMB access to my desktop Macs, workgroup access to Windows PCs, and remote access to NAS, FTP and Cloud storage, including Dropbox and other services. All of it can be done securely, and even encrypted, just as you would from any other computer.

Instead of describing how I use Solid Explorer, I’ve included a short video below that shows me accessing my main music library on a Mac mini server and copying a number of music directories to the R8’s SD card.

With fast 5Ghz Wi-Fi support and gigabit wireless mesh network at home, copying files to and from the R8 is much faster than doing so the old USB 2.0 way, and almost as fast as connecting the R8 directly with USB 3.1. I can also access and play music files remotely from Solid Explorer, but for that I use the remote playback capabilities of UAPP instead (see the ‘Music management and playback’ section below).



Streaming

Most people choose Android DAPs for their streaming capabilities, and the R8 is one of the very best in this regard. Not only does it support the highest level of hardware MQA decoding (16x) for Tidal users, it also supports bitperfect playback from hi-res streaming platforms like Qobuz and Amazon HD.

As a native Android player with built-in Play Store support, you have access to any of the major streaming apps out the box, including Tidal (which I personally use), Qobuz, Amazon HD, Spotify, Apple Music and YouTube Music, among others. If any of these apps support offline playback on Android, you’ll be able to use that feature with the R8, and even choose where to store your offline files (internal storage or SD card).

One of the benefits of using a fairly modern Android version with a fast SoC is evident from how quickly the latest streaming apps load and run on the R8, as I’ve illustrated in the video below. Tidal is not the world’s fastest app, but the experience is as smooth as seamless as it is on my smartphone, which is to say excellent. Searches are instant, and scrolling through large playlists is lag-free.

I can’t stress enough how big a difference a smooth interface makes to the overall experience. This was always a potential bottleneck with older, smaller DAPs, with their lower-resolution screens and underpowered SoCs. That’s no longer the case with the R8.



Music management and playback

I mentioned earlier that I use USB Audio Player Pro as my music management and playback app of choice. Not only is the app worth every cent, you can also use it across all your open Android devices, as long as they support Google Play.

Without going into great detail, I’ve listed the main the reasons I prefer UAPP to any other music app below:

• It supports bitperfect, native Hi-Res playback, bypassing Android’s limited audio layer and interfacing directly with the DACs in the R8.
• It supports native DSD playback on the R8, unlike some players that convert DSD to PCM.
• It’s is a very mature, very responsive and very stable application, with a clean, uncluttered, modern interface (including nifty features like background colours that match the cover art of the playing album), lock screen controls (including ambient display notifications on the R8), and refined English-accurate menu and navigation structure.
• It features superb media management, including automatic updates to the main library when adding or removing music files, metadata editing, extensive album art support regardless of file type, and finely-tuned sorting capabilities, including Album Artist that many OEM music apps still seem to lack.
• It’s fast, very fast. Everything from loading your library to playback to scrolling and database updates is superbly optimized on the R8.
• It’s versatile. UAPP integrates Tidal (with full 16x MQA support), Qobuz and YouTube Music, giving you access to your favourite streaming service with its native playback engine. It also features advanced playback controls and effects, including optional ToneBoosters professional PEQ, Crossfeed and Morphit plugins.
• It’s scalable. UAPP supports playback using external DACs, which turns the R8 into a high-end digital source for your desktop system, but also supports built-in DLNA and network music playback support, so you can access any of your local shares (including Plex libraries) directly from the UAPP interface.

Suffice it to say, UAPP helps me make the most of the R8’s audio hardware and networking features and turns it into a fully-fledged music playback and management system second-to-none. Since I also use UAPP on my smartphone, the experience is consistent regardless of which device I use to listen to music.

Other software and applications

While I have other applications installed on the R8 that can be used for music playback (including Tidal and Plex), I generally don’t venture too far away from UAPP for most of my listening. The R8 is also a very capable multimedia player, and even has auto screen rotation functionality should you want to watch movies and TV shows using Plex or YouTube the natural way.

Aside from UAPP, Plex is the only other app that requires Google Play Store support, which is why Play Store is essential to my DAP use case. While Plex isn’t perfect (I mainly use it at home for TV and movie playback), it does have one invaluable music feature: remote support. Basically, this means that when using the Plex app on the R8, I can access my entire 3TB+ music library wherever I am in the world.

Unfortunately, the Plex app doesn’t take advantage of HiBy’s DTA for bitperfect playback, downsampling all my hi-res FLACs and DSDs to 44.1 PCM, but that still beats not having access to my music library wherever I go. I do get full hi-res and DSD support, though, when I access my Plex library at home using UAPP’s built-in DLNA browser, as the video below illustrates.



Other than the main apps, the software features I use most on the R8 are built-in to HiBy OS (HiBy’s name for its optimised Android 9 platform). These include:

• MSEB: HiBy’s homebrewed take on an intelligent EQ, which on the R8 is available as a system-wide EQ for any music playback applications, including streaming apps. Developed by @Joe Bloggs, MSEB makes it easy to tweak the music to your liking with intuitive sliders that affect everything from overall temperature to bass texture, note thickness, vocals and sibilance, without requiring a PhD in EQ theory.
• Instant screenshots: pressing the power button once brings up a menu with one-click screenshot control, making it easy for me to take screenshots for this review.
• 180-degree screen rotation: a new feature included with the latest firmware, this is more useful than you’d think, especially if you want to pocket the R8 and have the headphone ports facing up rather than down. One click from the quick access menu and you can flip the R8 for the road.

While it technically can do much more software-wise, from Telegram and Discord chatting to online shopping and even fitness tracking, I use the R8 exclusively as the premium music player it was designed to be, but with all the supporting services and remote access capabilities I can only get from a fast, connected Android device.

Sound quality

If you jumped straight to this section from the intro, I encourage you to go back and read everything that came before if you really want to get a feel for what the R8 can really do. If all you care about is sound quality, you might be buying features with the R8 you’ll never need or use.

That said, the R8 wouldn’t be getting my rec if I didn’t think it lived up to its primary purpose as a premium music player, so I’ll get right to the point. If you want flagship-level sound quality in a portable platform, the R8 delivers.

Once again, unlike mainstream reviews, I’m not going to directly compare the R8 with other flagship players. I’ll make some reference to other DAPs I’ve personally used or owned, but I don’t have any with me to check like-for-like playback qualities. For that I refer you to some excellent reviews below, the best and most comprehensive of which is Alex’s (@twister6) industry-benchmark review, complete with detailed comparisons to other DAPs.

An important note at this juncture

While I’ve become a lot more appreciative of the role a high-end source like the R8 plays in the sound quality chain, describing the sound of a source is like describing the colour of water. What you’re hearing is first, foremost and mainly determined by whatever you have plugged in to the DAP, not as much the DAP itself.

Just like water reflects the colour of the sky, so any good DAP should primarily reflect the sound of your IEMs (or headphones). Yes, it will influence what you hear, depending on how well the DAC and amp have been implemented, but in my opinion, just like crystal clear water, a great DAP gives your IEMs the best possible foundation – clean power, low distortion and low noise – and lets them do what they do best while getting out of the way.

I used a variety of IEMs with the R8 over the past two months, ranging from the entry-level BLON BL-03 to ultra-high-end IEMs from 64 Audio and Empire Ears. If you’re after a DAP that’s more coloured or tuned to emphasize certain qualities in your IEMs, the R8 might not be the best choice for you. With that in mind, the R8 does have its own sonic characteristics, both tonally and technically, that are consistent across the IEMs I used, so let’s take a closer look.


Tonality

The R8 is about as close to a reference source as I’ve heard, but thankfully not in a flat, analytical way. By reference I mean that the R8 adds very little to the character of the IEMs you use with it, but what it does add is done in a very subtle, refined and transparent way.

For example, there’s definitely some extra meat on the bass, more so sub bass, which – if it’s present in the music and within your IEM’s capability – gives a little extra kick, a touch more rumble, and a very natural decay. There’s no extra boost that I can detect in the midbass, maybe the slightest hint of warmth when paired with more neutral IEMs, but no more than that.

The midrange is rendered precisely and very clearly, not any fuller or thinner than you’d expect from your IEMs. Listening to how the R8 renders vocals and instruments that centre on the midrange reminds me of how I heard my IEMs with another flagship reference DAP, the Lotoo Paw Gold Touch. I think it’s how transparent and clear the vocals and supporting instruments come across, especially with IEMs that I know to be very transparent themselves.

Treble is where the R8 gives a nod to HiBy’s ‘house sound’, which has been advanced and improved here. HiBy’s approach has always been to render music with a more natural, ‘musical’ tonality, and that’s most apparent in the R8’s treble which, while being more detailed and extended than it was with the R6 Pro, for example, is still more relaxed than the typical clinical, overemphasized treble that some high-end DAPs go for in their singular pursuit of detail.

Another thing I’ve picked up in my time with the R8 is that it’s not a pushy DAP. By that I mean it’s not going to stamp its character all over the music, for better or worse. If anything, it actually has a fairly relaxed tonality. It can be dynamic with the right IEMs, but it’s not going to bring the alcoholic punch to the party on its own.

That said, neither is it bland. I find the R8 delivers music with great authority, with excellent control. Where IEM’s like 64 Audio’s Nio or Empire Ears’ Legend X might be prone to losing control of their uber-powerful bass drivers with some lesser DAPs (or even quality warmer-tuned DAPs), the R8 controls them with a firm but deft grip. Not once have I heard the bass on either IEM as too loose or flabby or thick with the R8, nor the treble too nonchalant.

Technicalities

Where the R8 presents a bigger departure from the R6 Pro (and all the other midrange DAPs I’ve heard to date) is its technical ability. At first listen the word that came to mind most often was refined.

The R8 delivers whatever it’s playing at a very high technical level, but not in a jarring, wow-factor way. You’ll hear music with a wider, deeper stage, for example, especially compared to less capable DAPs, but it’s not done in an unnatural way, and if your IEMs are inherently intimate, then intimate they’ll stay. On wonderfully spacious IEMs like 64 Audio’s Tia Fourte, the stage is as magically wide as you’d expect, with the R8 easily capable of rendering the full depth, height and layers in the music.

While the tonality is slightly north of neutral, and natural rather than analytical, the R8 makes the most of its quality internal components to squeeze tremendous detail from almost every IEM I’ve used with it. Even the ‘lowly’ BLON scales up nicely.

It doesn’t fake detail, nor does it warm up the sound too much to smooth it over (despite the dual AK4497 DACs’ reputation for their smoother character). Make no mistake, the R8’s sound is silky smooth, but not at the expense of resolution.

If you have an IEM that revels in minutae microdetails, then that’s what you’ll hear. If you use a thicker, meatier IEM, the R8 won’t stand in your way or dilute its impact in any way. But unlike some DAPs, it won’t add this character on its own, nor artificially boost what’s not already there – it’s up to your IEMs to do most of the work.

Noise and power

One of the criticisms I’ve heard levelled at the R8 (and the R6 variants before it) was a tendency to push the noise floor just a touch too high, especially with very sensitive IEMs. While I have my own feelings about the merits – or lack thereof – of super-sensitive IEMs like Campfire Audio’s Andromeda and Solaris, I can honestly say the R8’s noise floor is the ‘blackest’ I’ve heard with the IEMs I’ve used with it (and with previous DAPs).

No question, the R8 is a very powerful DAP. With more the 1 Watt of power at 32 ohms out of the 4.4mm balanced output (which translates to significantly more wattage at the 3-, 6-, 10- and 14-ohm sensitivity of my IEMs), there is far more headroom than anyone would actually need for IEM use. But in my experience, it’s very clean power, even in Turbo mode (which was designed for full size headphones, but somehow makes my IEMs sound better too).

If you’re into numbers and measurements, the R8’s absolute noise floor is lower in both single-ended and balanced modes compared the R6 Pro, despite having more power on tap. One caveat to this: there are many who I know and trust that have keener hearing than mine who can sniff out even the faintest hiss from IEMs than I ever could, so don’t take my word as gospel. But even they would agree that using the R8 single-ended without Turbo all but eliminates any hiss, even with pointlessly oversensitive IEMs (there, I said it).

Pair-ups

In case I haven’t made my point clearly enough above, the R8 is an ideal match for just about any IEM (and probably most full-size headphones too). But that’s not to say it’ll be ideal for your IEMs.

If you’re looking for a DAP to counterbalance one or other characteristics – for example, if you have a very bright-leaning IEM and want a DAP that would naturally tone down its brightness (with a slightly rolled or thicker treble response), the R8 isn’t that DAP. Likewise, if you have an IEM that’s a bit too bass light for your liking and want a DAP to fill in the missing octaves down low, there are probably better options than the R8.

That said, if you’re looking for a DAP with a very linear, transparent but still natural sound, that’s the R8. It will effortlessly elevate any IEM to its full sonic potential without changing anything about it, making the most of what it already has without embellishing. IEMs that scale well with a better DAC or amplification will definitely benefit from what the R8 has to offer in both departments.

To illustrate the point, here are some examples from my personal experience:

64 Audio Tia Fourte – this is 64 Audio’s current flagship hybrid IEM, and is renowned for its resolving power, wide stage, microscope-like detail retrieval and precision imaging. It’s also a fairly bright-leaning IEM, albeit being balanced overall, and the R8 doesn’t mask any of these traits. Play a poorly recorded track or something that’s mastered too thin or bright, and you’ll get the unforgivingly harsh sound you’d expect with the Fourte. But play a reference recording and the R8 gives Fourte every nuance of the recording. You’ll literally hear everything the Fourte is capable of, and nothing that it’s not.

Empire Ears Legend X – probably the best bass you’ll ever hear with an IEM, if you consider big, bold, natural, resolving, textured and infinitely deep bass as ‘the best’. But Legend X is so much more than bass; it’s a highly technical, refined and natural IEM in its own right, across the spectrum, and the R8 plays it like a master conductor. If you’re looking for a wild basshead experience with the Legends, you’re probably not going to find it with the R8. It’s far too polished and disciplined to let the bass run loose. Nor will you hear any treble spikes the Legend X is said to have with some sources. I haven’t heard the Legends with another DAP, and frankly, I don’t need to.

64 Audio Tia Trio – this is the ‘wild child’ of the 64 Audio lineup. It has a bashful energy to it that makes Fourte blush. It’s a party animal, and while some would want to control its base instincts, the R8 is happy to let them loose. Still, the smoother, more relaxed nature of the R8 gives the Trio exceptional range with well-recorded music, while its bass response with high-energy EDM is palpably visceral. Excellent synergy here, if the Trio is your cup of tea.

BLON BL-03 – it’s not going to win any technical awards, I know, but the BLON has one of the very best tonalities of any IEM I’ve used, $3600 Fourte included. It’s such a warm, organic, balanced tuning that makes almost any track from any genre sound superb. It’s also far more forgiving than any of the flagship IEMs in my collection, probably a combination of its smoother tuning and lower resolving power, but connected to the R8, it sounds so much better than its cost of entry suggests. Pair it with a balanced cable and it even scales up superbly, to a point of course.

Stability

In the frantic rush to get new products to market, this is the one aspect of modern DAPs that I feel is too often overlooked by many, not least by otherwise experienced audiophiles. What’s the point of having a super-fast, feature-laden, superb sounding flagship DAP if it constantly glitches, the software is incomplete or limited, it fails to charge properly, or doesn’t give you the seamless experience you should demand at this level?

This is where stability comes into play. I appreciate that, as a niche product in a niche market, most DAPs are going to be compromised in one way or another. Even the R8, with its fairly modern architecture, still lags behind mass-produced modern smartphones with the latest processors and upgradable Android operating systems.

But none of this is an excuse for releasing an ‘unfinished’ device. If anything, using slightly older SoCs and more mature operating systems should add up to even better stability, but in my experience, that’s not the case. Even HiBy has had its fair share of disappointing issues with previous DAPs, the R6 Pro’s notorious EMI issues being one example, the original R6’s oddly high output impedance another.

Though neither of these are strictly stability issues, both impacted user experience. That’s how I personally define stability – the lack of anomalies or issues that negatively impact the user experience. In that regard, touch wood, the R8 is by far the most stable DAP I’ve used to date. Everything seems to work as intended, from the very first bootup. Apps install and work flawlessly, basic features like gapless playback and bitperfect support are there from the start, streaming services function as expected, and I’m yet to encounter a spelling mistake or grammatical error in the display of a song title or interface element.

As polished and refined as it sounds, so the R8 appears to be very stable. That said, I’ve seen anecdotal evidence that some units do have stability issues. I’ve personally seen an R8 with a corrupted display, requiring a full system reset to fix it. I’ve heard of another that reboots sporadically, one with backlight bleed, and one that drained its battery overnight. None of these issues are unique to the R8, and HiBy (and its resellers) are on the ball when it comes to technical support.

My own R8, thankfully, has never been anything but stable. If I had to nitpick, HiBy forgot to grammar-check its English firmware update notifications, but I only noticed that because of how jarring they are compared to the overall polish of the rest of the UI.

I don’t for a minute excuse any of the issues above as one-offs, but at the same time don’t accept that this is just the nature of living on the bleeding edge. In any other premium product category, basic quality control issues would never be tolerated as much as they are in this hobby, and as users we have a collective responsibility to hold DAP makers to a much higher standard.

As long as HiBy continues to be responsive to issues that do arise, and the R8 continues to be an impressively resilient device, I’ll continue to recommend it for its stability as much as I do for any of its other qualities.


Verdict and closing thoughts

With the HiBy R8, it feels as if the flagship Android DAP has finally come of age. Some will argue that summit-fi DAPs like Astell & Kern’s SP2000 have been delivering a premium Android-like experience and top-shelf sound at the highest level (and price bracket) for longer, but even they can’t offer the fully open, virtually limitless Android 9 experience of the R8. In fact, only one other current flagship DAP I know of supports open Android 9, iBasso’s DX300.

Not only has the software caught up to modern smartphones (more or less), now the hardware has too (more or less). The R8 (and DX300, to be fair) don’t quite scale up to the latest smartphone platforms, but because their system software is slimmed down and optimised, their real-world performance should be very close to that of phones with nimbler hardware. What is certain is that no other flagship DAP, not even the SP2000, comes close to the processing power of the R8 and DX300.

You could argue neither the software or hardware are really important, and sound quality is the only criteria a DAP should be judged on, to which I’ll say you’re either wasting your money on an Android DAP, or seriously compromising on the experience (and benefits) a true flagship DAP should deliver.

If sound is your only barometer but you still want the benefits of a modern Android system, save your money and buy a high-end portable DAC/amp that uses your phone as a source. If Android isn’t important at all, there are some excellent non-Android flagships that are equally fast and full-featured, like Lotoo’s superb PAW Gold Touch.

The R8, for me, transcends every other Android flagship DAP in delivering the most complete package of them all, including:

• Premium hardware and build quality, inside and out
• The fastest Android hardware platform in a DAP
• The most modern open Android system in a DAP
• The latest wireless connectivity, from high-speed, dual-band WiFi to Bluetooth 5.0 and all major hi-res and low latency codecs, including HiBy’s 1200kbps UAT
• The largest battery of any current DAP
• Built-in hardware sensors for screen rotation, tap to wake and tap to sleep
• A colour-accurate 1080P retina display
• Flagship-worthy sound quality, from tonality to technicalities
• Generous, premium packaging, storage and protection accessories
• A stable software experience with frequent and responsive firmware updates
• A reference-grade tuning that doesn’t impose on the sound of your high-end IEMs

Does it have any shortcomings? Certainly. There’s no such thing as the ‘perfect’ device, especially in such as fast-evolving product category. Quality control has been questioned by some, and there’s no question HiBy could have pushed the envelope even further with its included accessories or storage options for the asking price.

That said, the R8 puts a marker in the ground for where flagship DAPs should be in 2021. Some might prefer the sound profile of other DAPs, but that’s as true for the lofty SP2000 as it is for any number of mid-fi or lower-end DAPs. None of those DAPs, truth be told, hold a candle to the R8’s combination of versatility, functionality, power, sound quality and stability.

Going forward I expect newer DAPs to overcome some of the R8’s limitations and exceed its capabilities, at even lower price points. That’s the nature of the beast. But for now, the R8 presents the most compelling example I’ve seen of the complete flagship DAP, an example that many others – including HiBy – will no doubt follow in the months and years to come.



Recommended reviews (for DAP comparisons and other pairings)

Twister6 – HiBy R8 – Turbo Charged! (the standard for portable audio reviews)
Headfonics – HiBy R8 Review
Headfonia – HiBy R8 Review

I was first introduced to Dekoni Audio products when the fabric earpads on my newly-acquired Focal Elear fell apart. Little did I know at the time that replacement earpads made from genuine sheepskin leather could not only make the headphones sound better than the original pads, but also cost half the asking price of new Focal pads.

In fact, the Dekoni pads impressed me so much that I was surprised to find they weren’t featured in the Head-Fi showcase (fixed that), and that they hadn’t been reviewed before (fixed that too).

Then this happened: the pads that I considered the finest ever made for a headphone – the premium brown leather lambskin pads of my Audeze LCD-3 – were accidentally nicked and torn when I set them down on my desk, much to my shock and dismay. After all, how could such a quality pair of pads that were still in as-new condition be so easily damaged?

Not one to panic, I coolly remembered a recent announcement from Dekoni on their new range of Elite pads for the LCD series, and rushed online to find out more. A few weeks later, my previous favourite pads were replaced by my new favourite pads – the Dekoni Elite Sheepskin for LCD – and my LCD-3 has never sounded or looked better.

Full disclosure: Dekoni sent me two pairs of their new LCD pads – Elite Sheepskin and Elite Fenestrated Sheepskin – in exchange for my objective and unbiased review, with no guarantees or demands of any sort on my findings. The views expressed below are entirely my own, and were not influenced in any way by Dekoni or other interested parties.

Unboxing and first impressions

Having already bought my first pair of Dekoni earpads, I knew what to expect when the new LCD pads arrived: a set of well-crafted, tastefully decorated and labelled glossy boxes, complete with a magnetic latch and ample room inside to house two pads without damaging them in transit.

Compared to how Massdrop shipped me a pair of Elex pads – in a flimsy plastic packet stuffed inside a cardboard envelope without any markings, branding or (more importantly) protection – Dekoni’s approach is a step above, and most welcome. Not quite an Apple-esque experience, but as close as you can get for a set of replacement headphone pads.



Removing the enclosed pads, I was immediately struck by how soft they were. Coming from a pair of ultra-soft lambskin pads on the LCD-3, the Dekoni’s sheepskin is perhaps not quite as soft to the touch, but certainly softer than some other lambskin pads I’ve used (including ZMF’s Ori, Auteur and Eikon pads), while still appearing appreciably thicker and therefore stronger.

Compared to the original LCD pads, the Dekoni pads are notably thicker on the rear side of the angled exterior, by a good half centimetre or so. The memory foam appears to have been cut in multiple layers, with the divide between layers visible through the leather, but you wouldn’t know it unless you look at it closely in the right light. This doesn’t affect performance or appearance, but it’s something I picked up so worth a mention here. The foam itself is firmer than the non-memory foam used in the original LCD pads, so compresses less and retains its shape more when worn (more on this later).

Installation and comfort

Audeze weren’t too smart when designing their headphone pads. Given the superb quality and materials used, the complete absence of a removable mechanism for the pads – be it a lip for the pads to wrap over, or holes for disc to slip into – the LCD pads are crudely glued onto the metallic headphone cups.

This means that removing the pads also destroys the pads – or at least, it destroyed my pads. The glue is so strong that the entire top layer of prized lambskin leather on the back of the pads came right off as I slowly and carefully pulled and removed the original pads from the headphones. Not only that, but a layer of leather was left behind on the cups! I would include a photo of what they looked like after all was said and done, but it’s probably too distressing for a PG-rated site like this one and is strictly against Head-Fi’s zero tolerance for gratuitous violence.

So, before you rush out to buy a set of replacement pads for your LCD headphones, just know that it’s a one-way trip. Once they come off, they stay off, unless you’re willing to stick them back with foam exposed to the elements.

Despite the trauma of the pad removal, once removed, the new pads were a pleasure to install. Each Dekoni pad comes with a pre-installed ring of 3M translucent double-sided film, and all you need to do is carefully lift off the paper backing, align the pads correctly, and carefully press them down against the cups (I suggest you watch thisYouTube video to learn how to properly remove and install LCD pads). 30 seconds is all it took to fit the new pads.



Of course I’m jumping the gun a bit here; having received two different sets of pads, I didn’t want to ruin them by permanently installing and then removing one to test the other, so before deciding on which of the two pads I’d ultimately use for my own headphones, I used removable double-sided tape on the three sets of pads (the two Dekonis and the original pads) to easily switch between them and test for fit, comfort and sound.

Speaking of comfort, the solid Elite sheepskin pads felt the most familiar, coming from a similarly solid pair of lambskin pads. It definitely isn’t as soft as the original pads, but that’s likely more a factor of the firmer foam Dekoni uses. The leather itself is supple and soft, but smoother and less creased than the Audeze lambskin, most likely due to lack of any wear on the Dekonis.

Both the sheepskin and fenestrated sheepskin pads were cool on the skin, although the fenestrated pads remained cool after a lengthy listen while the sheepskin pads became and remained warmer. Being leather I expect both will get warm on warmer days, but the fenestrated pads will likely breathe better and remain cooler for longer. The heat-activated memory foam of the Dekonis will also get warmer than the foam in the original Audeze pads, so if you live in a hot and humid environment you might want to keep a facecloth handy for the occasional wipe down.

Fortunately, being leather, with proper care and maintenance these pads should last many years, unlike Focal’s material pads that disintegrate a little too quickly when exposed to heat and moisture.



One other note worth making: the thicker pads and firmer foam could spell trouble for those of us with larger heads. I never considered the LCD-3 to have a particularly strong clamp, probably because the pillow-soft pads completely enveloped and collapsed around my ears, cushioning any effect of the headphone’s hefty weight. With the Dekoni pads, you may initially feel the stronger clamp, especially if using the new Audeze suspension strap.

I have a relatively large head, but even so the clamp wasn’t uncomfortable, just noticeable. Luckily, I still had several rungs of extension left on the headband yokes, so increasing the yokes one click loosened the clamp closer to what I was used to with the stock pads. Also, as the foam gets ‘activated’ by heat from your face, the pads will conform and distort, making them more comfortable for extended listens. With extended use the leather will likely soften further, transforming the Dekoni pads into the comforting cushions I know and love.

Sound impressions

I imagine some of you may have skipped to this section first, so let me get straight to the point before diving deeper into specific examples of how the LCD-3 sounds with the Dekoni pads: the Deskonis DO change the sound of the LCD, very slightly and positively in the case of the sheepskin pads, more obviously in the case of the fenestrated pads.

To my ears, the fenestrated pads changed the LCD’s rich, deep and layered sound a touch too much for my liking, but that’s not to say the changes were all negative. In my notes below, you can decide for yourself if you think these changes would better suit you, or if you’d rather keep to the tried and tested sound of the original pads and the Dekoni alternatives.

The first thing I noticed about the Dekoni pads was their thickness, and how the memory foam was firmer than the foam in the stock pads. Putting aside the effects of fenestration for now, this meant both Dekoni pads hold your ears further away from the drivers. This theoretically can impact the sound of the headphones, although in truth the extra distance is not substantial enough for a major shift in frequency response. What it does do is widen and deepen the soundstage ever so slightly, most notably with the solid sheepskin pads. I suspect the fenestrated pads filter the sound in ways that also affect soundstage, widening it ever so slightly.

Paul Simon’s ‘Boy in the Bubble’ from his masterpiece album Graceland shows off the LCD-3’s deeper stage with the Elite sheepskin pads, whereas the fenestrated pads sacrifice a bit of depth for more air but also more width and an overall more diffuse sound compared to the heft of the solid pads.

The LCD-3 is often lauded for its fast, clean, deeply extended and perfectly weighted bass, and the Dekoni sheepskin pads further reinforce that impression. Lorde’s ‘Royals’, my go-to test track for upfront bass impact, hits deep and hard with the original stock pads, and even more so with the solid Dekoni pads. It’s as if the room size has increased, and the impact of the drum reverbs hang in the air a little longer than before. Interestingly the fenestrated pads don’t lose much bass impact with this track, although Lorde’s vocals do come across slightly brighter than both the original and solid pads, and also a smidge thinner if I were to be critical.

That added thickness from the solid Dekoni pads doesn’t come at the cost of the natural air and sparkle that I really enjoy with Audeze’s revised (post-2016) LCD-3 Fazor drivers. I certainly wouldn’t want the sound to be any thicker, although fans of the pre-fazor warm-and-gooey LCDs might beg to differ. In fact, I appreciate the extra heft, the slightly longer decay, and the truer tones of bass notes.

Made In Heights’ eclectic electronica in her ‘Wildflowers’ track sounds bigger and bolder with the solid Dekoni pads, with less glare and more focus on her sugar sweet vocals, while the fenestrated pads render the track with a softer sheen, excellent separation and a touch more emphasis in the upper mids.

Voices are better placed in the mix with the solid pads, while the fenestrated pads even out the FR, injecting more air into the midrange and treble than the stock and solid pads. If you prefer your LCDs a touch brighter and cooler, the Dekoni fenestrated pads might just be the subtle tweak you’ve been looking for.

Closing thoughts

Dekoni have hit another huge home run with their family of Elite LCD pads. Not only are they well presented, beautifully made from premium materials, exceptionally comfortable and easy to install, they also give you the option of keeping intact the LCD’s already superb sonics, or tweaking them slightly to taste.

While removing the stock pads can be traumatic for some, this isn’t Dekoni’s doing, and with luck Audeze will rethink their pad installation design for future LCD revisions. That aside, Dekoni’s pads offer a viable – and in my opinion preferable – alternative to Audeze’s already excellent pads, and significantly better value at around half the price of original pads.

Just keep in mind comfort issue and clamp force, but if you have a normal noggin, that won’t be an issue. Also keep in mind how the fenestrated pads change the LCD sound, and whether or not that’s to your liking. If you’re undecided, my suggestion would be to buy both, and soft-install each of them to hear the difference before deciding for yourself. In my case it didn’t take long to decide on the solid Elite sheepskin pads for my personal use.

Unlike the Focal Elear, for which I consider a pad swap mandatory, the reasons to swap pads on an Audeze LCD are less compelling. However, when the time comes, I wouldn’t hesitate to go with Dekoni, safe in the knowledge I’m getting an even better product for less money – something Dekoni is getting an admirable reputation for these days.

I've been a fan of Focal's Elear for some time now, having first heard them about a year ago at a time when I was just starting out on my head-fi journey. Fast forward a year and I finally bought a pair of my own, inspired by the sudden and frightful drop in the value of 'used' Elears following the unexpected announcement of Massdrop's Elex variant.

It seemed to me, given the hype about the 'new' Elear and how the Elex 'fixed' the quirks in the original Elear's sound, that something must be patently wrong with a headphone I knew only to be highly resolving, incredibly dynamic and very lifelike. After all, why else was I able to snag it for less than half the original retail price in such good condition?

The so-called 'fix' of the Elex was, by all accounts, its new earpads - apparently a simile of Focal's Clear earpads, made of the same material but in a darker shade. These were supposedly a step up from Elear's older microsuede earpads, both physically and sonically, and in the days leading up to the arrival of my Elear, I must admit to being worried that I'd taken a false step.

Something's amiss

And so it was, when I first opened up the rather posh-looking box that housed my not-so-new Elears, the first thing I looked at was the pads. Indeed, something was amiss. The Elear I first saw way back when was freshly unboxed, and consequently had fresh and plump earpads that felt nothing short of luxurious. The Elear I was now holding was clearly well worn, although the only sign of that wear was in the earpads.

Everything else looked and felt as I remembered it, but the pads, rather than full and lush, were slightly depressed, slightly misshapen, with the material starting to fray and frizz - as any suede-like material is wont to do after exposure to skin oils and clamping pressure.

Despite their appearance, once the headphones were mounted and playing, all thoughts of mucky earpads disappeared and only music remained. The sound was as slick and punchy as I remembered it, only now I had more time to listen at length and form a proper impression of a headphone that launched to such wide acclaim not that long ago.

Time for a change

To be fair, I'm not sure what some people are smoking when it comes to the Elear. As a huge fan of female vocals, I half expected to be hearing my favourite tunes skewed and distorted by the so-called 'midrange suckout' the Internet deemed the Elear's one big downfall (now remedied by the Elex and its fancy pants pads). But I heard nothing of the sort. Yes, there was an obvious dip in the upper midrange on some tracks, maybe a bit too pronounced for some, but the way I heard it, it made sense to de-emphasise this region when every other frequency was so full and in-your-face awesome.

Despite my positive impressions, try as I may I couldn't get the thought of the poorly made pads out of my mind. This was clearly a premium headphone, with a sound signature that suited my taste to a tee, and yet it was badly let down by some poor design choices. I mean, who in their right mind thought microsuede (or whatever this material is made of) was a good idea for the one part of the headphone that gets touched, compressed, heated up and oiled every day, all day?

It was time for a change. The pads had to go. But, given how pad sensitive the Elear could be (and most likely was, given the positive, almost anti-Elear reception of the Elex and Clear), I couldn't just buy any replacement pads. I could, of course, just order a pair of original Elear pads, but given how little I thought of their quality, and also the fact that such shoddy quality would cost me more than a third of what I paid for the actual headphones, I needed to look elsewhere.

Long story short

I'm going to fast forward a bit now, to the part where I take hold of a brand new, beautifully packaged pair of shiny new Dekoni Audio pads of the fenestrated sheepskin variety. To cut a long story short, having decided to rid myself of the gunky stock earpads, I first ordered a set of Dekoni's Elite Sheepskin pads, but for some reason the sound wasn't quite right. They looked the part, and the leather was oh-so-much better than the suede (I guess that's why you pay the big bucks for the Utopia, right?), but the sound, it just wasn't Elear. Being leather, and solid, they were also a touch too firm and 'hot' on the ear, although this is probably more a factor of the Elear's pad size and design, because all my other headphones have generously large and plush earpads that don't suffer the same downsides.

So I got in touch with Tal from Dekoni, told him my story, and for the price of shipping alone, he was king enough to send me a pair of fenestrated pads. A few (more) weeks later, and here I am, happy as someone who just had a lightbulb moment. I knew it from the minute I opened the very Apple-like display box and held the new pads in my hand. I expected them to be softer than the solid pads, and indeed they were. They were also much cooler on the ear. Whatever formula they used to make these pads, it works. But best of all, my Elear was my Elear again - playing back every note the way I knew it should be.

Yes folks, it's true: Dekoni's fenestrated sheepskin earpads 'fix' the Elear, just not in the way you think!

Have an Elear? Get new pads.

About a month ago, having spent a few days with the new pads and working through my library of familiar tracks, I wrote the following on one of the Focal Elear Impressions thread:

I’ve just ‘upgraded’ my Elears with the Dekoni fenestrated sheepskin pads and I’m more convinced than ever that these are some of the most underrated headphones around. Yes I know they were hyped to death at launch, but mainly for their punchy, dynamic sound. With the new pads I’m finding them just as suitable for just about any genre - from classical to light acoustic to female vocal to folk to rock.

The imaging and layering is superb, the bass is never overwhelming and perfectly weighted, the detail is exceptional and the soundstage is perfectly spacious and airy.

I think the original Elear pads - however comfortable - are also its downfall. Poorly made, mine have already degraded considerably, and as can be seen with the Elex, a different material and design makes this headphone feel completely different.

And so I'll say it again, these pads fixed the Elear for me because they made them a pleasure to wear, and a pleasure to use. Comfort and looks might not be important to some, but when you're buying a premium product like the Elear, you want to be proud to look at it, show it off, and wear it. Of course the most important thing about a headphone is how it sounds, and if anything, these pads make the Elear sound as good if not better than the original pads. If there was a slight dip in the mids or lower treble, I'm not hearing it, and possibly hearing it much less than I did with the stock pads.

The bass is there, oozing detail and full of dynamic punch - almost as punchy as my closed back ZMF Attcius, may I add; the mids are there, sweet, accurate, not too forward and definitely not recessed; the treble is sparkling without ever being bright or sibilant. It's just a brilliant listen, and with good files, a good amp and a good dac, the Elear is probably the best all-rounder I've ever owned.

And in no small part, that's because of the pads.

Introduction

When I heard the first rumours about a new flagship IEM from HiBy it took me by surprise, not because I didn’t know HiBy was in the IEM business, but because, until now, their efforts were mostly lower-priced companion IEMs for their outstanding range of DAPs.

Zeta is far more than that. It’s a premium tribrid flagship IEM that combines nine drivers in each titanium-steel earpiece, including four of Sonion’s newly-released third-generation electrostats. It also features a five-way crossover and five independent tubes that connect and conduct the mix of DD, BA and e-stat drivers, to great effect I might add.

To be honest, what’s more surprising is that in the months that followed the initial announcement there hasn’t been more fanfare about this IEM, but perhaps what I hinted at earlier – that HiBy is better known for its DAPs – is the reason why. I think Zeta has the potential to change all that, or at least put HiBy in the mix when it comes to choosing a modern kilobuck IEM.



Packaging, design and fit

Everything about Zeta, from the unboxing to first impressions, feels premium. The multilayered box contains clever cutouts for the IEMs and different compartments for accessories, and it’s obvious that quite a bit of thought and preparation went into the unboxing experience.

The accessories themselves are premium too. HiBy includes a round (faux?) leather case in a similar blue-green colour to the leather case supplied with the flagship RS8 DAP. Inside the case is a balanced (4.4mm) 8-wire, 2-pin pure OCC cable, sheathed in a soft and supple PVC that contains the exotic Lapis Lazuli compound (which gives it its blue hue). Also included is a full set of three different types of tips: medium silicone, soft silicone (for a deeper fit) and silicone-wrapped foam (for better isolation).

Titanium seems to be flavour-of-the-month for premium products, and Zeta continues the theme with precision-milled titanium and stainless steel earpieces. Titanium is a lightweight metal, so despite their size, the earpieces are very light, ergonomic and silky smooth to the touch. Even with slightly thicker nozzles, I found fit, once seated properly (more on this below), to be very comfortable indeed, although there’s no way I’m getting a deep fit with these.



I do have two issues at this point that need some addressing. First, the cable, while initially looking quite special, tends to lose its braiding shape when folded or stored, which gives it a ragged appearance after a while. If you take your time twisting it back into shape, the braids do tighten up again, but it’s worth noting that the shape doesn’t hold up as well as other cables I’ve used – not good for my aesthetic OCD. Ergonomics are very good though, with comfortable ear guides and zero microphonics, and the cable is very soft and supple, with excellent hardware quality at both ends.

The other, more pressing issue (if you’ll excuse the pun) is a vacuum pressure/pain sensation I get when using Zeta with its stock tips, and numerous third-party tips as well. This might well be an anomaly of my ear anatomy though, because I haven’t read about this issue elsewhere, and speaking to other Zeta users, it hasn’t been mentioned. It’s also unusual; I’ve had this suction issue before with unvented IEMs like Oriolus Traillii, but never with a vented IEM like Zeta.

Thankfully there are certain tips, like Azla EarFit, that seem to eliminate the problem for me, but it’s something to keep in mind if you’re sensitive to pressure pain in your ears.

Overall, Zeta’s presentation and industrial design is impressive. HiBy has clearly gone to great lengths to make sure its premium IEMs are made, styled and presented as such, and have succeeded admirably. Considering Zeta is priced significantly lower than many other flagships in its class, it appears to be a great value buy. Whether or not that holds up in practice, we’ll find out next.



Sound impressions

I tested Zeta using a broad selection of test tracks from my library, which predominantly comprises newer music of the female vocal indie persuasion, along with pop, synth-pop, classic rock, cinematic and singer-songwriter classics. I also sampled various other music types I occasionally listen to, like EDM, ambient, classical and vocal jazz, and where relevant, I’ve included track notes in the review.

All listening was done with a variety of sources too, primarily using HiBy’s flagship RS8 DAP (which, as you’ll see in the pairings section, is an almost perfect companion for Zeta for my preferences). With a sensitivity of 112dB and low 9-ohm rating, Zeta is very easy to drive, but seems to scale up nicely – especially with bass control and stage dimensions – given more power. As such it can be used with just about any source, including basic smartphones, but handsomely rewards more powerful amplification and DAC quality.



Tonality

I hear Zeta’s tonal shape as a skewed-left W, with elevated but well-controlled bass rising just above a centred midrange with very slight upper midrange emphasis, and a relaxed treble with some mid-to-upper treble accents. This is by no means a V-shaped IEM since mids are clear and distinct despite the bass emphasis, and isn’t quite U-shaped either since treble is not pushed too far forward.

Bass is the star of the show, for me (which, if you know me, bodes well for the remainder of this review). Play the opening bass drum salvo to A Fine Frenzy’s Elements and you’ll hear a satisfyingly deep, powerful, visceral bass response, with a gloriously bouncy impact and the sort of natural decay you’ll only get from a good dynamic driver.

The balance between sub- and midbass is fairly even, with enough physical rumble down low to render the subtle sub-bass accents in Kristin Hersch’s Your Ghost, though it doesn’t quite reach as low as sub-bass specialists like Sony’s IER-Z1R. This is something I also noted in Lana Del Rey’s Video Games, where the sub-bass drops aren’t quite as emphasised as I’ve heard them, and yet don’t disappoint either.

There’s a tactile physicality to Zeta’s midbass on both the tracks above that gives the overall bass balance as reassuring weight. Real drums are rendered realistically across the frequency range, with accurate and natural impact and decay. Listen to the live and mostly instrumental rendition of Leonard Cohen’s Halleluja from Sincerely, L. Cohen and you’ll feel like you’re in the auditorium with the drummer.

Despite the bass excellence, Zeta is not a bass monster like some other modern sets. It doesn’t have the sheer elevation of Empire Ears’ Legend X or EVO, or the unapologetic midbass overload of FiR Audio’s Xe6. It’s a tactile bass with superb texture, particularly when paired with a high-end source like HiBy’s RS8. The ripples of bass texture in Lily Kershaw’s Always & Forever are one of the highlights of that track for me, and the combination of Zeta and RS8 makes the absolute most of the experience.



For a bass-forward set, Zeta is remarkably balanced. Midrange notes, from the lowest male vocal registers to the highest, sweetest upper midrange female vocals, are rendered clearly, emotively and without veil.

Nothing pushes my audio buttons more than the synergy of powerful bass and clear, full female vocals, and Zeta absolutely nails it here. The contrast of deep synth drums with Linda Ronstadt’s heavenly-sweet and nuanced voice in Dreams to Dream is tear inducing, as is the interplay between the upright bass plucks that play against Lisa Ekdahl’s sugary vocals in Nature Boy.

The latter is an excellent example of Zeta’s midrange clarity, resolve and timbral accuracy, piano keys striking realistically across the registers, the highest notes sitting just in front of the upright bass on the stage, and perfectly balanced with the distinct and separated vocals. There’s absolutely no veiling of the midrange, even in bass-laden tracks like Lorde’s The Louvre.

In fact, vocals, especially female vocals, are pushed slightly forward on some tracks, likely the result of the upper midrange lift. This does mean that tracks with already-forward mids can get testy at higher volumes, but I listen louder than most and it’s rarely an issue I’ve come across. You won’t want to turn up the dial too high on Angel Olden’s Lark, for example, but that’s true with most IEMs to be fair, and a slight reduction in female overtones using HiBy’s excellent MSEB EQ on the RS8 quickly tames any errant upper-mid recording issues.

If Zeta has any strikes against it at all, this lack of absolute midrange refinement might be one, at least when compared to multi-kilobuck midrange specialists like Vision Ears’ Phönix or Oriolus’ Traillii. It’s a nitpick, though, and the sheer quality of the midrange delivery more than compensates for a few rough edges on the rare extreme track, in my opinion.



This quality is consistent, too, from bass to midrange and especially treble. With a new generation of quad EST drivers, you’d expect Zeta’s treble to be fast, fluid and resolving, and while it is, it’s also more restrained and less ethereal than most other EST-infused treble I’ve heard before. It also has plenty of sparkle, with the glimmering highlights in Lisa Gerard’s Now We Are Free adding a spine-tingling element to what is an already transcendent track.

I sometimes find EST treble to dominate and dry out the upper harmonic registers of female vocals, adding too much air to the mix, something that turned me off from Vision Ears’ EXT for example. Listening to Maggie Rogers’ pristine vocals on Satellite (recorded in a high-school music studio when she was seventeen), and every ounce of sweet warmth that I was missing with EXT is back with Zeta. I’m still ‘feeling’ plenty of air, and while it’s not adversely affecting vocals, those who want their EST air dialed up to max might want to look elsewhere.

HiBy tastefully dips lower treble by 3-4dB (to my ear anyway, I’m yet to see an official graph), which totally eliminates any semblance of sibilance on just about any track. Missy Higgins’ cover of Shark Fin Blues is a case in point, where too much lower treble energy makes for piercings esses and tssts on this track. With Zeta, Missy’s voice is as smooth and sibilant-free as I’ve heard it.

That said, the slight upper mid boost can make the contrast between upper midrange and the lower treble dip seem more pronounced than it should be, but again, this is rare and very track dependent. The lower treble drip doesn’t rob Zeta of any energy or clarity in that region, and the equally-tasteful mid-to-upper treble boost ensures that treble doesn’t drop off a cliff.

That boost adds a sprightliness to orchestral strings that makes listening to Max Richter’s rendition of Vivaldi’s Winter 1 an absolute pleasure. The resolution advantage of the quad EST’s is most evident on this type of track, as is Zeta’s natural timbre. The combination of the highs of the strings and the lows of the bass on this track is another example of the interplay I mentioned earlier than makes Zeta such a pleasure for me personally.

Overall, I find Zeta’s tonality strikes a delicate balance between warmth and clarity. It’s unquestionably coloured, but not to the point where it dominates with colour (like Xe6, for instance). Some will find the treble too polite, or the bass too punchy, but it also shies away from being too aggressive. That’s a good thing, in my opinion, but if you lean more intense in your preferences, you’ll probably want to try before you buy.



Technicalities

While it’s still a very pricey IEM at $1300, you’d expect some compromises compared to summit-fi IEMs that cost thousands more, and technical performance is normally where those compromises are made. Not so with Zeta, at least not to my ears.

One of the first things I listen for when evaluating IEM technical performance is stage size. If you want the widest stage possible, Zeta’s isn’t going to blow you away, though I don’t see that as a con. Ottmar Liebert and Luna Negra’s La Luna is a naturally-wide binaural recording and I’m not sensing any loss of that natural width with Zeta. It’s also got a depth to the stage that’s absent from many IEMs, with the clap effects in this track sitting notably deeper than some of the instruments, for instance.

Yanni’s cinematic Santorini is another example of how Zeta spreads out the stage very naturally. There’s nothing constricted or intimate about it, even though it ‘lacks’ the vastness of stage of an IER-Z1R or the holography of an Xe6, I’m not missing these qualities when listening to Zeta, which has its own character compared to those highly-revered IEMs.

Resolution is excellent for an IEM with a thicker tonal weight like Zeta. It’s not ‘fake’ resolution either, with treble being polite as it is. There’s not a single detail that I’m missing from Radical Face’s Welcome Home – and if you’re intimately familiar with this track, you’ll know how nuanced and detailed it is.

Whether it’s tiny vocal inflections and ‘mouth feel’ in Heidi Talbot’s closely-micced Cathedrals, or finger plucks on strings in Nils Lofgren’s reference-quality recording of Keith Don’t Go, Zeta doesn’t miss a thing. And it presents this detail without ever pushing the treble too hard, adding too much air, or leaning too bright. It all sounds perfectly natural and more importantly believable, which is probably an apt description of Zeta’s sound as a whole.



Yosi Horikawa’s Bubbles is another classic track where not only stage size and resolution but so many other technical elements come into play. I’m hearing a naturally large stage with above average resolution, layering, separation and imaging when listening with Zeta on high-end sources like RS8 and DX300 MAX.

Every ‘ball drop’ (excuse the crudeness, but how else would you describe it?) is perfectly resolved, with the different weight and material of balls and ‘bubbles’ clearly discernible. There’s no smearing of transients either, which is impressive given the powerful bassline that permeates this track. In fact, I’d go as far as to say Zeta presents this track more vividly and incisively than almost any other IEM I’ve heard it with.

So where does Zeta fall short technically? Probably the fine margins. Comparing to other IEMs, which I’ll summarise in the next section, Zeta doesn’t have the absolute clarity and resolution of IEMs like Sony’s IER-Z1R and Campfire’s Supermoon. It also doesn’t share the pinpoint precision of these two IEMs, but in turn is both more resolving and precise than Custom Art’s FIBAE 5, another set I rate very highly. It probably also lacks the sheer dynamism of IEMs like Xe6, and, as mentioned earlier, the stage dimensions of Z1R and Xe6 respectively.

But are these night and day differences? That really depends on how driven you are to extract the very last bit of technical performance from an IEM, how much you’re willing to compromise on tonal balance, and how much you want to pay for the privilege.

I personally haven’t heard an IEM with Zeta’s rich tonal balance that’s also an uncompromising technical performer, or put differently, none of the technically ‘flawless’ IEMs I’ve heard have Zeta’s combination of powerful dynamic bass, vocal acuity and pristine, edge-free treble in one package. Moreover, I feel Zeta’s technical performance is as good as any I’ve heard in its price tier, and better than some costlier options too.

As a nine-driver hybrid, it also has an inherent technical advantage over single dynamic driver IEMs while maintaining the coherency and natural timbre of their dynamic driver sound. Stage, resolution, and all the other checkboxes are a step-up from the likes of Sennheiser’s similarly-priced IE 900 and SoftEars’ $2,500 Turii Ti – save perhaps the clarity on the SoftEars – and I prefer Zeta’s tonality over both.

Overall, I find Zeta a capable kilobuck-level technical performer, and if you click with its tonal balance like I do, it’s an IEM that’s could win your favour over many of its better-known, more established competitors.

Select comparisons

Custom Art FIBAE 5 ($999). In my recent FIBAE 5 review I summed up Custom Art’s new tribrid custom IEM as ‘the consummate kilobuck all-rounder’, and Zeta doesn’t change that assessment.

Although I consider Zeta a more enjoyable IEM, FIBAE 5 takes an evenhanded approach to its tuning that will likely win broader appeal. FIBAE 5 combines bass that’s punchy but not quite as authoritative as Zeta’s, a clear but slightly softer and thinner midrange, and a treble that’s more extended and present, if a little peaky at times.

Zeta is a more accomplished technical performer, though you might argue that FIBAE’s cleaner midrange and planar treble give it a slight clarity edge. FIBAE 5 is comparatively conservative and relaxed, with Zeta more engaging, lively and fun.

As a package, Zeta ships with a better cable, nicer accessories, and while it’s difficult to compare a titanium-shelled universal IEM to a work-of-art resin custom, Zeta just about shades FIBAE 5’s still exceptional build quality for me.



Campfire Audio Supermoon ($1500). Another custom IEM I reviewed a short while ago, Campfire’s Supermoon is still the most technically gifted IEM I’ve heard in its price range, and while its tonality is far more divisive, for the music it plays well with, it has a unique sound that’s hard to beat.

Despite sporting a single planar dynamic driver, compared to Zeta, Supermoon is more resolving and quite a bit faster, though it lacks the dynamic contrast and punch of Zeta’s beautifully-tuned dynamic driver. Stage size is similar on both, with Supermoon perhaps a touch wider, and it’s hard to beat Supermoon’s instrument and vocal separation at this level, in my opinion.

Tonally I find Zeta’s balance and warmth more natural and organic than Supermoon’s ‘digital’ presentation. That’s not necessarily a mark against Supermoon, especially for those who prefer their sound cleaner and leaner, and both IEMs share an innate musicality that steers well wide of analytical. There’s no question that Zeta has the more accurate timbre, more realistic voicing, and significantly thicker note weight, especially in the upper midrange and treble registers.

As with FIBAE 5, it’s difficult to compare build and fit between Zeta and Supermoon. At this level, both are excellent, as well-made as any I’ve seen at any price tier. I do prefer Supermoon’s thinner, lighter and more ergonomic cable, and since I generally prefer MMCX connectors to 2-pin, Supermoon gets my nod here too. I know that’s not a popular opinion, though, so you might find the opposite to be true.



Sony IER-Z1R ($1,799). Sony’s peerless flagship is, to me, as fresh today as it was when it made its debut five years ago. Regardless of price, I’m yet to hear an IEM that delivers Z1R’s unique combination of liquid sub-bass, pristine female vocal clarity and pitch-perfect treble, inside a cavernous stage that presents the most lifelike, life-size soundscape I’ve heard in portable audio to date.

In Zeta, I’ve found an IEM that shares some of Z1R’s tonal traits, but mixes them up with its own flavour. Zeta has more midbass drive than Z1R, giving its bass a weightier, heavier and punchier character to Z1R’s textured, nuanced sub-focused rumble. Zeta’s midrange is audibly more forward than Z1R’s, especially male vocals, though Z1R still somehow edges Zeta for absolute clarity.

Where Zeta’s treble is sibilance-free and more relaxed, the Sony’s is more direct, incisive and clean, with a sparkle that’s truly class-leading. Some find Z1R’s treble too splashy with high-energy music, so picking between the two treble presentations will come down to preference. I find that both work equally well with most of my library.

Technically, Z1R is a step up from Zeta, which as I mentioned above, lacks very little in most departments. Z1R is tuned for clarity, whereas Zeta is slightly fuller and warmer, with thicker note weight. Z1R is more resolving, more precise, more open, painting with a finer brush as it were. That said, both sound lifelike and realistic, despite these differences.

Very few IEM manufacturers can challenge Sony from a packaging and build quality perspective, and HiBy is no different. Many will find Zeta an easier fit, however, with lighter and more ergonomic shells, but I’m one of the lucky few for whom Z1R fits like a glove (with the right tips, of course). As pretty and shiny as they are, Z1R’s Zirconium shells are also prone to micro scratches, which Zeta’s coated titanium alloy shells don’t seem to be.

Overall, the best compliment I can give Zeta in this comparison is that I have no hesitation picking it alongside Z1R to get the same level of enjoyment, especially from bass and vocals. Make of that what you will, but know that I can count on one hand the number of other IEMs I can say that about.



Select pairings

Zeta is a warm-sounding IEM for sure, but it’s not dark, nor veiled or dry. It’s also not so warm that it doesn’t play well with warm-leaning sources. It has great synergy with all my DAPs, all of which are warmer than neutral, but if you prefer a more neutral, lighter or brighter sound, the combination of Zeta and brighter sources may be more to your liking.

HiBy RS8. HiBy’s flagship DAP, RS8 features a pleasant warm-of-neutral tonality with a distinctly analogue-sounding R2R character, and amplification that elevates it to the top of the portable player technical performance charts too. To me it feels like Zeta was tuned with RS8 in mind, and I wouldn’t be surprised if some of the marketing materials from HiBy featuring the pairing were taken long before Zeta was a known entity.

Since RS8 is my baseline for Zeta’s sound, I can only compare it to other sources by proxy. Everything I’ve described about Zeta to this point is drawn mainly from my experience of it with RS8. Zeta does change its profile to some degree with different sources, but to me achieves an almost perfect symbiosis of sound and function – including the minor MSEB tweaks I touched on in the review – with RS8.



iBasso DX300 MAX. I recently purchased iBasso’s ‘flagship’ DAP as a replacement for the last of my desktop sources, wanting a transportable alternative with desktop-grade driving power for my IEMs. In the DX300 MAX I found what I was after, along with a smooth, slightly warm and somewhat organic sound profile despite its delta sigma DAC.

The biggest difference I hear with the DX300 Max with Zeta is its absolutely effortless bass control. Bass notes are tighter, and land with more impact compared to RS8 – which is itself a superb bass performer. ‘3MAX’ takes bass control to a different level, separating it even further from the other frequencies while sharpening its focus and resolution. Where it doesn’t quite match RS8 is in vocal purity, although I find Zeta’s midrange better-resolved and slightly cleaner with the iBasso.

I also hear Zeta’s treble to be a touch more relaxed and ethereal with the DX300 MAX compared to RS8. It’s also more resolving, with a grander stage in all dimensions.

Sony WM1Z. There’s something to be said about Sony synergy, which is the main reason I bought Sony’s ‘gold brick’ to pair with Z1R, but I’m happy to say it’s equally at home with Zeta.

Some might tell you to steer clear of warmer sources like WM1Z with Zeta, but I personally don’t find Sony’s flagship (non-Android) Walkman to be skewed too warm in the first place. Instead, I find that unique combination of excitable yet rich, smooth and expansive Sony house sound to work well with Zeta’s natural tonality.

I also don’t hear Zeta’s bass as elevated any further than it is with RS8, which is to say tastefully elevated but not overdone for my preferences. In some ways it hits harder than RS8, but doesn’t have quite the same resolving power as the HiBy, or the delicate control of the 3MAX. Midrange notes are clear and concise, reminiscent of the 3MAX, while treble is given a touch more bite than the HiBy and iBasso, making Zeta sound a touch more excitable.

Like Z1R, some say Sony’s Walkman is showing its age, but I still find it to be competitive at the highest level with modern DAPs, and given fresh sounding, easily-driven IEMs like Zeta, very much has a place in any collection where streaming and Android functionality are not a priority.



Closing thoughts

If you’ve made it to this point without skipping a line, you’ll know that HiBy’s Zeta is quite a revelation. Not only is it an excellent performer at its price point, it’s the complete package in almost every aspect I look for in a top-tier IEM.

Tonally, Zeta is a smooth operator, with a warm, inviting sound that doesn’t oversaturate the music with colour, staying true to the spirit of most modern recordings while adding some welcome meat to the bones of older, thinner-sounding productions. With a bass delivery that’s as precise as it is powerful, there’s a weighty foundation to almost any track I play, with an organic, natural midrange and a thicker, more relaxed treble that’s still sparkly when called for and has enough air for most.

Zeta is one of the few IEMs that lets me play right through my library, discovering new details and aspects to music I’m already familiar with, and I’m yet to find a track that has me reaching for the skip button. This is a rare quality that I prioritise and value above most others, especially when the price sits north of a kilobuck.

I’d be remiss not to mention the sub-par cable braiding quality, and the mysterious suction effect I get with certain tips, despite the venting. But these are nitpicks that are quickly forgotten once the music starts playing. I have even less to complain about in terms of sound quality, and while I’ve heard a more refined midrange to treble transition, there are few examples I can use to showcase a more appealing sonic presentation for my preferences.

Anyone who dismisses Zeta as just another companion IEM from a DAP maker is potentially missing the opportunity to hear one of the most enjoyable IEMs I’ve had the pleasure of reviewing at any price. In fact, at its price, I consider Zeta to be one of the best-value high-end IEMs you can buy today, and it gets my highest possible recommendation.



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This review first appeared on The Headphone List.

If you haven’t read my first impressions preview of the new Sennheiser IE 900, feel free to do so here.

Preface

The opinions expressed in this review are just that – subjective opinions, based on my personal music choices, listening preferences, and even my mood on the day. As such you should consider this (and really any) review as just another data point. If you have any questions about my preferences, the music I used, or anything else you’d like to discuss, feel free to leave a comment or PM me directly.

Full disclosure: Sennheiser loaned me the IE900 in exchange for my honest review, without fear or favour, or any expectations from me. I am required to return them to Sennheiser once I’ve written my full review, and have already purchased a pair of my own. That’s probably a bit of a spoiler for what’s to follow…


Introduction

Sennheiser is a name synonymous with headphones, some of which – like the famed HD600 / HD650 series and flagship HD800 – have earned their place as benchmarks for high-fidelity in the head-fi world.

The company has dipped its figurative toes into the IEM world too, but never quite attained the same stature in the smaller format of the game as it had with its lauded headphones. That’s not to say it hasn’t been successful, and its flagship IEMs did for a time earn widespread appeal and pioneered notable engineering firsts.

But it’s been a while since the IE 800 (2012) and IE 800S (2017) were flagbearers, superseded by a new generation of multi-driver IEMs from boutique manufacturers in the US, Europe and Asia. Despite releasing a series of new IEMs in recent years, purportedly for the ‘pro’ stage and music mixing market, the company waited until earlier this year to launch its first updated ‘audiophile’ IEM, the consumer-friendly IE 300, before surprising the market with its new flagship IEM, the IE 900.

Incidentally, behind the scenes, Sennheiser sold off its consumer audio division to Swiss-based Sonova, and despite suggestions that Sennheiser’s design teams will continue working with the new owners to develop future products, could the IE 900 possibly be the last original head-fi release from the famous German brand?

Considering how the IE 900 came to be, the legacy it represents, and the fact that the HD800 was the culmination of my personal four-year journey to find the very best headphone for the music I listen to, I immediately signaled my interest in the IE 900 almost as soon as it was announced. To my utter amazement, Sennheiser answered the call, and with the generous help of one of the best industry spokespeople I’ve had the pleasure of working with (thank you, @Evshrug), I had an IE 900 delivered direct from Bavaria to my review desk at the tip of Africa.

The Sennheiser IE 900 is an outlier of sorts in the modern IEM world, particularly at the pointy (read rather expensive) end of the market where only the most enthusiastic (read well-heeled) enthusiasts dare to go.

For one, it sports a single full range (or wide band, as Sennheiser calls it) dynamic driver, instead of the mix-and-match of dynamic, balanced armature, e-stat and other exotic driver combinations common to its competitors. It’s uniquely small, unusual even for a single driver dynamic. And it uses MMCX (rather than the more popular 2-pin connector) for its plastic-sheathed (rather than braided) stock cable.

But as you’ll soon see, all these design decisions have a purpose. While they may initially frustrate some users, who may prefer the contemporary ear-moulded aesthetic or take issue with the inability to ‘roll’ their existing, expensively-acquired collection of third-party cables, once you get to know the IE 900 (and navigate around some of its ‘quirks’), you’ll find yourself rewarded with an IEM that elevates, rather than stymies, the state of the art.



What’s in the box

The IE 900 comes in a compact box adorned by a classy image of the distinctive earpieces on the cover, flanked by the Sennheiser logo and ubiquitous Hi-Res Audio emblem, a must-have accreditation for any self-respecting audiophile in the 21st century. Inside the box you’ll find…another box, this time with no imagery, just a sleek, dark-grey motif, silky smooth finish, and embossed Sennheiser logo, with a velvety pull tab on the side that releases…yet another box with the contents you’re by now desperately trying to get to.

The first thing you see after you’re done playing Russian Dolls is the two glistening silver earpieces, looking ridiculously small in their pre-cut foam enclosure. Another tab lets you lift the foam away, exposing a date-stamped certificate of authenticity with a serial number and handwritten signature of your personal QC checker, a very nice touch befitting a premium product.

Digging deeper you’ll find a smorgasbord of standard-issue accessories, including a stylish gold-brown zippered carry case, three stock cables (one for each of the 3.5mm, 2.5mm and 4.4mm termination types), a selection of silicone and foam eartips (in small, medium and large sizes), a shirt clip for playing crocodiles while listening to music, a Sennheiser-branded cleaning tool for flicking your co-workers with the earwax that accumulates in your tips, and a plush cleaning cloth to offer your co-workers by way of apology when you’re done.

I’ve seen more lavishly presented flagships (Empire Ears comes to mind), and laughably spartan ones too (Oriolus Triallii, anyone?), but on the whole, I’d say the IE 900’s is a very pleasant unboxing experience indeed. You get everything you need in the box, and what you don’t get isn’t too expensive to source elsewhere (more on that later).


Form follows function

A closer examination of the IE 900 earpieces reveals exceptional build quality and precise craftmanship. The IE 900 housing is CNC-milled from a single block of aluminium with a finely ridged ‘fingerprint’ pattern making it both very distinctive and easier to grip. It would have been cool for every set to vary the pattern slightly, like its own unique fingerprint, though that would have no doubt added unnecessary complexity and cost to the process.

The earpieces are shaped in the fold-over style common to on-stage monitors, and even though that’s not their primary purpose, it’s a design that lends itself to a very comfortable, if somewhat intimate, fit. Sennheiser opted for industry standard MMCX connectors for the IE 900, but used slightly recessed earpiece sockets to improve contact longevity at the expense of compatibility with many third-party connectors.

If you’re going to cable roll, make sure to stipulate IE 900-compatible connectors, or risk your new cable not being able to latch on to the earpieces (as was the case with a spare set of MMCX to 2-pin adapters I tried to use unsuccessfully).

Inside the shells, Sennheiser stuck with their tradition of using a single 7mm dynamic driver, made of unspecified materials, extending a lineage that dates back to the original IE 800, and possibly even earlier. While the driver itself has undergone several iterations since then, the standout features of the current implementation is the addition of two important engineering advancements created specifically for the IE 900:

X3R technology – a fancy acronym for the three Helmholtz resonators milled directly into the earphone enclosure, designed to eliminate resonance peaks that can otherwise colour or adversely affect the sound coming from the driver. The resonators work in combination with the specifically shaped nozzle structure to regulate the airwaves generated by the driver and smooth out any errant peaks in the frequency curve.

Acoustic back volume – this small ‘space within a space’ sits behind the driver and supposedly affects the tuning of low-end frequencies, helping better shape and separate them from the midrange and further reduce resonance from the enclosure.

In the lead-up to the IE 900 launch, Sennheiser released a promotional video to highlight these specific features. Check it out below:



I’m no engineer, but to my layman’s ears, one of the standout qualities immediately apparent in the IE 900’s sound delivery is a silky smoothness with an almost complete lack of resonance, particularly in music where shouty vocals or aggressive piano strikes often result in fatiguing peaks with other IEMs (especially those tuned brighter, with strident treble, or over-abundant midbass).

I’ll make more mention of these qualities in the sound impressions part of this review, but as part of my research, I asked the man who led the IE 900 design team, Jermo Köhnke, how the specific function of these tuning technologies impacts real-world performance (in a way that you and I can better understand it). This is what he said:

“The resonator chambers primarily dampen several peaks in the treble range. To me, a peaky treble is most annoying when it makes the headphones lisp and the singers ‘s’ sounds become too sharp to enjoy the music. A second effect can be unnaturally aggressive percussion, but lisping is my litmus test for peaks, which varies from song to song. Sometimes the song itself is mastered too liberally in those frequencies, in these cases a revealing headphone should transport that as well.

The back volume…gives us complete control over the tuning, so we can worry about everything else when developing the earphone housing, the assembly process, etc.. For example if you just overdo it with the mids, the sound becomes closed-in, undynamic and generally unenjoyable for music listening. It gives us a lot of flexibility during development, but it also means outstanding quality control for the end user to get exactly the sound they listened to in a store.”

Whatever the IE 900 is doing or not doing, and regardless of whether or not what it’s doing suits your preferences, the one thing I think we can all agree on is that it’s been precision engineered by a company that knows a thing or two about tuning headphones. Sometimes the smallest innovations make the biggest difference, and this seems to be the case with the IE 900.

For more information on the various components, frequency response, THD and other technical aspects of the IE 900 design, you can download the full spec sheet from Sennheiser here.


Finish, fit and comfort

The IE 900 makes a change from the larger, bulkier, heavier multi-driver IEMs that have dominated the high-end and mainstream market for some time now. It’s a welcome throwback to more compact single-driver designs, and I applaud Sennheiser for sticking to their proven design aesthetic with the IE 900 rather than blindly following current trends.

The aluminium shells are well made, and feel refreshingly cool to the touch. They seem very resilient too, though I still wouldn’t want to drop them, and their fragile internals, from any sort of height.

I generally keep my IEMs permanently attached to their cable and stored inside a hard case or pouch, and the IE 900 is no exception. The included case is protective on the outside and softly lined on the inside, with ample room for the earpieces, cable, extra tips and even an extra cable if you need to carry one around with you. I normally like to prevent my earpieces from clinking against each other, so use a mesh case from Campfire Audio (product link here) for extra protection.

All of this contributes to what I consider to be one of the most comfortable IEMs I’ve had the pleasure of using. Comfort is a non-negotiable for me when it comes to the gear I use for several hours at a time, and the combination of small size, smooth finish and relatively shallow insert makes the IE 900 an easy recommendation in this regard.

That said, the ergonomics of the IE 900 don’t make for a seamless wearing experience for everyone. I’ve heard of several instances from very experienced IEM users I know and trust that have struggled to get a good fit with the IE900. For one, the earpieces are very light, and since they’re attached to the cable using MMCX connectors, they swivel (or helicopter) quite easily. The cable itself, while very smooth and supple, terminates in a memory wire-shaped hook that’s fairly thick, and somewhat bulkier and heavier than the IEMs themselves. If not seated properly, the cable and hook will simply yank them out of your ears with the slightest movement, especially if the tips don’t grip your ears like they should.

There’s an art to properly fitting the IE 900 that, once mastered, makes it quick and easy for me to slip them in every time. Hopefully this will help some of you who are still struggling with fit (with thanks to my wife, the ear model):

1. First, loosely flatten out the earhook, facing the cable entry forward (in front of you and away from your face). Don’t worry about shaping the earhook before inserting the earpiece. It’s going to deform anyway, so rather save your energy.
   
   
2. Grip the earpiece between your thumb, index and middle fingers to prevent it from swiveling around the MMXC connector, then gently insert the tips into your ear canal and corkscrew the earpieces counter clockwise while using your free hand to hook the cable around your ear. Don’t force them in, you just want enough pressure for a good seal. If pushing them in hurts your ears, or they’re going in too easily and not creating a seal, you’re either pushing too hard or the tips you’ve chosen are probably too small. Swap tipsand try again.
   
   
3. While holding the earpiece in place, use your free hand to gently pinch and mould the earhook around the top and back of your ear. Not too tight so that it clamps your ear, but tight enough so that it keeps the earpiece in place, with the rest of the cable falling away weightlessly.
   
   
4. If you’re still finding the earpieces aren’t perfectly seated, push the ‘bottom end’ of each earpiece (the part that goes into your ear) slightly forward (in other words, deeper into the ear). The earpieces will now sit at an angle, but should hold firm, albeit with a slightly deeper fit.

Now that you have the earpieces and cable in a comfortable position, no amount of head movement, jaw movement or light cable tugging should shift them out of place. Feel free to use both your hands to pat yourself on the back for passing the Advanced IE 900 Fitment Course with flying colours.

On cables and eartips

Before we move on to the substantive part of this review, a quick note on cables and eartips. Newcomers to the hobby sometimes get despondent when they crack open their IEMs only to find the cable sucks and the tips don’t fit as well as they should. As an experienced (read battle weary) IEM user, I almost expect to ‘roll’ the cables and tips of a new IEM to see if I can change the sound, fit, or both for the better. In fact, I’m now at the point where it’s rare that I even take the stock tips and cable out the box with most IEMs.

The IE 900 is slightly different in that the tips it comes with are rumoured to have some sonic characteristics important to the sound. According to Jermo, that’s not the case:

“The foam within the ear tips has been implemented solely to protect the transducer from cerumen or other ingresses. Foam is necessary to catch even small particles, but it’s also nearly impossible to prevent foam from building up some acoustic impedance if you compress it. If you look closely, the foam is very large-pored.

If we wanted an acoustic impact, we’d choose a finer, better-defined material. If the IE 900 were a relaxed earphone that might turn dull with a bit of impedance, [and] we would have chosen a different solution. But the IE 900 is a brilliant earphone and a slight change of 1-2 dB in the treble doesn’t change the character to the worse for most people. Long story short, you can use whichever ear tip fits.”

So, there you have it folks, from the man himself. Stop worrying about sonic filters and proprietary tips and tip roll the IE 900 to your heart’s content!

Fortunately, I have a war chest full of third-party tips I can choose from, so when none of the included IE 900 silicone tips sat comfortably in my ears, I was able to quickly find an alternative that fit better and (as I would later discover) sound better too. Do note that the stock tips have a clever two-slot system that allows you to position the tips further forward or back on the nozzle, for a deeper or shallower fit, and that you lose this feature by switching out to third-party tips without these slots.

As for the cable, I happen to quite like the stock cable, and the fact that you get a 4.4mm-terminated cable in the box is a big plus. Yes, the included cable is microphonic when you’re fiddling and fitting the IEMs in your ears (for the uninitiated, microphonics are the loud scraping sounds you hear when the cable rubs up against your sweater or skin as it dangles from your ears).

Thankfully this is not an issue once the earpieces are seated and I’m sitting down to listen, and if I get up to walk with the IEMs, the chin slider mostly prevents any errant sounds from the cable too. But, if you’re super sensitive about cable microphonics, get ready to roll.

I’ll compare various tips and the effect they have on the sound of the IE 900 later on in the review, but I’m glad to say the IE 900 may be one of the first IEMs I’m unlikely to cable roll for the foreseeable future.

Sound impressions

In my first impressions preview I went on a musical journey of discovery with the IE 900. Now that I’ve had a few solid weeks listening to it almost daily, I have a much firmer handle on what I’m hearing and will hopefully be able to describe it without resorting to images of rainbows and unicorns.

All listening was done with the stock cable and Acoustune AET07 tips, using a HiBy R8 DAP in high gain Turbo mode at a volume setting between 36 and 44/100. I’ve also included some notes on different tips and source matching.

Tonality

The IE 900 is a very balanced sounding IEM. There’s nothing in its tuning that jumps out and screams for attention at the expense of everything else. In this regard it’s not a wow tuning like you’d find with some specialist IEMs. Instead, the more I listen, the more I’m asking: ‘wow, why aren’t more IEMs tuned this way?’.

While it’s difficult to gauge how fatiguing (or not) an IEM will be after a few quick sessions, on the whole I found the IE 900 to have a fatigue-free, natural sound over the time I’ve used it. Tonally at least, I’m struggling to think of anything about the IE 900’s tuning that will fatigue even the most sensitive listener. It may not be to everyone’s preference in terms of aggression or in-your-face energy, for example, but fatiguing it simply is not.

I’ve seen the IE 900’s tuning described as V-shaped, but I don’t think that’s right. This is not an IEM that pushes excessive bass and treble energy and leaves the mids to dangle in the middle. I’m hearing a much more uniform U-shaped tuning, with a slightly lifted but otherwise linear bass, a very natural midrange that is neither too forward or too recessed, and treble with plenty of sparkle and air up top that pushes close to – but generally doesn’t cross – the brightness threshold to my ears.

All three strike a very cohesive – and importantly for a single-driver IEM – coherent balance. If there’s something prominent in the mix, you’ll hear it as prominent with the IE 900. If vocals are pushed back by the artist, they’ll stay pushed back. What you’ll get in return for this ‘hands-off’ tuning approach is exceptional quality, from the lowest sub-bass rumble to the tiniest flutter of high-frequency air. Like I said earlier, this is not a specialist IEM, it’s the consummate all-rounder.

One of the ‘tuning tricks’ the IE 900 seems to employ very successfully is a dip in the upper mids and lower treble (the so-called presence region) that lends a more relaxed tonality to the sound. It’s probably not so much a trick as it is a tuning choice, and is likely what gave me the initial impression of a laid-back listen. While I’ve since discovered the IE 900 is very capable of oomph when it’s called for, this laid-back quality is very much part of its DNA, and also what makes it so appealing to me personally (I’m not a fan of overtly aggressive transducers in any format).



Bass. The baseline measure of quality for any IEM, for me, is its bass response. With only one exception (Oriolus Traillii) I’m yet to hear any IEM that delivers perfectly natural sounding bass without dynamic drivers, and among the dynamic driver IEMs I’ve heard and own, the IE 900 is very close to the best. By ‘best’ I don’t necessarily mean fastest (it’s very fast for a dynamic driver though), or biggest (it’s plenty big, but there are bigger bass cannons out there).

By best I mean the IE 900’s bass is a delicious feast for any true bass lover. I find it very balanced between sub-bass and midbass, with a very deep sub-bass extension and healthy but not overdone midbass lift that adds just enough kick and punch.

Regardless of what’s playing, the bass seems to occupy a space just behind or just around other instruments and vocals, and as such remains distinct yet infused from and with the rest of the track. It’s a presentation that I’ve rarely heard with other IEMs, so I asked Jermo about it and he told me it has less to do with tuning than I assumed:

“It has not as much to do with tuning or design… for the most part, we’re standing on the shoulders of giants here. Producing the lowest distortion sound consistently and matching channels precisely in a single transducer gives you much of the more natural impression of space.”

I’m yet to find an example where the IE 900’s bass lets me down. Not one. From synth drums to real drums, bass guitar and classical bass, woofer rumble and kick drum kick. This is a masterful bass presentation that’s impeccably tuned. There’s zero midbass bleed, and even when the bass goes big, it somehow manages to occupy a space behind or around the vocals and supporting instruments without the usual cost to microdetails.




Midrange. While the IE 900’s bass is almost faultless, it also never pulls my attention away from the fundamentals of the music in the midrange. This speaks not only to the balance the IE 900 strikes with its tuning, but also to the natural voicing of the IEM.

The IE 900’s midrange is firmly in the Goldilocks zone for me: just wet and full enough (especially in the lower midrange), not too dry or thin, a very natural presentation in and of itself. It has an organic quality that makes me believe what I’m hearing, particularly with vocals, but also with physical instruments like guitars and piano. Male vocals reach deep with just the right amount of texture, and female vocals have a sweetness to them that I particularly enjoy without ever being too shouty (two things I definitely do not enjoy).

Listening to the IE 900 sometimes makes me feel like the recording disappears and the artist comes to life, sitting in the same room and singing directly to me. In fact, the IE 900 pulls off this disappearing act better than any other IEM I’ve heard (a mantle previously held by the 64 Audio U12t), and I attribute this mostly to the quality of its midrange.

When I think of midrange, I think of vocals, and since I primarily listen to female vocal-driven music, this is where most of my focus has been for this review. The IE 900 is a very human IEM, in that it renders both female and male vocals with an organic timbre that’s essentially lifelike. It’s something I keep coming back to but also something I feel needs to be emphasised, because so many IEMs that go for the spectacular fall short when it comes to lifelike vocals.

The IE 900 is like a warm blanket in this regard, not that its midrange tone is particularly warm – though it is warm in the sense that it sounds alive and full – but in the way it’s just instantly comfortable and relaxing at the same time, at least with the music I listen to.

And yes, I know that the fundamentals of most instruments also fall into the midrange bracket, but I’m far less attuned to ‘issues’ with instrumental midrange as I am to vocal delivery. That said, I’ve been very impressed by the realism (there’s that word again) of real instruments with the IE 900, though I’m probably not the right person to ask about instrumental accuracy, timbre and such.




Treble. Treble is probably the bottom rung on my list of tonal priorities. I only really notice the treble if it’s problematic (zingy and sibilant), or rolled off too soon (dull and lifeless). I’m fairly treble sensitive, so harsh treble that calls too much attention to itself is an instant fail, but I’m not as sensitive as I thought I was to a brighter tonality, as long as the treble is inoffensive.

The IE 900’s treble is fairly smooth and inoffensive, but not quite as relaxed as say a 64 Audio Nio or Legend X. Its treble tuning is such that the lower treble is fairly relaxed but the mid-to-upper treble can, on occasion, be strident, calling more attention to itself than I’d normally like. Some instruments, like cymbal crashes, can therefore seem more pronounced than they should be, at least compared to other instruments in a track, but this also lends itself to a liveliness and sparkle with most music.

According to Jermo, this is by design: “the treble of the IE 900 is at the upper end of what I consider pleasant and fatigue-free. We spent most of the development time dampening the upper frequencies to the level they are now and had several discussions about whether we need to go further.

The most common feedback I get now is if there is a way to increase the treble again. So in the end we have a common goal at the audiophile team: distortion-free and natural listening experience. On the journey to that goal, we have to make some compromises, i.e. If we want to have a strong response beyond 10 kHz, we may also have to increase the critical area of 5-10kHz slightly more than we’d wish for.”

I can probably count on one hand the number of tracks that irked me to the point of distraction over the past few weeks of listening almost exclusively to the IE 900. But yes, if I have to be critical, they’re there to be found. Whether it’s the faintly metallic tone in a small number of upper harmonic female vocals, or the peakiness of a wayward cymbal or misplaced piano strike, the IE 900’s treble, unlike its bass and to a lesser extent midrange, can be fallible with certain types of music.

A very (and I stress very) small number of female vocal recordings have also come close to sibilance, hitting a treble peak that can be uncomfortable for some, so if you’re fairly sensitive to this, an audition is probably a good idea before buying.

If I have to mark the IE 900 down on anything when it comes to tonality, its occasionally over-exuberant treble would be it. But then I’m actively seeking out issues for the sake of this review. Overall it’s still what I consider to be a very good treble response, given the single driver design that doesn’t have the benefit of multiple dedicated BA or e-stat treble drivers.




Technicalities

The IE 900 is a solid technical performer that doesn’t quite reach the lofty heights of multi-kilobuck, multi-driver IEMs at the very top of the tree (with pricetags to match). But, what it might ‘lack’ in technical excellence, it more than makes up for in one very important and often overlooked ‘measure’: musicality.

This is not an analytical microscope of an IEM I’d use to dissect the music, like Fourté , or a detail monster like Odin or Traillii. Instead, the IE 900 gives a good account of itself on every technical metric, even surpassing some far more expensive IEMs in some areas (as you’ll see below), but it’s less an IEM I’d pick on technical merit and more an IEM I’d pick for musical enjoyment.

Soundstage and imaging. Of all the technicalities us audiophiles typically like to compare, soundstage is my personal barometer in an IEM. While some people struggle to hear any ‘stage’ at all with IEMs, for me the very best IEMs are able to break down the typical in-my-head stage and trick my brain into believing the sound is much bigger than it actually is.

Some IEMs, like Fourté and Traillii, have earned a reputation for a particularly wide sound, with the tiniest of details easily audible at the extremities of the stage. While the IE 900’s stage doesn’t quite reach out as wide as those two, it’s still wider than what I’d call average, and much wider than what I’d call intimate. It also has fairly good depth and height for IEM stage (more depth than height), and with some music borders on holographic, with sounds being projected all around my head.

Closely related to stage, imaging defines how accurately (or not) an IEM positions different sounds on the stage relative to each other. For me, this is one of the real strengths of the IE 900, and part of what makes it sound so effortlessly lifelike in my opinion.

Another attribute of the IE 900’s stage is what I call ‘room feel’. Listening to the IE 900 is akin to listening to music with loudspeakers in a room. While you can’t really compare the sound of an IEM, even a great IEM, to speakers, the IE 900 is one of the few high-end IEMs I’ve heard (alongside Fourté and Legend X) that gives me a room feel sensation with some of my favourite music.

I think the best way I can describe the IE 900 soundstage and imaging characteristics is lifelike and natural, and if those words are already familiar to you, that’s because these are also the defining characteristics of the IE 900 for me.


Separation and layering. I never thought a single-driver IEM like the IE 900 would stand a chance against multi-driver IEMs when it comes to separation and layering of vocals and instruments, and technically speaking I was right. I don’t think the IE 900 has the same space and air between instruments and vocals as Fourté, for example, and is a rung or two below the Trailli when it comes to layering the different sounds in a track (but then again, most IEMs are a rung or two below Traillii in this regard).

That said, the IE 900 does not sound congested, even on busier tracks, and there’s more than enough air between and around instruments and vocals so they don’t trip over each other. I’ve already covered this aspect in some detail above, but vocals are particularly well separated from instruments, and the IE 900 somehow manages to render bass on a separate level to most other sounds while still sounding completely cohesive.


Details and clarity. I’ve already suggested that the IE 900 is not a detail monster like some of the better-known high-end multi-driver IEMs with their fancy e-stats and whatnot, but that’s not to say the IE 900 doesn’t do detail. It actually sits comfortably at the upper end of the detail scale for me, but unlike some IEMs that shove detail in your face for fun, the IE 900’s details are there to be enjoyed at leisure.

Overall clarity is also in the upper echelons, with vocal clarity particularly impressive. Even though I suffer from moderate hearing loss, and sometimes struggle to make out certain softly spoken words in a loud environment, I’m hearing vocals much more clearly with the IE 900 than I do with many other IEMs, even IEMs that supposedly have unnaturally elevated mids (which the IE 900 does not).


I didn’t expect the IE 900 to compete technically with some of the top dogs on the market, so I wasn’t prepared when I heard it doing just that. Listening to the IE 900 for the first time, and now even weeks later, I’m still struggling to comprehend just how it manages to pull off some of the things it does with its seemingly simple yet deceptively complex design. While it may not win every race from a purely technical perspective, it’s so far ahead musically than mostly everything else I’ve heard, price irrespective, that I question how much this actually matters.

Still, if you’re someone that favours technical performance above all else, I don’t think the IE 900 will let you down, even though I don’t consider it an IEM best suited to the analytical listener.



Select comparisons

Unfortunately I can’t compare the IE 900 to any IEMs in its price bracket and the only other single dynamic driver IEM I own is BLON’s BL-03, which costs less than the IE 900’s spare tips. My ‘other’ IEM is the legendary Empire Ears Legend X, and while I hear many similarities between the two, the Legend X has seven drivers and costs $1000 more than the IE 900, so it’s not exactly a level playing field.

Also, while I no longer own it, I did manage to briefly compare the IE 900 to 64 Audio’s Tia Fourté side-by-side, but at almost three times the price of the IE 900, it’s in a different category of IEM altogether. That said, if anyone owns or has heard any of these IEMs, the following notes could be useful.

BLON BL-03. Say what you like about one of the most hyped IEMs in the history of hyped IEMs, but when it comes to the BLON BL-03 (BLON for short), the hype is real. This has to be one of the best tuned IEMs for my personal preferences, with a spacious, punchy and tonally even sound that shames some kilobuck IEMs I’ve compared it to (I’m looking at you, Andromeda).

Compared to the IE 900, the tonality of the BLON doesn’t deviate too far from what I consider ideal. Both are U-shaped to my ears. There’s some sub-bass rolloff with more midbass energy in the BLON, but I still find the bass very clean and with just the right amount of oomph, though not nearly as clean or textured as the Sennheiser’s. The midrange of the two is similarly close, with the BLON exhibiting a little more upper mid energy, but not much, and both pull back in the presence region just enough to create a greater sense of space and prevent female vocals from getting shouty. The IE 900’s mids are significantly better defined and detailed however, while the BLON is prone to some smearing with less-than-ideal recordings. The two also share a similar treble trajectory, though the BLON is a touch more peaky and rolls off sooner, while the IE 900 can be more intense.

Where the IE 900 pulls away, in a big way, is technically, leaving the BLON to huff and puff while it sails through in every category. Both share a fairly large stage, relatively speaking, but the IE 900 is easily more expansive, wider, deeper and better defined, while the BLON is just naturally comfortable. The IE 900 images better, separates better, and its detail retrieval isn’t really fair by comparison. All that said, the BLON is still no slouch, and what it lacks in absolute technicalities it makes up for with a warm, smooth, full and easy listening sound, and is the only IEM I find even more comfortable than the IE 900 for all-day listens.

Empire Ears Legend X. Of all the IEMs I’ve owned and loved, none have matched my personal preferences more than Legend X. Widely considered to have the best bass in the business, the Legend X is actually a very balanced IEM, with an organic tonality ideal for just about any genre of music, and technicalities that sit firmly in TOTL flagship territory.

Compared to the IE 900, the Legend X – like the BLON – is not too dissimilar tonally. I hear the Legend X’s tuning as distinctly U-shaped rather than the more commonly suggested bass-dominated L-shaped curve. The Legend X definitely has more bass energy than the IE 900, but only if the track calls for it. It’s definitely more extended into the sub-bass region, with a healthy but linear midbass elevation that only gets back down to IE 900 levels around the 400Hz mark.

The IE 900’s midrange is slightly flatter and more balanced with its bass and treble, but the Legend X’s isn’t far behind. Where the Legend X improves on the IE 900’s midrange, in my opinion, is detail, being able to bring out slightly more subtle nuances without being too forward. It’s also wetter and more organic compared to the IE 900, but always clear and, to my ears anyway, never recessed. The Legend X doesn’t have quite the same treble energy as the IE 900 so makes for a smoother, slightly warmer listen overall, but still manages to outdo the IE 900 when it comes to treble detail.

Technically the Legend X improves on the IE 900 in every metric, from stage width to imaging, separation and detail. This is probably the part that surprises most people on first listen, combining an understated power and organic tonality with world-class technicalities and a balanced tuning, especially with the right (neutral) pairing and right (wide bore) tips. It may not have quite as much air or shine up top to satisfy the true treble heads, but then neither does the IE 900, and that’s just fine by me.

64 Audio Tia Fourté. This IEM probably needs no introduction, other than to say it’s one of the best and also one of the most polarising IEMs I know. With an eye-watering price of $3600 (which buys you a junk cable and a very average accessory selection), Fourté remains a technical marvel almost five years since it was first released.

Compared to the IE 900 – and BLON, and Legend X – Fourté couldn’t be more different. It has a bright-leaning U-shaped tuning that favours treble energy and clarity over midrange fluidity or bass impact. Until I heard the IE 900, Fourté was my ‘reference bass’ benchmark, with a full, impactful (when required) bass response that gives it an immensity of sound akin to full-size floorstanding speakers, though it never quite satisfied my big bass cravings. It’s not the fastest bass, but is so detailed and textured it’s almost palpable. That the IE 900 was able to match and exceed Fourté’s bass in both quality and quantity was the biggest surprise for me on hearing them together for the first time. The IE 900 also does a better job at projecting the bass coherently across and around the music, whereas Fourte’s bass is somewhat separate from the other frequencies.

Midrange is where the IE 900 eclipses the Fourté to my ears. I’m one of the few (and fortunate) to hear Fourté as fairly natural, but even I won’t pretend it’s anywhere near as natural or realistic as the IE 900, especially when it comes to vocals. The Fourté’s vocals are airy, lofty, slightly dry, and typically float around its massive stage projection, whereas the IE 900 is more grounded, lifelike, with a dead centre stereo image (when called for). A sharp dip at around 800Hz makes some male vocals slightly hollow with Fourté , and female vocals can sometimes err on the brighter side of comfortable, although the latter is more recording dependent than a flaw in Fourté’s tuning. Treble is where the two IEMs differ the most, with Fourté using its unrivalled treble extension to infuse the sound with air and detail, and doing so exceptionally well. The IE 900’s treble is still fairly energetic by comparison, but not quite as smooth or refined as Fourte’s.

Technicalities is where Fourté really flexes its muscles (and justifies its price tag). It has one of the widest, most holographic stages of any IEM ever made, combined with clinically precise imaging, masterful separation, and more detail than the human ear could possibly resolve. This isn’t always to Fourté ’s advantage, however. The IE 900 is far more forgiving of poor recordings, for example, and is also more consistently musical. The IE 900 is also more natural as a result of its slightly narrower stage, and to me sounds more lifelike too.



Odds and ends

The IE 900 is fairly source agnostic, which is to say it’s going to sound great from just about any source. While I normally only use it with HiBy’s flagship R8 DAP, with its detailed, balanced, and slightly warm-of-neutral reference tuning, I enjoy the IE 900 just as much from my LG V30+ smartphone (with its drier, brighter Sabre DAC delivery), and even, on occasion, with EarMen’s Sparrow (review here) and TR-Amp DAC/amps (review here).

Interestingly I find the IE 900 to be both easy to drive and very power hungry at the same time. With a 16-ohm impedance and a sensitivity of 123 dB (at 1 kHz and 1 Vrms), it should be very easy to drive, yet requires the longest turn of the volume dial of all my IEMs to get it to my comfortable listening volume. To me that suggests the IE 900 is scalable, and will probably take well to even more powerful desktop amplification, though I have no such amplification on hand to verify my suspicions. I can say for certain it’s not sensitive to the point of exhibiting any hiss whatsoever with the HiBy R8, even on full power, and the R8 is prone to hissing with overly sensitive IEMs.

Eartips, on the other hand, can and do affect the sound profile of the IE 900. As mentioned earlier in the review, the included tips are not required to filter the sound of the IE 900 or tame its treble in any way, so whatever you may have read to the contrary is incorrect. Out the box I didn’t like the fit or sound of the stock silicone eartips, and since I don’t enjoy using foamies, didn’t even try the stock foam tips for size. But I did try several different tips with the IE 900, each with its own quirks and qualities, so thought it might be useful to include some of my findings below.

Acoustune AET07 – this is my preferred tip for the IE 900, which I hear as clear and exceptionally detailed (especially in the midrange), with a powerful, almost visceral bass response that travels through the stiffer stem and tickles my ears across the super soft umbrella-like silicone. It also gives me the widest, deepest stage of all the tips I’ve paired with the IE 900. The 07 can be quite revealing though, so poorly recorded brighter tracks may have you reaching for one of the warmer tips below.

JVC Spiral Dot – this is easily the most comfortable tip, with its soft, pillow-like silicone and pliable stem. The IE 900’s nozzle lip (which really should be standard issue on all IEMs) ensures the tips don’t slip off in my ears like they do with most other IEMs, and there’s enough of a gap between the IEM nozzle and tip opening for the ‘dots’ to do their sonic magic – i.e. soften and shape the treble and accentuate the bass decay. Compared to the Acoustunes, Spiral Dots do indeed soften the sound, making vocals slightly more ethereal and ‘distant’, but also smoothening the treble peaks while retaining most of the bass impact. If you’re finding the IE 900’s treble a bit spiky for your liking, try on some Spiral Dot tips.

Sedna EarFit/Light Short – closer to the Acoustune sound but with more contrast between bass and treble, the Sednas are a great choice with the IE 900, if you find them comfortable. The harder silicone of the Sednas makes them more noticeable over longer listening sessions (and not in a good way), and while I still find them comfortable with the IE 900 compared to other IEMs I’ve used them with, the combination of harder sound and harder fit compared to the Acoustunes makes them only third best for me.

Spinfit CP500 – I got these tips more out of curiosity than anything else, since I’ve never really gelled with Spinfits for some reason. These are longer than the other three tips above, and even though they’re made of soft silicone and have the trademark Spinfit bend when inserted, I still find them less comfortable to wear for longer sessions. Sound-wise they have a softer bass response than the three tips above, but also a more balanced tuning, so if you think the IE 900 is too dynamic and powerful for your liking, the CP500 might tame them for you – assuming you manage to keep their very wide stems seated on the earpieces and not in your ears.



Closing thoughts

I still remember when, in my early days in the hobby, Sennheiser’s IE 800 – with its black ceramic shell and twin-turbine aesthetics – was an aspirational IEM for me. When I finally got to hear it for myself, I was won over by its warm, full sound, ample bass and great staging, but left disappointed by its permanently attached, jangly, single ended-only cable and less than ideal, bottom-ended fit.

The IE 900, if it is to be the IE 800/S successor, is a major and worthwhile upgrade in every way. From styling to build quality, sound quality and accessories, it takes pride of place as not only the best IEM Sennheiser has ever made, but in my opinion, the best headphone Sennheiser has ever made, bar none. It even eclipses the HD800 which, for me, is the pinnacle of dynamic driver headphone design.

Whether or not Sennheiser will continue raising the bar in headphone design under new ownership remains to be seen. What we do know is that, in the IE 900, they have created a flagship worthy of the brand, and worthy of the heritage. A single dynamic driver design that’s both effortlessly musical and technically excellent, without ever sacrificing the former for the latter like so many other flagships (and even some of their own headphones) tend to do.

Like any IEM, the IE 900 is not without its flaws. The flipside of its easy going tonality is a treble that pushes too close to overexuberant for my personal liking, though it’s only ever crossed that line once or twice with the music I regularly listen to. Other nit-picks I could point to would be the occasionally microphonic cable, odd tip selection, uncommon MMCX connector design, and occasionally unconventional fit.

All that said, the IE 900 is one of the only high-end IEMs that’s truly engaged me from the very first listen, not with the spectacular, but rather with its balanced, natural, lifelike and completely non-fatiguing presentation of the music I love. It’s an IEM that, more than most I’ve heard before, removes the artificiality of the recording chain and connects me directly to the music. I’m in the room with the singer, on stage with the band, in the studio with the mixer. I’m hearing real drums and real guitars and real voices in an utterly realistic space, and not for a minute is my attention drawn away from the experience.

Put it in your ears, hit play, and you quickly forget you’re listening to an IEM. It’s a human experience that has less to do with technology and more to do with the people behind it:

“I couldn’t devise an acoustic target that makes off-the-shelf transducers sound good enough that they practically disappear. It’s 90% the transducer technology and all the developers and engineers working for decades to make this performance possible.

The [real] stars for the IE 900 in particular are Grit Bonin, the acoustic engineer who implemented my target and requirements into the product, and Heinz Epping and Maike Faulhaber, who made world-class simulation efforts to optimise the last bit [of performance] of the transducer. Finally, André Michaelis, who initially headed the development of our 7mm transducer 16 years ago, and also convinced upper management to make a ten-digit investment to build the most advanced transducer assembly line in the world.”

The IE 900 is now the first IEM I reach for when I want to relax, want to connect, or want to explore new music for the first time, knowing I’ll be hearing it like it’s meant to be heard. It’s my miniature musical marvel, and comes with my highest possible recommendation.

I’d like to thank Vlad and @bogdan belonozhko for sending us a sample Radon 6 for this review, without any guidance or influence into how we’ll write it. Their enthusiasm for the community is infectious, and a big factor in FiR’s thriving popularity.

Introduction

FiR Audio’s Frontier series has been making headlines for all the right reasons for the past two years or so. With so much new technology and innovation crammed into the three founding Foundation members: Neon 4 (Ne4), Krypton 5 (Kr5) and Xenon 6 (Xe6 – reviewed here), the series is a breath of fresh in a golden age of high-end IEMs already pushing the technical and tuning boundaries.

Towards the end of 2022, FiR decided to pull a rabbit out of the hat – as they do – and announce an all-new, limited edition Frontier series IEM, Radon 6 (Rn6), to mark the company’s fifth anniversary milestone.

Following the periodic naming convention of its predecessors, Radon is based on the same driver configuration as Xenon, but with slight design modifications, all-new tuning philosophy, and a specially-crafted cable specifically matched for its sonic profile.

Interestingly, FiR decided to release Rn6 as a limited edition set, with only 333 units expected to be made, at the time of writing. Unlike the other Frontiers, there is also no official option for an Rn6 custom, although several customs were made and sold under special circumstances.

Whether or not FiR continues Rn6 production beyond the initial limited sets, or indeed includes customs as a standard option, remains to be seen. For now, what we have is an entirely new and, sonically, unique IEM that, to my ears, has the potential to outshine them all.



Packaging and presentation

If you’re familiar with the other Frontier series packing, Rn6 keeps things consistent. Presented in a matte black box with a wire diagram of the IEM on a pullout sleeve, Radon’s packaging is minimalist at best.

Inside you’ll find a firm foam tray with cutouts for the earpieces and pre-attached cable, a round leather carry case containing additional sets of eartips, a cleaning tool, the ATOM Xs tray and an ATOM Xs removal tool, along with an iron-on patch to proudly wear the Frontier brand outdoors.



Unlike Xenon, which is supplied with one set each of soft silicone and foam eartips, Radon includes a set of Symbio hybrid silicone/foam tips, along with a separate set of foam tips. I’ve never been a fan of Symbio tips, finding them too hard and uncomfortable to even notice their sonic benefits, so I suggest experimenting with tips for yourself to find the ones that work best for you.

This is also good place to mention how finicky the ATOM Xs modules are to install. While the miniature design must have its reasons, practically-speaking swapping modules can be a pain. That said, FiR produced a video showcasing how to remove and install the modules, and I must say it made the process much easier to understand and follow. I’ve included the video here for easy reference:



Another thing worth mentioning is that the paint on the included modules, especially the red module, tends to flake off quite easily, leaving reddish residue in the ATOM Xs slot on the IEMs. If this bothers you, contact FiR and they’ll send you a replacement set of anodized modules, along with a cleaning kit for excess residue. It’s good to know the company has been so responsive to user concerns about this ‘tiny’ issue.

Radon and Xenon

I’ll be going back and forth between Radon and Xenon in this review simply because they share so many similarities, at least on paper. As such, it might be a good idea to read my Xe6 review if only as a primer to some of the tech I’ll discuss here briefly, though not as thoroughly as I did in that review.

Rn6 is packed with the same technologies FiR created for the entire Frontier series, including its breakthrough Kinetic Bass port and driver, ATOM Xs venting, open acoustics, and RIGID system.

By way of recap:

Kinetic Bass uses an outward-facing dynamic driver beneath an open-vented port above the IEM nozzle to transmit low frequency sounds indirectly through the ear cartilage, in a process known as bone conduction. This allows the full spectrum of bass energy to pass through your ears in the same way that it does using full-size speakers, which makes the bass feel more immersive, extended and ‘real’. It’s fair to say that FiR’s Kinetic Bass is different to the bass presentation on any other IEM I’ve heard.



ATOM (Air Transferring Open Module) venting is a staple technology on most FiR IEMs, based on similar technology to 64 Audio’s APEX (and its predecessor, ADEL) pressure relief system. It’s a brilliant technology that balances the pressure from sound waves pounded into the ear canal, reducing listening fatigue and, more importantly, protecting your eardrums.

The other, often overlooked, benefit of ATOM venting is the ability to fine-tune the sound by switching modules. Each module provides a slightly different level of sound isolation, from 10dB (red), to 13dB (black), 15dB (silver) and 17dB (gold). The higher the isolation, the more perceptible the bass levels, and therefore the overall sound balance across the FR. This makes Frontier IEM’s ‘tunable’ to some degree, in addition to other tuning methods like eartips and cables.



Open Acoustics is the umbrella term used for three different sound technologies inside FiR Frontier IEMs: tubeless open-top balanced armature drivers, a sound reactor that helps shape the sound projected into the internal chamber, and a sound reflector that directs the sound from the high-frequency (treble) driver directly into the ear canal. All three are said to improve sound fidelity and give the Frontier series its distinctive sonic balance.

Lastly, RIGID is also an umbrella term given to the series of resilient design features built into the Frontiers. These include a robust 2-pin socket that’s rated at more than 1000 cable connections, and a snap-on removable mesh screen that catches dust and debris from entering the nozzle and damaging the drivers. It probably should also refer to the Frontiers’ metal shells that look and feel as if they can take a real beating without suffering long-term damage.



Looking closer at Radon’s design, the Kinetic Bass port is slightly smaller than Xenon’s, though the bone-conducting dynamic drivers inside are the same size and type, as far as I know. Radon ships with an extra, default, red ATOM module, which also happens to be the least isolating of the black, silver and gold modules included as standard in the box.

Aside from these two fundamental differences, the size and shape of the Radon shells is similar to that of Xenon, although Radon is cast from a lighter, anodized aluminium instead of Xenon’s gold-plated stainless steel.

As such Radon is much lighter, though both IEMs are relatively small and light to begin with, especially when you consider how much tech is crammed inside. Radon is also finished in a matte black coating with a glossy black and gold-specked faceplate, making it far less ‘blingy’ than the gold and deep-blue Xenon hues.



If you get a good fit with the other Frontiers, Radon will be no different. If anything, it might suit you better if you prefer your IEMs featherlight, and I personally prefer the matte texture in ear to any of the other Frontiers, and while the nozzles are on the thicker side, the fit is still among the best I’ve had with universal shells.

I also prefer Radon’s all-new soft and pliable PVC cable to Xenon’s braided and twisty Scorpio C. It feels smoother, less microphonic, and better made, with 2-pin connectors and a gold-plated 4.4mm balanced plug to match, and fits right in with Radon’s dark, understated design aesthetic. Unfortunately, FiR doesn’t sell the cable separately, as it would be a decent upgrade for the rest of the series.

Retailing at $3,299 – a full $600 less than Xenon – you’d expect Radon to compromise on some of its sonic internals. Instead, it’s virtually identical, sporing the same 10mm Kinetic Bass dynamic bass driver, two open BA midrange drivers, one open BA upper-midrange driver, one open BA treble driver (with sound reflector), and one electrostat ultra-high treble driver. Both Radon and Xenon are also rated at 28-ohm impedance, and are very easy to drive (sometimes too easy, in fact).

I’m not sure where the price discrepancy comes in, and as you’ll soon see, why the asking price doesn’t reflect Radon’s relative performance against its bolder brother. Could it be that in creating a slightly more accessible version, in both price and tuning, compared to the ‘out-there’ Xenon, FiR has somehow stumbled upon an even better version of its original flagship?



Sound impressions

I’ll be comparing Radon and Xenon in more detail in the next section, but to start, let’s focus on Radon on its own terms. All testing was done using a select number of lossless and hi-res tracks from my flac and DSD library, which are referenced below where appropriate. Sources used include iBasso’s DX300 MAX, HiBy’s RS8, and Sony’s WM1Z.

Tonally, Rn6 has a quintessentially balanced, W-shaped tonality to my ears that spotlights bass, mids and treble in (almost) equal measure. It does this without over-emphasising any one frequency, or pushing any frequency to the point of harshness.

This is a clear, engaging, but even-paced sound that doesn’t go for ‘wow’ and instead creates a lifelike reproduction of the music you’re listening to in a very natural way – given the proper upstream source and file quality, of course.

There is colour here for sure; it’s not gregariously warm or thick a-la Xe6, nor is it neutral to a fault like some reference IEMs. Personally, I hear it as somewhere in-between, but to me it’s closer to reference than overtly coloured, especially with the red module (more on this later).



Bass has the distinct, deep, weighty-yet-open sound I’ve come to expect from FiR’s Kinetic driver, only it’s more evenly balanced between sub-and-midbass frequencies compared to Xenon’s midbass focus.

Even with the least-isolating red module, bass has a visceral rumble with oodles of texture, delivered in a tight, controlled way with zero bleed into the mids – until you switch to the more isolating modules anyway.

The electronic kicks in Aes Dana’s Inks seem to extend almost endlessly deep, with a satisfying weight you can almost see. It’s a subwoofer-like presentation that I really enjoy, more so than the ‘though the floor’ feeling I get from Xenon’s looser, more midbassy tuning. The edges of the bass notes are better defined, and while decay is slightly quicker, it’s still very natural with a quintessentially dynamic driver physicality.

Switching to ‘real’ drums, and the kicks in the Eagles’ live rendition of Hotel California hit in a natural, if slightly subdued way, closer to neutral than how I’m used to hearing them with more bass-forward IEMs. The texture and decay are all there, but the weight doesn’t steal the focus from the other instruments. Kinetic bass in general seems to come from a ‘deeper’ place, as if I’m hearing it emanating from inside my ears compared to more conventional IEM bass.

What Radon bass definitely doesn’t lack is texture. The latter third of Lana Del Rey’s A&W is replete with a wavelike bassline that feels like ripples of bass spreading across the stage. It’s a glorious experience with this IEM, even better in how it stays in its own lane compared to the various instruments, effects and Lana’s sultry vocals on this track.



Midrange tuning is another distinct deviation from Xenon, with a more ‘correctly-neutral’ lower midrange and gradual rise to a perfectly-peaked mid-to-upper midrange gain.

This does wonders for vocal purity, and as mentioned above, Lana Del Rey sounds absolutely exceptional with Radon. I mean, Lana sounds exceptional on an AM radio, but with Radon it’s as if she’s seated in the same room singing her latest poetry-music to an audience of one.

Gentle tracks like ‘Kintsugi’, ‘Fingertips’, and ‘Paris, Texas’ from her latest LP, Did You Know There’s A Tunnel Under Ocean Blvd, where her soft, sweet vocals are overlaid on a simple arrangement of piano and strings (and the occasionally-delicious sub-bass rumble) are as seductive as they are lifelike.

Vocals of the male variety are also very well done on Radon. Mark Knopfler’s distinctive twang on Dire Strait’s Sultans of Swing is set in line with, if maybe just a touch behind, his iconic guitar. In contrast, Leonard Cohen’s chesty drawl in In My Secret Life feels like it comes alive with the help of Radon’s Kinetic bass, while Justin Hayward’s Forever Autumn, originally taken from Jeff Wayne’s War of the Worlds, sounds iconically angelic.

Instrument timbre is another positive feature of Rn6’s midrange balance. There’s some organic warmth in the mids, likely from the Kinetic bass, but it’s not a veil as it sometimes sounds with Xenon, rather an accent. Mids have a fullness to them that sounds natural, for want of a different word, neither too wet or too dry.

Transients are crisp and full, the plucks of Ottmar Liebert’s Spanish guitar in Barcelona Nights sounding three-dimensional, perfectly mixed in with the congas and shakers on that track. Benny Andersson’s piano solo version of I Let The Music Speak is likewise delightfully subtle and nuanced, with just the right amount of weight and sustain on the keys.



Treble, and specifically the transition from lower to upper treble, is quite similar on Rn6 and Xe6, but Radon sounds more emphasised because of its comparatively less elevated midbass and lower midrange. Treble notes are still very clean, without any harshness, sibilance or peaks that I can point to in any of my test tracks.

There’s a slight lower treble emphasis, which makes poorly-recorded and already-splashy tracks even more so, but if your library is more sedate like mine, you’re unlikely to ever find this an issue.

Max Richter’s haunting strings in On The Nature of Daylight have a sweetness to them that cuts through with just the right amount of crispness. Similarly, his rendition of Winter 1, a recomposed version of Vivaldi’s famous The Four Seasons, layers the different string sections with outstanding accuracy, from the gentle intro to the soaring crescendo.

Listening for both male (Def Leppard’s Love Bites) and female (Missy Higgins, Shark Fin Blues) sibilance returns none on both, which is to say Rn6 is perfectly smooth in this region without losing any definition or blunting any of the transients.

While I wouldn’t call Radon’s treble the most extended I’ve heard, I’m also not particularly picky on treble extension. There’s enough air for my liking, especially on ‘airy’ tracks like Ilan Bluestone’s Will We Remain.

If you listen to a lot of treble-laden music and love your V-shaped sound, Rn6 might come across as slightly sedate for your preferences, but if you like your treble to keep its head down and stay in line with the rest of the music, that’s exactly what you’ll get.



Technical performance is, in a word, excellent – but with a few caveats. While I hear Radon’s stage as wide and spacious, it does lack some depth, but only in comparison to some of the best soundstage performers in the business (see Sony IER-Z1R below).

Listening to Owl City’s The Saltwater Room, I don’t hear any congestion at all, and there’s no sense that layering is compromised either, it’s just that sounds tend to trail off quicker to the sides and don’t linger in the centre stage as long as I’ve heard them do with some other flagships.

Imaging is accurate, Pink Floyd’s multitude of clocks chiming just where they should in Time, and Al Di Meola’s wandering shakers in Traces of a Tear almost making my head turn from left to right and back again to follow them.

Radon also excels in extracting all the detail in a track, particularly in complex vocal deliveries. I love how I can hear the subtle inflections in Heidi Talbot’s sugary voice in Cathedrals, and the fleeting murmurs in Angel Olsen’s delicate rendition of Chance. It may not be as resolving as ‘detail monster’ IEMs with artificially boosted treble or two dozen BA drivers, but it doesn’t need to be to sound as close to lifelike as I’d ever want for my own ears.



Speed and dynamics, check and check. Like Xenon before it, FiR knows how to build a dynamic IEM, and while Radon may have toned down some of the explosive excitement of its gold-hued brother, it’s still a top-class performer when it comes to volume swings, as a casual listen to Hans Zimmer’s Mountains will show you.

Overall, I find it hard to find any real ‘flaws’ in Radon’s tonal or technical performance, unless you call its lack of extreme colour or naturally balanced tonality a flaw. This is much more a ‘yes’ IEM than it is a ‘wow’ IEM. You can point to any of the previous Frontiers and describe a quirky characteristic that makes them ‘stand out’ from the crowd, but with Rn6, it’s more a case of everything just sounds right, just the way it should.

ATOMic tuning

As with all Frontier IEMs, the sound impressions above are written with an asterisk that says ‘subject to change on short notice’. That’s because swapping ATOM modules subtly but audibly changes the sound profile, and Radon is no exception. Instead of rewriting the impressions in four different ways, however, I’ve summarised the main differences between modules and how I hear them below:

Red is the least isolating and also the module I used to write these impressions. I’ll therefore describe the other three modules relative to how I heard Radon with red.

Black increases bass elevation across the board, though still manages to separate sub-bass without bloating midbass. Tonally it’s still a W, though bass-heavy tracks are skewed left compasred to red. Radon also sounds warmer now, the mids getting more glow from the bass boost, and there’s slightly less air in the treble, possibly as a result of the fuller mids. If you’re willing to give up some clarity and the last mile of treble extension, and prefer your sound warmer overall, black could be worth a try.

Silver starts to shrink the stage too much for my liking, though the bass boost becomes more prominent. Upper mids start to recess as the focus shifts downwards, though treble is still clear and natural, with plenty of sparkle and crunch when required. I don’t feel the technical hit is worth the compromise, but if you’re into a more bassy sound, this could be your preference. At this point I feel there are other IEMs that do ‘more bass’ better, and you’re losing too many of Radon’s strengths for too little return.

Gold is my least favourite module, turning Radon into a ‘mini Xe6’ but with blunted technical performance by comparison. Everything from upper mids northward gets a pillowy smoothness from the boosted midbass, and stage shrinks further, making it an even more intimate presentation than Xenon’s. If you crave a ‘different’ sound and don’t own a Xenon, it could be fun to play with gold once in a while, but personally I’d leave it in the tray.



Select comparisons

Xenon 6 ($3,899). If you’ve read the entire review to this point, you’ll already have some idea of the similarities and differences between Rn6 and Xe6. Despite having the same driver configuration and a very similar design, Rn6 is more than just a ‘retuned Xe6’, standing on its own as a very mature IEM and, in my opinion, the most ‘complete’ of the Frontier series.

That said, the most obvious differences, aside from their looks, is indeed their tuning, with Xe6 having unapologetically boosted midbass-to-lower midrange shelf, a very unusual and quite unique tuning choice for a high-end flagship IEM. This made, and still makes, Xe6 an outlier in terms of its warm, thick, enveloping sound, mixed with superb upper midrange to treble tuning that ‘breaks through the veil’ to deliver a simultaneously rich but also clear and engaging sound.

Rn6, in contrast, drops midbass and lower mids back down to ‘normal’ levels, especially lower mids that are now neutral. Midbass is still elevated, but only just, putting more focus on the sub-bass frequencies, with the corresponding elevation in rumble and lower-bass texture quite apparent.

This tuning choice puts Radon’s sound profile much closer to what I consider natural and lifelike, while retaining some of the fullness and warmth from its Kinetic bass driver. It also opens up the upper midrange with more air and significantly more clarity and apparent resolution than I hear with Xe6, although I find the relatively more forward midrange shrinking stage depth slightly in comparison to Xenon, which sounds more holographic.

Where the changes are most obvious is in tracks where vocals are closely mixed with instruments, and that contain at least some level of bass emphasis. This represents a large portion of my indie pop/female vocal collection, and any session with Xenon straight after Radon makes vocals feel more congested, the air warmed up, and a thicker coat of bass applied to the entire presentation.



I find Xe6 works well for thinner-mastered rock and EDM/electronic music with sparse, sharp instrumentation and effects, where the bass drone doesn’t stifle the final mix and gives the entire presentation a warm, impactful and highly dynamic feeling. This makes Xe6 a specialist IEM for my use case, and a hit-or-miss depending on what I’m listening to. Rn6, by contrast, is exemplary with most if not all of my music library, and sounds fantastic even when I’m exploring new music genres outside my comfort zone.

While technical performance is at least on par, I do find Radon’s improved clarity and midrange resolve adds an uptick to how I perceive its technicalities. With slightly shorter but still natural decay, especially midbass, Rn6 is also faster, and handles complex music with more composure and finesse than Xenon, which can come off as congested in busier passages, especially when there’s lots of midbass and lower-mid information in the track.

Overall, I find these two fantastic IEMs very complementary, as long as you have music in your library that gels with Xe6’s distinct coloration and don’t mind dropping nearly four grand on a specialist driver. Radon is easily the safest recommendation if you’re buying blind, and to me is the pick of the four Frontiers for its overall versatility. Here’s hoping FiR makes it a permanent fixture.



Sony IER-Z1R ($1,799). It’s no secret that Sony’s IER-Z1R is my favourite IEM, and has been for well over a year now. It has the tuning, technical performance and overall gestalt that ticks every box on my preferences checklist, and I’m yet to hear an IEM at any price that matches Z1R’s unique combination of sonic qualities.

But before we get to the sound, there are some key physical differences to consider between these two flagships. Z1R is, for some reason, notoriously difficult to fit for many people. As someone with smaller ears and narrow ear canals who’s never struggled with the fit, I can’t quite understand why. But then I’ve used many IEMs that don’t get any fit complaints, and with much larger nozzles, that I can’t get into my ears at all. Even Radon, with its thicker nozzle, is on the border of comfortable, and puts more pressure on my ear canals than the Sony.

Driveability is also different. Rn6 is much easier to drive, with the dial set at 9-10am on the DX300 MAX on average, compared to the Sony sitting at 1-2PM, both with low gain. The Sony also scales up more with more power from the source, whereas Radon sounds the same even from low-power sources like Sony’s WM1Z.



Tonally, where Rn6 is a flatter W-shaped tuning, leaning more bass-left depending on the ATOM module used, Z1R has a distinct U-shaped tonality, with bass and treble projected more forward, but – and this is important – so are most female vocals. Despite its tuning profile, Z1R actually has less bass elevation than Rn6, even with the red module, and while Z1R is mostly sub-based focused, you’ll feel more visceral rumble with Rn6 too.

Z1R’s bass has a uniquely liquid quality that seems to flow across the stage, gently texturing the lower frequencies and adding to the subtle echoes and cues that create its cathedral-like tall, wide and very deep stage. Radon’s bass is more centred, and doesn’t resonate quite as deep.

In fact, Radon presents sounds on a flatter plane, with bass, mids and treble more or less even on the stage, whereas with most of the tracks I used to compare the two IEMs, Z1R will have vocals and/or bass or some other element closer to me, with some sounds panned hard left and right, and others trailing off into the distance. As such I find Z1R more immersive, moving elements back and forth towards me, whereas Radon pushes my listening position a few rows back and keeps most of the action in front of me on stage.

If you’re looking for absolute slam and impact, Radon has the upper hand, whereas Z1R is more ‘polite’. That’s not to say it can’t slam, it’s just that Radon’s Kinetic bass is more physical.

Conversely, Radon’s mids, especially female vocals, are more revealing, and even though both IEMs are tuned for clarity in the midrange (especially upper midrange), I find Z1R sweeter and more natural, and Radon slightly drier by comparison. That said, Radon is more ‘correct’ in its placement of male vocals, so if you listen to lots of male vocal music, it’s probably a safer alternative.



Up top, Z1R has a bit more energy in the lower treble, whereas Radon spreads its treble energy evenly, and has more mid-treble presence. Radon also has a touch more air, but Z1R is more sparkly and pristine, with some of the best treble sweetness I’ve heard with any IEM. Neither IEM overloads the upper treble, which is very much in line with my preferences.

Technically I find both IEMs to be very much on par. They trade blows as to which is more resolving, both being just about as resolving as I’d like with top-tier performance. Both are also very dynamic, Z1R maybe a fraction more, but it’s splitting hairs.

I do hear Z1R as having a slightly darker, quieter background, but only because Radon is a touch warmer. Imaging and separation are also fantastic on both, with Z1R possibly pipping Radon for first prize. Neither can match the clinical performance of dozen-driver IEMs, and both are also more enjoyable to me than any dozen driver IEMs I’ve heard.

Overall, as close as it gets, Radon isn’t going to replace Z1R for me, but because of its even-mannered profile, is better suited as a benchmark IEM that all others can be compared to.

Both fit my target IEM profile of top-tier all-rounder, and both have their own strengths that make them complementary. That’s more than I can say for most other high-end IEMs I’ve auditioned in the past year, Xe6 and Kr5 included.



A note on pairings

I was going to write a separate section on different pairings for Rn6, only to discover that Radon is incredibly adept at adapting itself to the sources I have at hand. Whether I’m listening to it with the DX300 MAX, RS8 or WM1Z, I’m not hearing significant differences in the sound.

The subtle character of each DAP comes through: RS8 with its smoother, analogue vocals, WM1Z with its gentler bass and lusher tonality, and DX300 MAX with its clean, neutral power. But overall, I can enjoy Rn6 from any of these sources without feeling like I’m missing out on quality, resolving power, stage size or tonal balance.

There are many IEMs, like Z1R for instance, that are pickier about which pairing they sound best with. Radon isn’t one of them, and that’s a good thing in my book.



Closing thoughts

I could sense Vlad Belonozhko’s quiet enthusiasm when we ‘met’ on a Zoom call earlier this year. We were discussing this very review you’re now reading, and I could tell that there was something about this IEM that was special to him, aside from the fact that it was a special edition commemorative of FiR’s success as a company.

Fast-forward a few months and I now share Vlad’s enthusiasm, if not more so. In my Xe6 review, I mentioned how that IEM had taken the industry by surprise, rising to the top of the popularity charts for those that own – or have owned – just about every high end portable audio driver on the planet. Rn6 is not that IEM…it’s better.

Perhaps unsurprisingly, Radon isn’t lighting up the charts quite like its older brother. It doesn’t have the same bold tuning, or bling looks, or aura of unapologetic bashfulness. It’s a safer, more polite, more correct-sounding IEM, but make no mistake, it still has that FiR Frontier flavour: unique bass physicality, exceptional technical ability and supreme build quality.



For me, Rn6 is the culmination of everything FiR has learned in creating the Frontier series, rolled into the consummate FiR IEM. It takes the clarity and speed of Kr5 and the power and technical performance of Xe6 bass and combines them into a new Frontier derivative that improves on both.

While I don’t believe the ‘perfect’ IEM exists, and that everyone has their own preferences, I honestly struggled to find fault with Rn6 with my own music library and preferences.

ATOM Xs is not the most user-friendly system, and there’s been some concern about the modules’ durability, but nothing that FiR hasn’t publicly addressed and rectified. I can also nitpick about nozzles, safe tuning, or even pricing to some degree, but none of these are anything I’d consider a showstopper.

The only temper to my enthusiasm for Rn6 is that more people won’t get to enjoy it, since production is capped. I’d also like to see a permanent CIEM option, which would optimise the sound further and remove any issues with fit.



I do wonder, though, if the decision to limit its numbers is the idea that an IEM that does so much right without blowing people’s minds is bound to find limited commercial success, especially at this summit-level price tier. I also get that, for this sort of money, people want an IEM with a party trick or two that nothing else can do.

However, if you’re someone like me who strives to get as close to lifelike sound reproduction with a sprinkling of fun and excitement, not many IEMs that I know of do that quite as well and quite so effortlessly as FiR’s new Frontier.

It’s an IEM that can easily stand on its own as a premium one-and-done for most audiophile enthusiasts, and for that, it earns my highest possible recommendation.

This review first appeared on The Headphone List

Preface: I was sent a review sample of the Meze Advar as part of the global Tour (thank you @Andykong). Prior to reviewing, I spent two days burning in the drivers, though didn’t make any notes on burn-in changes. I was also sent Meze’s 4.4mm balanced cable for Advar as part of the tour package, which is available separately for $149 direct from Meze. The opinions expressed in this review are entirely my own, based on my music library and preferences.


Introduction

Meze is a company that has always impressed me, first and foremost, with outstanding industrial design, build quality, and ergonomics. Founded in 2011 by Antonio Meze in the picturesque town of Baia Mare, Romania, the company came to prominence with the launch of the 99 Classics headphone in 2015. The Classics were starkly different from other mid-priced over-ear headphones at the time, with a striking wood-metal-and-leather design that turned heads, if not ears, to its exemplary craftsmanship.

Since then, Meze has released several iconic products, including its most recent Empyrean and Empyrean Elite headphones that occupy the high ground in headphone styling and comfort. Its smaller-format IEM products have made less of a splash, however. The 12 Classics is rather basic sound-wise but still elegantly made, while the Rai Penta ‘flagship’ received mixed reviews for its laid-back sound, but across-the-board admiration for class-leading build quality and comfort.

Enter Advar, Meze’s new IEM that, at $699, sits between the cheap $69 12 Classics and not-so-cheap $1099 Rai Penta. Unlike Rai Penta’s multi-driver design, Advar is based on a 10.2mm dual-vented dynamic driver, encased in a small, ergonomic stainless steel shell polished to a brilliant black finish, with a distinctive circular brass inlay that doubles as one of the bass vents.



Single driver designs seem to be enjoying a mini-revival in the higher-end IEM market, and, when well-made and tuned, bring with them the advantage of perfect sonic coherence, light weight, accurate timbre, and easy-on-the-ear ergonomics. The ‘downside’ is that they generally struggle to match the technical ability of higher-end multi-driver IEMs, which employ fast and precise BA, electrostat or planar drivers (and often a combination of these) to bolster an IEM’s ability to resolve more detail, achieve higher speed, or create a larger sense of stage.

Advar embraces all the single driver advantages I listed above, with technical ability that won’t be embarrassed alongside costlier multi-driver IEMs. It also features one of the most unique shell designs – with an exceedingly comfortable universal fit – that I’ve come to expect from the Meze standard. But before I prematurely start singing its praises, let's take a closer look at what you get, how I hear it, and let you be the judge.


Packaging and presentation

Advar ships in a black hardboard box, adorned with a gold foiled crest of what I presume to be a symbol from Romanian lore. Removing the slip cover reveals a black foiled version of the crest on the box lid. Inside, the first thing you’ll see is the Advar shells, inlaid into a velvet-lined foam block, like two pieces of fine onyx and brass jewelry.

Beneath the shells, Meze has included some quality accessories, though it’s not what I’d call a generous package. This includes a beautifully-printed high-gloss booklet with hi-res images of Advar and some words about Meze’s design philosophy; a superbly made and styled hard-shelled case with faux leather exterior and soft felt interior, with two mesh pockets for storage; a silver-plated copper single-ended (3.5mm) mmcx cable; a cleaning brush, a clever mmcx removal tool that actually works; and a selection of genuine Final E-type silicone tips.


I would have preferred to see a 4.4mm cable in the box, with either a single-ended adapter or a second single-ended cable as standard. While Meze’s balanced cable – which I got to test as part of the tour – is available for a not-too-hefty $149, neither cable is what I’d call premium, being rather thin, wiry, and prone to tangling.

This doesn’t quite fit with the darker styling and premium build of the IEMs, and ergonomically the weight of the stainless steel earpieces makes them feel unbalanced on the thinner cable, despite the moulded earhooks. I’d personally opt for a higher quality third-party cable in any case, not necessarily for better sonics, but definitely for better ergonomics.


Design and Fit

Make no mistake, Advar is as beautiful in hand as it photographs. The smooth steel fascias exude quality craftsmanship, as does the distinctive ‘horn-like’ inlay on each earpiece that reminds me of the aspirational Bowers & Wilkins Nautilus. In the ear, the small size and shallow brass nozzles make for an easy fit, the cool metal shells lending themselves to all-day wearing comfort.

This is not the warm, skin-like metal finish of Rai Penta, one of the most comfortable IEMs I’ve used to date, but after a solid three-hour session I don’t feel any discomfort from the tiny Advar shells. You may want to go one-up on your tip size, depending on the size of ear canals, in order to get a tight fit. As with any IEM – but with Advar in particular – a tight seal is crucial for optimal sound, without which the Advar might only appeal to those who love shrill, piercing highs.


As an aside, I don’t recommend the included Final E-type tips. While I managed to get a decent seal (I have small, narrow ear canals so that’s never a problem for me), I found the E-types played havoc with the midrange and lower treble, letting in too much air and spoiling the midrange balance. Therefore, all my impressions for this review were made using original Spiral Dot tips, which edged out Acoustune AET07 tips for comfort for me, and didn’t lose much to the Acoustunes for sound. I also tried my go-to Sony EP-EX11 tips, but found the treble too sizzly for my liking.

I tried a quick cable swap too, but found little to encourage further rolling from a sound perspective. Regardless of the cable you choose, I suggest you take your time tip rolling extensively, especially if you find Advar’s treble too forward or harsh at first listen.


Sound Impressions

For an IEM with a fairly sizeable dynamic driver, I found Advar’s overall tuning very balanced. Tonally it’s a slight W-shape to my ears, with bass elevated above neutral (but only slightly), mids – especially upper mids – crisp and clear, and treble confidently forward, detailed and airy, but also smooth and natural. This is not a warm tuning, but it’s not overly bright either. The crystalline treble and articulate bass lend themselves to hours of fatigue-free listening, and I’m yet to hear any hint of sibilance – other than when I wore the ‘wrong’ tips.

Bass. Controlled yet powerful is how I’d describe Advar’s slightly north-of-neutral bass delivery. You can tell there’s a proper dynamic driver inside that steely shell, with a good sense of rumble and weight where the music calls for it, and a neatly-struck balance between sub- and midbass.

The big drum salvo in Heidi Talbot’s Cathedrals fills the space with heft and commendable texture, without ever drowning Heidi’s delicate vocals. Sub-bass reaches deep in James Blake’s Limit To Your Love, though it doesn’t quite rattle the skull like some subwoofer-style IEMs, while at the other end of the bass spectrum, the kick drums in the Eagles’ live performance of Hotel California have all the hallmarks of a really well-tuned bass driver behind them.

Overall, I wouldn’t qualify this as basshead bass, but it’s a satisfying bass nonetheless. It doesn’t add much warmth, nor does it add fullness to the notes. Still, it’s cohesive and detailed, with a natural decay that makes bass-driven tracks thoroughly enjoyable.


Midrange. Lower mids are fairly neutral, male vocals coming across neither overly full nor forward or recessed in any way. This lends itself to the more neutral-leaning tuning, but also makes way for some of the most open and revealing upper mids I’ve heard lately. This is not a forward upper-mid tuning either, but the way vocals (particularly female vocals) tend to sit in front of, or at least level with, most instruments, without ever being shouty or sibilant, is quite an achievement. Those looking for strident upper mids won’t find them here, but I don’t find them lacking either.

If the mids lack anything, it’s probably vocal resolution (I’ll get to that shortly), but it’s not as if Advar is unresolving. Rather, it’s tuned for smoothness over ultimate detail retrieval, and if I had to pick a preference, that’s what I’d go for. It’s also not the fullest sounding IEM I’ve heard, and goes for clarity over warmth. It’s not dry to the point of being sterile, but it’s not what I’d call an overly organic sound either.

Alanis Morisette’s distinctive vocals on Uninvited are delivered with a smoothness I don’t often hear on this powerful track, as is Missy Higgins’ crisp, sibilant-prone voice in Shark Fin Blues. Some would say both tracks are a touch too smooth, even, but I’m hearing enough nuance and clarity to make them stand out from the mix, and I much prefer this type of laid-back presentation to a mid-forward, high-energy sound. I also like how male vocals are presented distinctly and don’t get lost in bass-driven tracks like Peter Gabriel’s Grieve. The same goes for busier tracks like Richard Marx’s Hazard, with his voice rising above the punchy bassline and ever-present tambourine treble.

Overall, there’s much to like in Advar’s midrange delivery. On some tracks, like Ocie Elliott’s Slow Tide, I even hear it as slightly mid-centric, without having to resort to muted bass or stunted treble as is the case with some other mid-centric IEMs I’ve heard of late.


Treble. This is where impressions might swing wildly, depending on the tips you use. If I couldn’t tip-roll beyond the stock E-Type tips and the Sony EP-EX11s, I’d swear the Advar’s treble was way too hot and sizzly for my liking.

Thankfully, using Spiral Dot and Acoustune tips saved the day, and I have to say Advar’s treble is now one of beauty to my ears. It has the ability to highlight the small, shiny sounds and effects in most tracks, the ripples off guitar strings, and pings of bells and chimes, and almost render them on a separate layer to other sounds. It gives the music a sense of crystalline clarity, with just enough air between vocals and instruments, and plenty of sparkle without ever crossing the line to sibilance.

The medieval flutes and bells in Angels of Venice’s Trotto are pristinely rendered, as are the stick instruments and shakers throughout this lively instrumental track. The striking highlights of the clocks in Pink Floyd’s famous intro to Time are also perfectly pitched without ever getting too spiky, and the strings of Max Richter’s orchestra in his recomposed version of Vivaldi’s Winter 1 are spritely, lively, and lightning-quick, without ever getting too pitchy.

If anything, I’d say Advar’s treble, once tempered with the right tips, could even be a touch too smooth for some listeners, especially those who want extra energy and crunch from their guitars and cymbal crashes. Then again, they can probably get that with a tip swap, although I think the added quantity won’t come with a corresponding jump in quality.


Stage, to my ears, is above average in all dimensions. It’s not quite as wide and cavernous as some, but I never felt the stage dimensions holding me back or presenting a track more intimately than I’m used to hearing it. Meiko’s Crush, masterfully recorded with a binaural microphone, is presented with a wide, deep sense of stage. It’s not what I’d call holographic, but rather more cohesive and realistic.

Layering and separation are excellent, some of the best I’ve heard from a single dynamic driver. The wide, deep stage lends itself to instruments and vocals occupying their distinct space, and that’s exactly what I hear, on the whole. Midge Ure’s 80s classic, Dear God, is replete with echoes and shimmers, all of which find their own niche on the stage. I’ve always wondered how that’s even possible with a single driver, but Advar is an example of how it’s not only possible, but when done well, can be quite mesmerising too. Imaging on this track is also very good, though in this case, not quite as accurate as you’d expect from a higher-end multi-driver IEM.

Resolution is the one aspect I wouldn’t rate as outstanding. While I still consider Advar a fairly resolving IEM, it’s not really digging into all the details I know are present in some vocal performances, Whitehorse’s Dear Irony and Angel Olsen’s Chance being two that come to mind. It’s only apparent when you know there to be more to a track than you’re hearing, and I mostly notice this in vocals rather than instruments, but if you want the last word in resolving power this isn’t it.

That said, I don’t think Advar is meant to be a detail monster, and I consider the smoother, more relaxed tuning one of its strengths. If you’re looking for a more contrasty, powerful sound, with wild macrodynamic swings, this probably isn’t it.


Select Comparisons and Pairings

I don’t have many other IEMs on hand to draw meaningful AB comparisons, but I can give you a general idea of where I feel Advar sits on the spectrum compared to IEMs I’ve used before.

For starters, I do have a BLON BL-03 that I keep around just because it’s too good not to. For you BLON fans out there, Advar is unquestionably the better-made IEM, with a more secure fit and significantly higher quality accessories. The BLON has one of my favourite tunings of any IEM at any price, however, which is to say it’s slightly warmer than Advar, with fuller notes and bass that hits harder and bigger too. Advar eclipses the BLON technically: it’s more resolving, more nuanced, and the sound is generally a step up in most metrics and overall quality. Both are excellent all-rounders, and if you’re willing to pair the BLON with better tips and a proper cable, it’s an easy recommendation for not a lot of money.

While I no longer have it with me, Sennheiser’s IE 900 is (and remains) my top pick for a single dynamic driver IEM. It has a similarly open, clear sound to Advar, but ups the bass quality by a notch or two, and is overall more resolving and refined. Advar by comparison is more evenly balanced, without the IE 900’s upper midrange dip and lower treble peaks that prove problematic to some (not me). Vocals are clearer and more forward with Advar, but IE 900 is more dynamic, with a bigger, more life-like sound. IE 900 also ships with better cables (two balanced cables as standard), and a wider selection of tips, and isn’t quite as tip sensitive as Advar for getting great sound out the box. Both IEMs are small enough with shorter nozzles that ‘disappear’ in my ears, with IE 900 just edging Advar for all-day comfort.

At the time of writing, I’m still waiting for my review sample of the newer Sennheiser IE 600, which sound-wise and price-wise should be more directly comparable to Advar.


Advar is a fairly transparent IEM, and though it doesn’t need much power at all given its easy-to-drive 111dB/31-ohm sensitivity, it still scales upward with source quality.

My favourite pairing was with HiBy’s RS6 R-2R DAP. It has a warmer, fuller tonality that works well with Advar’s slightly cooler tuning. Vocals are clear and natural, with a punchy, extended bass and smooth, crystal-clear treble. This is also the most balanced-sounding pair-up I tried, with no frequency over-dominating, and the technical level of both DAP and IEM are neatly matched.


A small step down from the RS6 in terms of preference – though not quality or power – is iFi’s xDSD Gryphon. Retailing for around the same price as Advar, this would be my pick if you don’t need a DAP, and prefer to keep tonality fairly neutral and revealing. While Gryphon gives you the option of adding some punch (xBass II) and air (xSpace) to Advar’s sound, I generally didn’t find myself using either. Treble is slightly thinner compared to RS6, and vocals are less full, but detail and extension are improved, so if you’re more of a technical listener, this pairing works better.

I also tried Advar briefly with iFi’s GO Blu dongle (using a wired connection to my LG V60 phone), and direct from the LG too, and while both had more than enough power, I didn’t find the overall sound balance satisfying with the smartphone only. I’d definitely recommend adding the GO Blu over listening directly from a phone, if only for the jump in refinement in sound (and my general dislike for the ESS Sabre DAC in the V60).


Closing Thoughts

Whenever Meze announce a new product, you just know it’s going to be a work of art. Advar continues the Romanian company’s tradition of creating uniquely styled and impeccably-crafted ear jewelry that satisfies beyond the listening.

There’s something both exciting and rewarding in owning a beautifully-made IEM like Advar. Importantly, though, I feel in Advar, Meze has finally realised the potential of its ‘house sound’ – which is as easy on the ear as it is on the eye – without compromising technical performance.

Advar, to me, is the most accomplished Meze IEM to date. As long as you’re willing to tip roll, it has a balanced, clear sound, with more than enough power in the bass, refinement in the mids, and sparkle in the treble to suit almost any genre without ever sounding harsh, sibilant or dull. It also has all the benefits of a single driver design, with fast, coherent sound, and a wider, deeper stage than other IEMs I’ve heard – especially in its price bracket.


For some reason, Meze is stubbornly consistent with its omission of a balanced cable as part of the stock package, and even its balanced cable is nowhere near as nice as similarly-priced but far better-made, more robust options from the likes of Effect Audio and PW Audio. But that aside, it’s a small price to pay for an IEM that, to me, is easily the flagship of the range, at least in terms of performance.

It may not be as technically advanced as more expensive options from Sennheiser, and doesn’t quite hit the level of the best multi-driver IEMs, but that’s comparing apples and oranges really. For the cost of entry, it sits alongside the IE 900 as my current top pick for a single dynamic driver IEM, and is big step up from the likes of Sennheiser’s IE 300 and Oriolus Isabellae.

There are few IEMs that can compete with Advar’s combination of world-class design, ergonomics and build quality, rivalling some of the very best multi-kilobuck IEMs in look, feel, finish, and comfort. I highly recommend Meze’s Advar to anyone looking for a well-priced, balanced-sounding, easygoing all-rounder of the highest order.

Full disclosure: Empire Ears sent me an EVO sample in exchange for a full and honest review. It’s not mine to keep, and if I want it, I need to buy it, like everyone else. The views and opinions expressed herein are entirely my own.

Also: The review features an exclusive Q&A with @Jack Vang about the motivation, challenges, and design of EVO, so you can enjoy some insights direct from the source. I’ve included Jack’s comments as ‘spoilers’ throughout the review, so you can choose to read it with or without his input.


First, some context

Basshead.

It’s a loaded word that, in the not-too-distant past, was used to distinguish ‘purist’ audiophiles from those who enjoyed blood and thunder with their music. IEMs with boosted bass were generally relegated to cheaper models, and the higher up the ladder one climbed, the more reigned in the bass seemed to be. If you wanted bass, went the saying, get a pair of Beats.

But then, one fine day in 2017, Jack and Dean Vang and their Empire Ears crew unleashed an IEM so confounding, so contrary to the norm, that it literally turned heads and had audiophiles of every ilk giggling like schoolgirls caught in a lie. Legend X, a derivative of Empire’s previous Legend lineage, almost singlehandedly upended the commonly-held notion that big bass had no place in civilized audiophile company.

It became, quite literally, a legend in name and reputation, and still holds sway today as one of the very best ways for serious audiophiles to have their bass fix and eat their Diana Krall/Eagles/Vivaldi cake too.

Still, despite the inclusion of higher-end technicalities and sophisticated tuning, Legend X wasn’t for everyone. Out the box with stock tips and cable, it was unashamedly a big bass sound first, refined listen somewhat distant second.

Over time, audiophiles started to find ways to fine-tune Legend X to their liking. They discovered it was very amenable to tip and cable rolling, and combined with neutral sources and some healthy burn-in time, it delivered a more balanced sound with bass still very much the foundation, but with its inherent technical strengths brought to the fore – like excellent resolution, a comfortably-wide soundstage, and a more open midrange.

Legend X was usurped as Empire Ears’ flagship long before the current flagship, Odin, was unveiled at the height of the 2020 pandemic, but even then, Dean and his team were quietly working on a new IEM that would take the very best of the technically-gifted Odin, and marry it with the raw power and sex appeal of Legend X. It’s an evolution of everything that the X began, matured and transformed, and appropriately called Legend EVO.



Introducing EVO

The headline feature that separates EVO from every other Empire Ears IEM before it is the all-new Weapon X full-range (5 – 35Hz) bone conduction driver. Using Japanese-made materials and a strong neodymium magnet, coupled with anti-resonance technology that minimises vibration diffusion, Weapon X affects and enhances EVO’s sound in different ways, from adding impact and physical vibration to the sub-bass response, to padding the air and volume in midrange notes and infusing a tweeter-like physicality in the highs.

This is a very different take on bone conduction than we’ve seen in other IEMs, with the main vibration channel working through a dedicated solid bore that connects Weapon X to the nozzle tip. It also means foam tips and very soft silicone won’t be as effective as solid core silicone tips for the bone conduction effect, something to keep in mind when pairing tips with EVO.


Weapon X is not the only new addition to EVO’s internals. The two Weapon IX woofers that made Legend X famous have been upgraded with the new Weapon IX+ drivers first seen in Odin, only this time they’ve been allowed to deliver their full, unbridled power, rather than tuned to neutral as in Odin. The same five custom-made BA drivers used for the midrange and treble frequencies have also been included, but re-tuned for EVO. Lastly, EVO sports an all-new nine-way proprietary synX crossover circuit that was designed specifically to work with Weapon X’s full range frequency extension in EVO’s Dual Conduction design.

Also present is Empire’s Anti Resonance Compound (A.R.C) coating that’s meant to eliminate internal resonances from those giant woofers inside the confined IEM shell. Build quality, as always, is top shelf, with the same seamless shell molding that makes Empire’s IEMs lightweight, comfortable, and highly resistant to shocks, though I’m still always ultra-careful bordering on pedantic when handling resin shells.

Presentation, design and fit

If you’re familiar with any of Empire Ears’ latest releases, from their ‘entry level’ Bravado Mk II to the aforementioned flag-bearers, then you’ll also be familiar with the attention to detail that goes into the retail packaging and presentation of these IEMs. EVO eschews some of the fancier elements – like the pull-out tray – and downsizes the box too, making it less bulky but also more environmentally friendly, while retaining the same solid appeal and obvious brand identity.

Gone is the magnetic foldover, replaced by a sturdy lid that lifts off to reveal some branded documentation and, beneath it, Empire’s exceptionally solid Pandora storage case, emblazoned with the all-new EVO logo. The first tranche of EVO preorders will receive, in place of Pandora, a custom Vishnu Leather case of similar dimensions, which may or may not be preferable, depending on your penchant for leather or metal.

Also breaking from tradition, EVO’s earpieces are no longer displayed in foam cut-outs and are instead shipped inside a small mesh pouch – separated down the middle to keep the earpieces from rubbing against each other – inside the case. Mine were sent already attached to the cable, so I assume retail versions ship with the cable pre-attached too – unless yours was shipped sans cable due to some unforeseen production issues at the time of launch.

On first removing the earpieces from their bubble wrap pouch (I didn’t get the mesh pouch with my review unit), I was struck by how similar-but-different they looked to Legend X. Made of solid resin, the shells are mostly opaque, polished to a brilliant piano black finish and coated with clear lacquer resin. EVO is notably bigger and bulkier than Legend X, but also translucent in parts, giving you a clear view of the Weapon X drivers when the light hits the shells just right. The left shell features the new EVO logo – and did I mention how much I like the new EVO logo? – while the right features the same Empire Ears ‘Wings’ logo that adorns recent Legend X iterations.


Size-wise they remind me of the new Bravado shells, only bigger, with slightly longer and thinner nozzles than Legend X. My main concern, prior to receiving EVO, was that the nozzle would be too long and thick for my smaller ears and canal openings. I personally dislike deep-insert IEMs, so it was with some trepidation that I picked the smallest-size Final E-type stock tips and, after saying a little prayer, carefully fitted EVO for the first time. To my surprise, the smallest tips were too small, and moving up a size allowed me to get a good seal – denoted by the customary ‘pop-pop’ of the Weapon IX+ driver flex – with a fairly shallow and reasonably comfortable fit.

Despite the better-than-expected fit, these are not the move around, walk outside, use for gym-type IEMs, at least not for me. Even with comfortable tips I still get some pressure, after a while, just inside my ear canal, and if I don’t tilt the earpieces just right, I can feel them pressing against the sensitive parts of my outer ear. You could argue this means the fit isn’t perfect, and I agree; they require careful positioning to seat just right. They’re large, cumbersome, and there’s no getting away from the feeling of having two large, intrusive objects stuffed in your ears, at least initially, and that feeling does go away after a while.

That said, they’re comfortable enough for how I use them, seated or lying down, on a couch or in bed, taking in an hour or two of quality listening. If you’re anything like me, they won’t work for all-day listening, but then few IEMs do. If, on the other hand, you’re blessed with big ears and even bigger earholes, EVO should fit you just fine, and so, like everything else in this hobby, YMMV.

One other thing to note is that EVO sports dual tri-port vents, unlike Odin and Legend X’s single port, likely to accommodate the new Weapon X driver, or possibly because twin Weapon IX+ drivers pushing air at full tilt need more pressure relief than previous designs. Regardless of the reason, the added port means slightly less isolation, though in practice EVO isolates extremely well, and I literally can’t hear anything else in my surroundings once the music starts playing. As far as I can tell, it doesn’t leak any sound either.


Cable and accessories

The new made-for-EVO Genesis cable (nice one guys…Genesis, EVOlution, get it?) is a 4-wire, 24-gauge, pure OCC copper cable by PW Audio. It features the typical PW Audio angled ear-hook design, which I’ve always found to be very natural, and appears to be a well-made higher-end cable in the same vein as PW Audio’s Anniversary-series cables. It also sports PW Audio’s updated matte-black Y-split hardware and chin slider, though the slider is irritatingly too big for the wire gauge and slides loose most of the time.

Dean clearly had a target tuning in mind when he picked Genesis for the EVO pairing, but it’s not my personal pick for EVO. Genesis is not in the same league as Odin’s Stormbreaker, which is based on PW Audio’s ‘The 1960s’ 2-wire/4-conductor design, or my custom-made @doctorjuggles Cardas copper cable for that matter – though I can only vouch for the sound and ergonomic improvements of the latter. It’s also slightly stiffer than I’d like, and the decorative blue core that’s visible through the translucent PVC jacket doesn’t quite gel with the EVO’s sleek black-and-gold colouring for me.

Still, it’s good enough, with a throaty, full-bodied sound that’s awash with detail, consistent with Peter Wong’s copper cable mastery. It’s also the first genuine Pentaconn-terminated Empire Ears cable, a welcome move that will surely be mirrored by all serious IEM manufacturers in the near future.


Along with Genesis, Empire Ears provides the same set of Final E-type black silicone tips in five different sizes, as I may have mentioned earlier, which again are not my personal pick for EVO. While comfortable enough, I’m not a fan of the Final E’s penchant for boosted bass with attenuated treble, as I feel EVO – even though it’s inherently more balanced-sounding than Legend X – sounds better with tighter bass and a tip that helps clarify and smooth out the upper mids and treble. For the record, I prefer Acoustune’s AET07 tips, which I also use with Legend X.

Regardless of how comfortable you are with tip and cable rolling, I strongly suggest trying out different tips and cables with EVO. I find EVO fairly sensitive to sonic changes, mainly with tips but also with cables, and if you’re not completely sold on the sound after a sufficient burn-in period (more on this below), switching up accessories could be the difference between good and great for your preferences.


Sound impressions

Unlike some reviewers, I don’t have access to a large number of different sources with which to test my IEMs, and I generally prefer a close-to-neutral source, which currently takes the form of HiBy’s flagship R8 DAP. As such all the impressions below are based on this pairing only, with the R8 set to high-gain Turbo mode, as it is for all my IEMs.

Keep this in mind if you’re using more coloured sources, because this can skew EVO’s sound significantly, based on my discussions with other enthusiasts. For a more comprehensive appraisal of different source pairings with EVO, check out the ‘Source Pair Up’ section of @twister6's outstanding EVO review here.

Another thing to keep in mind is that EVO is much easier to drive than Legend X, or the single-driver Sennheiser IE 900 for that matter. Despite being only 1dB more sensitive than Legend X on paper (103dB for EVO vs 102dB for Legend X), it takes a full 10 clicks on the dial to volume match the two. Moreover, I find EVO’s bass to be significantly more powerful, from sub-bass through midbass, at a much lower volume than it takes to achieve the same bass levels with Legend X, and with EVO also being a more dynamic and resolving listen, this makes it much easier to listen at lower volumes, not to mention safer too.

Lastly, my impressions allow for a 100-hour-plus burn-in period, and I wouldn’t recommend any proper assessment of EVO’s sound until you’ve put your EVO through a similar process. Without sparking the usual burn-in debate, I can say with confidence that EVO sounded very different out the box than it does today.

Initially, I found the bass was quite boxy and not very nuanced, almost too ‘big’ in fact, but within days it tightened up and became more precise, without losing any of its initial impact. I also heard some hardness or brittleness, for want of a better word, in more mid-forward tracks with very busy upper-mid/lower-treble sections, and this also settled after burn-in, continuing to settle even more after a few weeks’ regular use.

As a side note, you’d be well within your rights to suggest that a $3,000+ IEM should not have to be ‘seasoned’ like this to reach its best possible level, but this isn’t unique to EVO or Empire Ears IEMs, nor is it uncommon to most high-end, precision audio gear, especially gear with moving parts and/or dynamic drivers.


Tonality

While it probably makes more sense to compare and contrast EVO’s sound characteristics to its ‘predecessor’, I’ll leave that for the ‘Select Comparisons’ section below and instead focus on how I hear EVO on its own merits.

To my ears, from the very first post-burn-in listen, EVO shirks any suggestion that it’s a gung-ho L-shaped bass-heavy IEM. Instead, I’m hearing a very well-balanced W-shaped tonality, with some added oomph in the bass department only when it’s called for in a track. Even then, the way Dean tuned the mids – especially the upper mids – to generally follow the Harman target curve, means the added clarity and quality of EVO’s midrange is never overpowered by the bass.

With lower mids and upper treble slightly more relaxed, though still well within touching distance of the curve, and the transition from upper mids to treble being fairly gradual, there are no parts of the FR that sound unnatural to me. Upper mids are more forward than I’m used to, but I’ve come to appreciate how this plays into the overall tuning, allowing for listening at lower volume levels without any loss of detail, despite my moderate‘cookie bite’ hearing loss (worth a Google, if you’re curious).

Even for a non-musician like myself, I can tell that EVO has been tuned with instrumental accuracy in mind. The timbre of live instruments, especially drums and guitars, seems very realistic to me, and I’m also liking how EVO presents the attack, fundamentals, and decay of piano strikes right across the frequency spectrum. It’s not a dry, clinical tuning, but rather more lifelike, as I’d expect to hear these instruments played by actual musicians in person.


Bass is unquestionably the star of the EVO show, however. The same way you buy a performance car for its horsepower, you buy EVO for its bass. Yes, it has much more than just bass to offer, but there’s no reason not to flaunt your superpower when you have one. It’s difficult to describe EVO’s bass with one word, because it’s got not one, not two, but three different drivers contributing to a multi-faceted, multi-layered, almost multidimensional range of lower frequencies that are felt as much as heard.

EVO extends lower into the sub-bass region than any other IEM and virtually any other headphone I’ve heard before. At frequencies this low, sub-40Hz, the bass is more a feeling – a rumble – than an auditory experience. Before EVO I couldn’t imagine an IEM replicating the sensation of feeling the bass in my body, like a life-size subwoofer, and yet on several occasions, I’ve had similar sensations with EVO.

Take James Blake’s Limit To Your Love for a spin, and EVO might just leave you feeling a little seasick. From 0:55 both sets of Weapon IX+ woofers are activated simultaneously in a wavy, warbly sub-bass rhythm that's difficult to describe but oh so delicious to experience. I’m convinced there’s some bone conduction magic happening here too, since the intensity is so focused and also sandboxed in the sub-bass region, with almost no bleed into the upper bass and lower midrange.

Working through my checklist of sub-bass test tracks, EVO hits every low note with authority, from the door slam (0:13) in Rosie Thomas’s Why Waste More Time, to the ghostly rumble (0:59 and 1:07) in Kristin Hersh’s Your Ghost, and the repeating boom (from 2:21 onward) in Lana Del Rey’s Video Games. These brief moments add so much gravitas to each of these tracks that I can’t imagine them otherwise.

Moving further up the bass shelf, EVO doesn’t have a perceptible midbass ‘hump’ like many ‘bassy’ IEMs, and the curve dips gradually downwards towards the lower midrange, keeping midbass elevated, more so than other monitors but still very much in check. For me, this serves two purposes: to retain the maximum slam and punch in the bass when called for in instruments like kick drums, but also prevent the mid-to-upper bass notes from ‘veiling’ the detail in the midrange.

There are some great tracks I use to test out how ‘thick’ an IEM sounds as a result of its midbass emphasis. Ingrid Michaelson’s delicate vocals in The Way I Am can sound muffled when there’s too much midbass in the meaty upright bass plucks in the intro, which continues as a constant bassline throughout the track. With EVO the plucks are indeed weighty – and also perfectly textured – but stay well clear of the vocals when they start (0:17 onward). Likewise, Katie Melua’s indulgent bassline in Red Balloons sometimes obscures her vocal finery, but not with EVO.

Unlike many bass-boosted IEMs (like Legend X) that use special tuning tricks to keep elevated midbass from bleeding or bloating, EVO does it while retaining extremely healthy levels of bass quantity. With EVO it’s less a case of added midrange emphasis as it is sound shaping the bass.

The last thing I want to say about EVO’s bass is that, quantity aside, the quality is equally if not more impressive. This is not the slower, more elongated bass of the Legend X, or, the speaker-like but somewhat subdued bass of the Tia Fourte, or the hyper-realistic but ultimately less visceral bass of the IE 900. There’s a tactility and speed to the low notes that, to my ear, is a combination of very high resolution and precision. Then there’s the positionality (a combination of imaging and layering) that can only be achieved, it seems, with something other than traditional air conduction drivers, and so the combination of all three creates a bass presentation that, as far as I can tell, is unique to EVO and Empire Ears.

This isn’t limited to instrumental bass either; EVO makes EDM drops sound exceptionally clean, crisp and powerful, effortlessly keeping pace with even the fastest kick beats. Take DZP and Zanon’s hot single Indica,for example, featuring super-fast bass drops double timed with funk-like instrumental effects and exotic vocals. EVO can just as easily deliver skull-crushing bass on demand. A track like Groove Delight and Black Jacket’s Baiana, with some of the hardest-hitting drops I’ve heard (1:00 onward), makes EVO one of the most enjoyable EDM IEMs I’ve personally experienced.



Midrange is where things get interesting with EVO, and is perhaps its biggest tonal departure from Legend X. Empire Ears’ recent tunings have tended to introduce more upper midrange energy to the sound, most notably with Odin and, to a lesser extent, Hero. EVO follows a similar path, but in a less aggressive manner.

Before we get to the upper midrange minefield, however, a quick note about the lower mids, where most male vocals and the fundamentals of deeper female vocals tend to sit. On balance, EVO’s lower mids are maybe a hair below neutral, but there’s still enough residual energy from the upper bass, I feel, to impart male vocals with very natural if not overly chesty tonality.

Neil Diamond sounds very much like Neil Diamond in Hello Again, from the classic The Jazz Singersoundtrack. All the detail in his slightly coarse delivery on this track is there to be heard, with a hint of bass supporting his baritone, but it’s not the warm or coloured presentation that may be preferable to some. The same goes for Mark Kozelek’s brilliant supporting vocals in Holly Throsby’s What Do You Say, which I say sounds very natural indeed. I’ve heard him sound more weighty with other monitors, but I like how he sounds with EVO, and it’s probably more true-to-life too.

The upper midrange, as I’ve already hinted, is where things get interesting. Upper midrange/lower treble tuning – the so-called presence region of the graph – is an ongoing debate in audiophile circles. Some swear by boosted treble and recessed upper mids, a-la Tia Fourte and, to a lesser extent, IE 900, while others prefer boosted upper mids and/or upper treble to provide as much clarity, detail and air as possible.

EVO, for me, takes a measured approach. Yes, the upper midrange frequencies sit well above the lower mids, but the rise from lower to upper mids is more gradual than it is with Odin, for example. Beyond 5kHz, which is probably the upper limit of the upper midrange, EVO’s treble, which I’ll discuss in more detail below, doesn’t deviate sharply upward or downward, continuing the smooth transition from the midrange.

I therefore hear EVO, on the whole, as forward but smooth in this area, without any shout (in all but the poorest of female vocal recordings). It’s a midrange that’s neither too full nor too thin, too wet or too dry, but clear and full-bodied and definitely not sterile. This is tasteful colour, and when it works with the music, it works surprisingly well (for someone like me, who until recently was firmly in the recessed-is-best camp).

Norah Jones’s earthy vocals and accompanying instrumentation in Come Away With Me are so realistic, it’s as if I’m standing right next to her through the performance. There’s no hint of grain, glassiness, or sibilance in any of the tracks I use to test for them, including Katie Pruitt’s It’s Always Been You, Brandi Carlile’s The Story, BEYRIES’ Alone, Lana Del Rey’s Dark But Just A Game or Maggie Rogers’ Satellite. By the way, if you haven’t heard this last track, do yourself a favour and check it out, keeping in mind she recorded it as a teen with her high school band in a high school music studio.

While I do hear some added emphasis in the higher pitches of some female vocals on specific tracks, like Stevie Nicks in Fleetwood Mac’s Dreams, they’re never shouty – unless there’s shout in the recording. Vocals are also less forward than they are with some midrange-focused monitors, like Isabellae and, to a lesser extent, Traillii, but are so detailed that any hint of recession is overcome by the clarity.

It’s not all rainbows and roses, however. Out the box, one of the few issues I had with EVO was a brittleness or hardness in the presence region that I couldn’t quite put my finger on. It only cropped up on certain tracks, and then only in very specific sections of those tracks. Def Leppard’s Love Bites was one of those tracks, and I say was because, post burn-in, the roughness I initially heard in the parts where the melee of snare drums, grinding electric guitars and Joe Elliott’s pitchy vocals (1:20 – 1:30) was less confronting.

Still, there’s a vibrancy and energy when instruments and vocals get wild and heavy in this FR range that’s palpable, and potentially more fatiguing, than they would be with sedate monitors. Some extreme examples include the crescendo to Jillette Johnson’s Love Is Blind (2:08 – 2:16), and one I picked from the forums, Seven Lions/Wooli/Trivecta’s Island (featuring Nevve), where the combination of compression, bright vocals, and intense electronic instruments (especially from 1:48 onward) sounds like a wall of razorblades on EVO, especially at higher volumes.

My personal view is that, extreme examples aside, there’s an intimacy and immediacy to EVO’s midrange – a tuning choice from what I understand – that works well for the vast majority of my music library, but on occasion shows up the lemons in the mix. Why that is exactly, I’m not sure.

What I am sure of is that EVO is less forgiving than Legend X, or IE 900, or any other number of IEMs with a ‘safer’ tuning. EVO’s midrange, like its bass, is highly resolving, not far off from the most resolving IEMs I’ve been privileged enough to hear, like Fourte and Traillii. The added dimensionality of the bone conduction driver also can’t be understated, often presenting music or specific sounds in surprising and unfamiliar ways, and it could well be this unfamiliarity that jars, at least at first.


Treble, thankfully, is far from jarring. I could probably stop right there, because unlike its bass or midrange, EVO’s treble is rather inconspicuous. That’s not to say there’s a deficiency here, at least not for my personal preferences. I hear EVO’s treble as smooth, natural and polite, supporting rather than headlining.

There’s no lack of sharpness or detail to Nils Lofgren’s exceptionally trebly guitar play in Keith Don’t Go, or Max Richter’s cacophony of violins in his recomposed version of Vivaldi’s Winter 1. What it does lack is peakiness, harshness or mid-treble zing, preferable, in my opinion, to Legend X (occasionally peaky), Tia Trio (occasionally zingy) or Tia Fourte (occasionally strident).

Despite its bass emphasis and relatively milder treble, you’d think EVO was a darker-tuned IEM, but that’s not the case. It’s not bright – though some tracks lean that way when they hit the lower treble region with too much energy. For those seeking more energy up top, and like their treble to sparkle like a Christmas tree, EVO is probably not your IEM. The same goes for those who seek an abundance of lightness and air.


Technicalities

Where EVO is a shift away from the warmer, more organic-sounding Legend X tuning, the two are even further apart when it comes to technical ability. Let’s not forget that Legend X was, and is, technically very capable. It has excellent wide staging, good resolution, and commendable imaging and separation despite an overall thicker sound profile. EVO, on the other hand, is a technical upgrade in every single metric. In fact, I don’t think there’s any technical aspect of EVO’s performance that Empire Ears hasn’t managed to improve, either through fine-tuning, better drivers (Weapon IX+), a more efficient crossover network, and of course the inclusion of Weapon X.

Soundstage is the first metric that’s audibly wider with EVO. While depth and, to a lesser extent height has also been improved, the added width gives EVO a spacious, elliptical-shaped stage with many instances of out-of-head sounds appearing from virtually nowhere. Listening to the right and left channel shakers in the intro to the Eagles live performance of Hotel California captures the sense of space in the venue, combined with the layered crowd effects. Meanwhile, Yosi Horikawa’s Bubbles are generously spaced out on a wide and, on this particular track, tall stage.

With Weapon X adding reverb to certain sounds in the mix, I’m hearing more space and ‘air’ around the vocals. Normally intimate vocals, like Heidi Talbot’s in Cathedrals, shrink the stage the closer they come to the listener, but instead EVO creates a void around the vocals so they’re almost floating in space, perfectly centred, with instruments and effects moving around and beyond them. Instead of creating silos on the stage, however, EVO somehow integrates them into a cohesive soundscape.

Imaging is the most obvious beneficiary of EVO’s fleshed-out stage, with instruments, effects and vocals precisely positioned – and sometimes not where you’ve heard them positioned before. The centre image is very solid, without any diffusion or confusion about where the vocals are coming from. Better yet, on some recordings where the singer moves around the microphone, like Meiko covering Crush in David Chesky’s binaural recording of Playing Favorites, it’s easy to follow her as she takes even a few steps to the left, right or backwards. This precision certainly isn’t unique to EVO, but I’ve only heard it presented this convincingly on the very best technical IEMs like Fourte and Traillii.

Separation and layering of the different sounds and elements are the third major quiver in EVO’s technical bow. Regardless of how complex the music becomes (with a few notable exceptions), no instrument, vocal, or special effect is lost in the mix. Even subtle details can be picked out from the crowd, and backing vocals two or three rows deep are distinct in their own space.

The soft backing vocals whispering behind the lead singer in Dadawa’s Sister Drum are never impeded by the main vocals or instruments, and Luke Doucet’s vocals are clear as day even though they’re tucked right behind Melissa McClelland’s lead (and a droning bassline) in Whitehorse’s Dear Irony.


Resolution is the glue that ties these technical elements together. I don’t think EVO would be able to pull off this level of technical acuity without top-tier resolution across the board, and the jump up in resolving power from the likes of Legend X and IE 900 is significant. It’s not just the clarity that’s been added by tuning tweaks, or the space created by Weapon X, this is raw resolution.

Plug into a highly resolving source, like an R8 or Hugo2, and you’ll be rewarded with inflections of vocal chords and the wet breath of singers standing way too close to the microphone. Play back the famous ‘clocks’ intro to Pink Floyd’s Time, and every gear shift, every hand movement, is clearly audible. You’ll even hear the PA announcer directing passengers to their seats in On The run, the preceding track on Dark Side of the Moon, all the while spaceship and laser gun effects zoom past your head, left to right.

Dynamics could be a descriptor for EVO itself. It’s an incredibly dynamic IEM, with an ability to shift from the quiet, monotone build-up to Hans Zimmer’s Mountains, for example, before exploding into life in a rousing, emotional wave of sound (2:02), an experience in-ear as much as it was on screen. Angel Olsen’s Lark is a more contemporary example, with bursts of powerful vocal crescendos mixed with quiet, contemplative passages and subdued instrumentation. As is the climactic conclusion to Daft Punk’s Contact, a crazy mix of crunchy sound effects and explosions that puts you inside the doomed space capsule.



The X-factor

This is where I’d normally end the sound impressions section for most reviews, but I’d be remiss not to mention the importance of bone conduction in general and Weapon X specifically when it comes to shaping EVO’s overall tonal landscape.

The way Weapon X affects what you’re hearing really depends on the information in the track. It’s not a blanket ‘filter’ that’s going to predictably make certain changes to the sound. The effect can be subtle, and most often is, but at times is also very obvious. For me, EVO’s X-factor, excuse the pun, is in how it blurs the lines between what’s heard and felt, which adds to the realism and accuracy of certain instruments and sounds.

Take the kick drum in the intro to Big Thief’s recently released single, Changes. Most of us have heard a real kick drum before, and when pedal hits the skin, it’s much more than just a sound you’re hearing. You can feel it, from the initial punch to the hardness of the hit, to the natural decay. Many IEMs with good dynamic driverssimulate this feeling quite effectively, but EVO adds a realism I can genuinely feel from my head to my torso. Of course it’s not the same full-body feeling you’d get from a live performance or actual speakers, but it makes it much easier for your mind to take you there.

Weapon X doesn’t just add to the realism of sound, it also adds to realism of stage. This isn’t limited to the bass frequencies either, although if you’re wondering how EVO manages to keep the thunder so separate from the lightning, so to speak, it’s because Weapon X is working on the resonance and reverb and other aspects of the sound that help place it on the virtual stage.


Angel Olsen’s pristine vocals in Chance, the closing track of her brilliant LP All Mirrors, don’t just decay, there’s an added echo that helps me see the size and shape of the space she’s singing in. This is a very specific Weapon X effect that affects vocals in particular, since I haven’t heard them presented in quite the same way with other IEMs. Another Weapon X feature affects the treble frequencies, predominantly in bell and chime sounds such as those in the mediaeval instruments of Angels of Venice’s Trotto. The last time I heard this type of sound reproduction was from a full-size silk-domed tweeter.

With its new Weapon IX+ drivers and re-tuned custom balanced armatures, EVO would still have been a worthwhile, if less substantial, revision to Legend X. Adding a full range bone conduction driver in Weapon X makes EVO a new class of IEM altogether, and something that I believe we’ll be seeing much more of in the not-too-distant future.


Simply put we’ve maximized and mastered the performance of current IEM driver technologies through air conduction. From here, our only goal was to elevate the listening experience, evolving it once again to redefine what’s possible with IEMs. [For example] EVO’s ability to effortlessly compartmentalize and layer lower bass without interfering with any of the other frequencies is perhaps one of the most challenging yet remarkable things we’ve achieved to date. It really just takes what the Legend X did well to an extraordinary new level.


Select comparisons

EVO and Legend X. Seeing how I kicked off this review with a preface about Legend X, and how EVO came to be, it’s only fitting that this is the most relevant and important comparison to make. It wasn’t too long ago that Jack hinted there was not going to be a Legend X successor, and from early EVO impressions, some are saying there indeed isn’t and that EVO is something entirely new.

For me, EVO is very much a Legend X successor, at least spiritually. The mantra that ‘you can’t go past Legend X if what you want is the best and biggest bass in the business’ has now unequivocally been passed on to EVO. That EVO grabs this notion and takes it well beyond the capabilities of Legend X doesn’t mean it’s no longer comparable, but rather that, like anything audio, some may prefer Legend X’s more restrained tonality and forgiving technicalities over EVO’s extension in every metric.

Design and fit. EVO is notably larger, thicker, and heavier than Legend X, although EVO’s nozzle makes it slightly easier for me to get a good ‘shallow fit’ seal than I do with Legend X. So, while Legend X’s shells fit more easily inside my outer ear cavity, EVO’s fit fine too, even though they fill out my ears completely.

Neither IEM ‘disappears’, to put it another way, and while I’m constantly aware of both of them while listening, it’s not to the point of distraction, and some may even prefer that ear-filling feeling. Both IEMs also share the same silky-smooth finish and classy all-black design that make them, to my mind, two of the better-looking IEMs currently available – yes, even better looking than flashy abalone or Bifrost, if you ask me – though EVO’s black shell is slightly less opaque.

The supplied accessories for both IEMs are visually the same, except for EVO’s Genesis cable being far superior in every way to Legend X’s entry-level Effect Audio Ares II – a decent cable in its own right but no match for the PW Audio alternative.

Sound. Tonally, both IEMs are variations of a W-shaped tuning, though it’s easier to push Legend X closer to an L-shaped tuning, especially with its stock tips and cable. I don’t hear EVO to have less bass than Legend X, especially since it’s much easier to power EVO’s Weapon IX+ drivers than it is to get Legend’s dual Weapon IX drivers to wake up, but quantity is neither here nor there; these are both unashamedly bass boosted IEMs, and proud of it.

Where they differ more drastically is bass quality. EVO’s bass quality is a step or two up from Legend X, its upgraded woofers more resolving, more controlled, more precise, more multifaceted. EVO’s bass is also faster, effortlessly keeping pace with quickfire EDM basslines, while Legend X has a warmer, more organic quality to its bass, with slower attack and decay making it sound more romantic than natural.

EVO’s boosted (upper) midrange is another departure from Legend X’s more recessed tuning. Legend X, with its thicker lower mids and warmer upper mids is also wetter and more organic than EVO, which is clearer, more resolving, more forward, and more neutral leaning in tonality. Most people I’ve spoken to who prefer Legend X’s tuning to EVO’s cite the midrange differences as the main reason.

Both EVO and Legend X have a relaxed approach to treble, at least in comparison to their elevated bass, though EVO’s is more extended, smoother, and less peaky than Legend X’s, which can sometimes be a touch spiky, especially because it rises further up from the relatively subdued upper mids. Where Legend has a touch more sparkle, EVO has more air up top, and also sounds more natural to my ears.

Technically, as I’ve hinted earlier in the review, EVO is a step up from Legend X, literally across the board. Wider, larger soundstage, more precise imaging, better separation and layering, more resolution, and better dynamics are all checkboxes in EVO’s favour. Where Legend X has excellent technicalities for a top-tier IEM, EVO stands shoulder to shoulder with some of the best technical performers on the market.

Jack and Dean consider EVO to be the Legend X successor, and I agree. Other than a relaxed midrange tuning, which is possibly better suited to more aggressive genres, and the sentimental value of owning the original, iconic audiophile basshead IEM, I can’t see any reason to keep Legend X and EVO in the same collection when the latter performs at a consistently higher level with most types of music.


EVO and IE 900. Why would I compare a diminutive single dynamic driver IEM with one of the largest 8-driver tribrid behemoths? Probably because anyone who’s heard Sennheiser’s flagship can attest to how far it punches above its equally ‘diminutive’ pricetag, for a flagship anyway, and how bass performance is one of its standout features compared to any current IEM, regardless of price. Other than Legend X, it also happens to be the only other TOTL IEM in my current collection, so there’s that.

Design and fit. If there’s one aspect where the IE 900 has EVO beat hands-down, it’s fit. Yes I know, some have tried and failed to find a good fit with this laughably small IEM and its basic set of stock tips, but slipping on my trusty Acoustunes I was floored at how simple, seamless and comfortable it is to wear, even with a slightly deeper fit than I’m normally used to. Unlike EVO, the IE 900 literally does disappear in my ears, and after a few minutes’ use, I almost forget I’m wearing them, which adds to the spooky effect of its massive sound coming from seemingly nowhere.

The IE 900 has a fold-over shape like many on-stage monitors – even though it wasn’t designed for stage use – that slips into my ear canals with only a small faceplate on the outside to show for it. It’s made of precision CNC-polished aluminium that weighs next to nothing yet feels cool to the touch, and will likely stand up to far more punishment than EVO’s shiny resin shells ever could, not that I handle it any less carefully than I do EVO.

Sennheiser’s choice of stock cable is also controversial, with memory wire ear loops that are thicker and heavier than the shells themselves, and a tendency for microphonics when rubbed up the wrong way. That said, in my opinion, the stock cable is a better fit for the IE 900 than Genesis is for EVO, and while I do get better performance out of my custom Cardas cable, it doesn’t warrant the change as much as it does with EVO. Sennheiser also supplies three cables, each with different terminations, while EVO ships without any adapters for Genesis’ Pentaconn plug to other common formats.

Sound. Sennheiser’s flagship was a surprising revelation when I first heard it, with a natural sound that kept everything in balance, an easy-listening tonality, and bass quality unlike anything I’d heard before in an IEM. Even with Legend X in my collection, IE 900 rendered bass in such a unique way that I started giving it more ear time despite my penchant for Legend X’s low-end wiles.

EVO turns the tables with a bass presentation that goes even further. Its bass is more visceral, physical and multi-dimensional, making IE 900 sound neutral by comparison, even though they’re not too far off each other in actual elevation. EVO’s bass is also more resolving, reaching deeper into the sub-bass, although both put more focus on sub-bass with a gradual rise to a flatter midbass, my preferred bass tuning.

IE 900’s midrange is airier and more diffuse. Lower mids are fuller and more present than EVO’s, giving gravitas to thicker male vocals and instruments in that region, while upper mids sit well below EVO’s and lower, relatively, than the bass, reducing the emphasis in the presence region and placing vocals slightly farther back as a result.

EVO’s treble is more relaxed than IE 900’s, where the Sennheiser has significantly more treble energy in the lower and middle treble between 5kHz and 10kHz. That said, IE 900’s treble isn’t harsh, sibilant or bright, but can, occasionally, colour the upper midrange harmonics with some added zing, whereas zing doesn’t exist in EVO’s treble vocabulary.

Technically, while IE 900 is a strong performer, EVO is in a different class altogether. It has a wider stage, comparatively, though IE 900 matches EVO’s stage for depth and, track-depending, height. IE 900 is more coherent, but EVO is in turn multi-layered, with more precise imaging, better separation, and higher resolution across all frequencies. EVO is also more dynamic, but IE 900 is lively in its own right.

Ultimately, I find EVO and IE 900 to be more complementary than competitive. IE 900 is an easier, safer, more balanced all-day listen, with its exceptional comfort and miniature dimensions, whereas EVO is better suited to shorter, more focused listens when nothing but the very best sound quality with maximum intensity will do.


EVO and Traillii. This is the big one, isn’t it? EVO compared to the summit-fi darling, the IEM that can do no wrong. I’m being glib, of course, because I really do love Traillii, and these two IEMs couldn’t be more different if they tried. But don’t let facts get in the way of a good dust-up, and let’s see what happens when the unstoppable force that is EVO hits the immovable object that is Traillii.

The elephant in the room, as is often the case with Traillii, is the sticker price. Traillii retails for twice as much as EVO, and even though it includes a much more expensive cable, its value proposition is ultimately nowhere near as attractive as EVO’s. Traillii also appeals to a very different audience, one less enthused by bombastic sound and favours a safer, more relaxed, and arguably more versatile tuning. Ultimately these two IEMs make better bedfellows than they do competitors, and if money is no object, make an almost ideal complementary pair for truly summit-fi sound.

Design and fit. Traillii and EVO are not entirely dissimilar in their build. Traillii’s clear, medical-grade resin shells and painted top plate are similar in feel to EVO’s, though I’m unsure if Traillii shares EVO’s protective lacquer coating. Size-wise Traillii is a fair bit smaller than EVO and about the same size as Legend X, with a shorter, thicker nozzle. Traillii’s nozzle notch makes it easier to keep silicone tips secure than EVO’s smooth, notch-less nozzle, but also harder to get many tips on in the first place. The thicker nozzle also limits the type of tip that fits.

In the ear, Traillii is the easier wear, and those with larger ears may need larger tips to fit them securely. And, as mentioned earlier, Traillii’s PW Audio-made cable is a more expensive variant of the company’s 4-wire ‘The 1960s’, a $2,000 cable that’s better performing but less ergonomic than Genesis.

Sound. While Traillii and EVO share a W-shaped tonality in theory, Traillii is more balanced and closer to neutral, while EVO is bolder, especially in the bass and upper midrange, with a more relaxed, tapered treble.

It’s difficult to compare the apples and oranges that are EVO’s and Traillii’s bass, the former powered by twin 9mm dynamic subwoofers and a 10mm bone conduction driver, the latter by two miniature BA drivers. Traillii’s bass makes a good case for the most realistic, and I daresay dynamic driver-like bass, in a BA-bass IEM, at least of the ones I’ve heard, but it doesn’t really challenge EVO’s powerful, deep-reaching, visceral bass in terms of quantity or, in my opinion, quality. That’s more preference than fact, and I know many people who actively seek out less bass than what EVO has on offer, for that very reason.

Midrange is a wash between the two, Traillii being fuller in the lower mids compared to EVO, and not quite as forward in the upper mids, giving it a lighter touch with female vocals. Traillii’s lower treble dip makes it sibilance-proof, much like EVO, and further up, its quad e-stat drivers deliver more sparkle and air compared to EVO’s neutral-leaning treble.

Technically, both Traillii and EVO are tour de force IEMs. Traillii’s stage is wider, deeper and taller, but only fractionally. Imaging on both is top-notch, with Traillii putting more air between instruments and revealing more layers in the music. Resolving power is on par, with EVO improving on Traillii’s bass and midrange detail and clarity and Traillii countering with more detailed treble.

Where EVO puts you on stage with the band, up close to the singer and right next to the drums and horns, Traillii seats you in the fifth row, close enough to enjoy every nuance and detail of the performance, yet far enough that nothing jumps out at you unexpectedly. As mentioned above, these two IEMs deserve a place alongside each other in any high-end collection, and work better together than apart to cover almost every genre, presentation and mood imaginable.


Final analysis and closing thoughts

Where does one begin summarising the strengths of an IEM that’s so different to anything that’s come before? Before I give you my verdict, here’s Jack’s take:


With a legacy born of Empire Ear’s class-defining icon that is Legend X, Legend EVO is the new dawn, giving us the first tangible glimpse of what the future holds for the brand and the sound. Bass is again the foundation, but it defines EVO far less than it did its predecessor, with a tonality that seeks balance over brawn, and technicalities that elevate it to the top tier of contemporary high-end monitors.

Emotionally and physically, EVO puts me in the front row at a live performance, sometimes even closer – on stage with the band. It’s a powerful, energetic sound that is more immediate than holographic but still has a unique 3D presentation that I haven’t heard with other IEMs. At the same time, its timbral accuracy is astonishing, rendering instruments and vocals so realistically I can almost touch them.

Key to EVO’s sound is a wholly-reimagined approach to presenting music, using specialised bone conduction technology in a new and unique way that goes beyond what was previously possible with traditional multi-driver air conduction techniques. Weapon X might be the first driver of its kind in an IEM, but it won’t be the last, and I expect the technology will filter down to the mainstream before long.

For now, EVO is a compelling prospect for any audio enthusiast for whom powerful, energised, dynamic, and emotionally engaging sound is a priority. It shirks safe for stupendous and does things with familiar music that sometimes takes several listens to appreciate and embrace. For me, it’s an easy recommendation, epitomising the state of the art and ticking almost every checkbox I have for a high-end musical monitor.

Full disclosure: Dekoni sent me the complete set of Elite HD800 pads to test and review on my own system with my own pair of HD800 headphones, without fear, favour or any expectation for preferential treatment or specific outcomes. The views and notes below are my own, and entirely reflect my own hearing, taste in music and sonic preferences in sharing them here.

It took me many years to warm up to the genius that is the Sennheiser HD800. Coming from unashamedly ‘basshead’ roots, the HD800 always seemed to me to be an over-hyped, overpriced headphone that appealed to audiophile ‘snobs’, with their hoity-toity classical and jazz-inspired playlists.

And yet with the years the HD800 just seemed to hold its own as a headphone that many aspired to emulate but only ended up poorly imitating. Even Sennheiser’s own HD800S, supposedly designed to address the few shortcomings of the original – namely a ‘nasty’ 6kHz spike and strident treble – split enthusiasts down the middle, with the likes of Innerfidelity’s Tyll Herstens boldly declaring the HD800S failed to measure up to its older brother in some key areas (bass distortion and muddled mids, for instance).

For everything the HD800 (and HD800S) had going for it, it somehow also spawned a sub-industry of modifications for beginners and enthusiasts alike (one of which, the SuperDupont Resonator or SDR mod, I wholeheartedly recommend as an essential upgrade). But, until recently, there was nothing that suggested the very interface between the HD800 and your head – the pads – needed tweaking.

Considering how ‘pad rolling’ is part and parcel of modern-day head-fi, you’d think this a little strange, until you realise that the HD800 is so sophisticated in its simplicity that even the smallest change can make a massive difference to how it sounds, and that most changes take the sound too far away from the HD800 ‘sweet spot’, the very sound that makes it so special and so preferable to so many.

Dekoni Elite – a pad rolling panacea

Dekoni Audio has built a well-deserved reputation for making high-quality replacement pads for some of the world’s most popular headphones. I reviewed their pads for Focal’s Elear here, and found them to markedly improve on both the sound quality and build quality of the original pads. That said, the Elear absolutely needs a pad change to sound its best; the HD800, as I’ve grown to appreciate, does not.

Not only is the HD800 one of the most ergonomically comfortable headphones I’ve ever worn, the pads strike an almost ideal balance between comfort and sound quality. The HD800 does what it does not only because of its massive dynamic drivers, expertly engineered cups, and optimised mix of materials, it’s about the sum of its parts. Change one, and the risk is you change everything else.

That goes for the pads too. There’s a reason Alex Grell chose the size, shape, thickness and materials for his pads. And yet in designing their range of Elite pads for the HD800, Dekoni unapologetically broke all the rules by changing not only the material but also the shape, thickness and construction of the original pads. Would it be one change too many, or have they somehow found a solution where no-one else had previously thought of looking?


Dekoni’s Elite series of pads almost always includes four different versions, and the HD800 family is no different. I received one each of their Elite Sheepskin, Elite Fenestrated Sheepskin, Elite Velour and Elite Hybrid pads in sturdy, well-constructed boxes. Each pad type is identical bar the construction materials, which, like all other previous Dekoni pads, are made from high-quality heat activated memory foam inners and real leather or plush velour outers. Along with the pads, Dekoni supplies a small plastic tool for removing the original pads, and a printed set of instructions showing how to mount (and unmount) the Dekoni pads onto the headphones.

Removing the original (OEM) pads is simple, made even simpler with the Dekoni tool. A few careful plucks, and the pads pop off from the cups with ease, exposing the original perforated Sennheiser dust covers in each cup. At this point I advise you remove the original dust covers, because the Dekoni pads have their own built-in, non-detachable covers, and in my listening, I found that two layers of dust covers were not only overkill but also added a thin and unwanted veil to some of the music.

Some have suggested the Sennheiser dust covers are integral to the HD800’s sound signature, and cut away the Dekoni covers instead. Not wanting to mutilate perfectly good pads, I decided to take the easier option, but the brave among you may want to experiment differently.

Installing the Dekoni pads is equally simple; line up the tabs on the back of the Dekoni pads with the indents in the HD800 cups, and carefully work your way around each pad, pushing in along the edge until it ‘clicks’ into place. In less than a minute the changeover was complete and listening could begin.


Before we get into comfort and sound impressions, a quick note on removing the Dekoni pads, because as easy it is to install them, removing them is anything but. If you’re like me and baby your HD800 more than you baby your babies (and for good reason, babies don’t come with paint that chips just by looking at it), then you’ll want to be extra super cautious when removing the Dekoni pads from your babies.

Inserting the tool and getting the first ‘pop’ is easy enough, but unlike the original pads that seem to pop off in one smooth motion, the Dekoni pads pop and then hold fast at every adjacent clamp point. According to the instructions, the trick is to grip the pads after the initial pop and then gently (and by that they mean firmly) twist the pads around and away from the cups without breaking anything in the process.

I believe bomb disposal experts have had less nerve-wracking experiences with far more dangerous equipment, but after some profuse sweating and less-than-profound language, I seem to have perfected the art of Dekoni HD800 pad removal. Still, I only attempted it four times – as many times as I needed to install and listen to each of the different pads for the purpose of this review – and I’m glad to say my beloved HD800 still looks good as new.

Look, feel and touch

The first thing you’ll notice about the fit of all four Dekoni Elite pads is how much thicker they are compared to the original pads. The face of each pad is fat and flat, unlike the round and shallow profile of the originals. Also, unlike the original pads that are filled with a squishy, semi-firm foam, the Dekoni pads are filled with a heat-activated memory foam that’s initially quite stiff and cold to the touch but quickly softens as it’s warmed up and ‘moulds’ to the contours of your face.

The extra size takes a bit of getting used to, both visually and physically. In my case I needed two or three further clicks on the headband to get the pads to sit flush with my ears on my very average-sized head, and while I love the look of the pads, they do make the HD800 seem a little less refined and more aggressive in appearance. Size-wise, take note, because if your head is larger than average and your HD800 headband is already maxed out, then you might find the Dekoni pads are just too tight for comfort. Conversely, if the HD800 has worn too loose on your head until now, the Dekoni pads will grip you like Goodyear tyres on a freshly tarred road.

Speaking of grip, one of the advantages of the HD800, for me, is its relative lack of clamp with the original pads. Due to the thickness and resulting slight change of angle of the cups on my face, the HD800 with Dekoni pads is both tighter and grippier. It’s not uncomfortable, it’s differently comfortable. The Elite Velour and Elite Hybrid pads are the most comfortable of the set, like two warm cushions on the skin, and while the leather pads are supple and smooth to the touch – and the leather is good quality real leather rather than the cheap pleather used on so many other aftermarket pads – they’re slightly harder and cooler, at least initially.


Sound impressions

All the comfort in the world doesn’t make a difference if the sound isn’t up to par, and on the whole, the sound quality of the HD800 with all four Dekoni Elite pads is excellent. It’s also different to stock, no matter what it says on the tin, so how much you love the ‘original’ sound (or in my case the HD800 SDR sound), and how far you’re willing to go for better fit or comfort (if indeed the Dekonis are more comfortable to you), will determine how much more (or less) you like them over the stock pads.

In designing the HD800, Dekoni founder and owner Tal Kocen said the one thing he tried to do was to smooth out the 5kHz (although most measure it as 6kHz) peak and by testing with different baffling materials. He also suggests the ‘openness’ of the HD800 design means that sound changes are far more subtle with a pad swap compared to pad rolling a closed headphone, and that “the biggest difference is that while they don’t necessarily change the frequency response much, they move the drivers away from the ear and create more space within the headphone.”

I took time to listen to each set of pads, taking notes using my tried-and-tested playlist to listen for particular nuances in the sound. Most of the pads were tested using most of the playlist, which includes (but isn’t limited to):

Amber Rubarth– Hold On (from Sessions From the 17thWard)

Heidi Talbot– If You Stay (from Love & Light)

Lana Del Rey– Video Games (from Born To Die)

Norah Jones– Come Away With Me (from Come Away With Me)

Thomas Bergersen– Gift of Life (from Illusions)

Def Leppard– Love Bites (from Hysteria)

Angels of Venice– Trotto (from Angels of Venice)

Jethro Tull– The Waking Edge (from Crest of a Knave)

Lorde– Royals (from Pure Heroine)

Max Richter– Winter 1 (from Recomposed by Max Richter – Vivaldi: The Four Seasons)

My HD800 listening aligns fairly closely with my preferred musical styles, those being acoustic female vocals, female-driven pop, light classical, cinematic scores, female vocal jazz, and soft rock. I listen to other genres as well, but in most cases anything that needs a heavier hand with bass or warmer, more intimate vocals is deferred to my second love, the ZMF Auteur.

It’s safe to say that if your listening tastes closely align with mine, you’ll find a lot to like, and much to love, with the Dekoni Elite pads. To keep it simple, I’ll cover how Dekoni measure and describe their own pads, and then compare what I heard with each of the pads on my own system.

Elite Velour

Dekoni: The biggest difference here is the Elite Velour pad will absorb a little more of the high frequency material and so you see a ~3dB dip between 10kHz and about 14kHz. It seems to take away some of the sparkle but causes the overall warmth to get accentuated a bit. Again, though, we see that 5kHz peak diminished and the high frequency material smoothed out.

My impressions: Easily the warmest of the pads, both in comfort and in sound. The opening sequence of guitar plucks on Heidi Talbot’s ‘If You Stay’ are as crisp and bassy as ever, but also a touch more resonant, with a slightly longer decay. That’s very possibly a factor of the added volume between ear and driver – something which also results in a marked decrease in volume over the stock pads. This applies to all the pads, not just Velour, so be mindful when making your own comparisons.

On that note, all the Dekoni pads will make your HD800 sound softer at the same volume setting, which could trick you into hearing differences in the sound profile that are only there because of the lower volume. Turn the dial up a bit to hear what the pads are really doing to the sound. I didn’t expect the volume drop to be as steep as it was, and to be honest is the change I liked least.

All that said, the change from stock sound, once volume matched, is subtle. With the SDR mod and mild EQ (I use SonarWorks religiously with my HD800 and don’t make any excuses for it), I never have an issue with treble spikes or glare, but the Dekoni Velour pads did take a hint of air away from the upper registers, and expanded the stage ever so slightly. Bass and mids, from what I could tell, were mostly unchanged.


Elite Sheepskin

Dekoni: This one makes the most sonic difference as the Sheepskin material by nature is thicker and less porous than the others. What this means is that the sheepskin does not absorb much of the material that hits it, it just keeps the material moving on through to your ear. The high frequencies don’t get absorbed at all and you maintain more material and ‘air’ to what you’re listening to. This pad is great for a little extra lift in the top end.

My impressions: oddly I found the Elite Sheepskin pads to have the least audible change from the original pads, probably because of all the pads they also had the least pronounced volume drop. It’s also possible that the music I listen to is generally well recorded with few glaring peaks, and I don’t have an extensive classical playlist, so perhaps the ‘strengths’ of this pad were lost on me.

Def Leppard’s cymbal splashes at around the 1:20 mark of ‘Love Bites’ can make or break a headphone for me, and if the extra ‘lift’ of the Sheepskin pads supposedly made this part any more strident, I didn’t hear it. Then again, I do have a particularly odd manifestation of hearing loss (called Cookie Bite, Google it), so it’s possible that the extra bite of the pads was cancelled out by the bite in my hearing, and the pads fit my hearing like a proverbial glove. Also I have a thing for leather pads, so of all the Dekonis, these were easily my favourite.


Elite Fenestrated Sheepskin

Dekoni: The frequency response on this one is almost identical to the Hybrid Pad, that is to say very little difference in the sound signature all the up to about 2kHz. The main difference between the two is comfort, depending on whether you prefer the feel of leather or velour on your skin.

My impressions: the biggest change for me with the Elite Fenestrated Sheepskin pads – which prior to receiving them I thought would be my favourite, given my penchant for the ‘fenestrated leather’ look – was the added airiness in the sound. Dekoni’s Fenestrated pads for the Focal Elear were easily my preferred choice for that headphone, and in hindsight that could be because of how well they balanced the Elear’s heavy-handed bass attack with the other frequencies. In the case of the HD800, I’m not sure the trick works as well, if only because the HD800 is not the world’s most bass-endowed headphone to begin with (which is also why my SonarWorks profile raises the bass level a few notches above neutral).

The heft of the mediaeval drums in Angel of Venice’s ‘Trotto’ was nowhere near as pronounced with these pads as it is with the stock pads, Sheepskin or Velour. Lorde’s ‘Royals’ also didn’t have the same aggressive thump that makes this track my litmus test for bass response. That said, if you prefer your bass leaner and more refined, the sound profile of the Fenestrated pads may be just the ticket. Strange as it seems I’ve heard the HD800 described by some as ‘warm’, especially with the SDR mod, and if you don’t like your sound too steamy, the combination of a bigger stage – even bigger than the stock HD800’s industry standard – and leaner bass will make for an appealing sonic cocktail.

Looks-wise I thought these pads would also be the most impressive, but unlike the Elear equivalent, the holes of the HD800 pads are larger, showing more of the yellow memory foam beneath, and giving the pads a less even appearance than I would have liked.


Elite Hybrid

Dekoni: Much like the Fenestrated Sheep, the Elite Hybrid does little to change the sound profile of the HD800 up to 2kHz. You will also notice a smoother transition out of the ‘conchal bowl’ and a nice arch over the peak while maintaining a little more of the higher 10kHz+ material which adds some air and a hint of sparkle to the sound.

My impressions: The Hybrids, like the Velours, were the most comfortable of the lot, but I have to say I find the combination of materials rather odd looking. This isn’t limited to the HD800 pads – I also found the Focal Hybrids rather odd. They have a ‘stitched together’ look that’s somewhat out of character with the pristinely precise construction of the HD800, but I guess the contrast could also make them oddly appealing to some.

In any case, the sound of the Hybrids tallies closely with Dekoni’s findings, although I did find them reducing the bass more than I’d typically want them to given the low base the HD800 starts you off with. If you do EQ your sound you may want to up the bass a touch along with the volume. The instrumental intro sequence to Jethro Tull’s ‘The Waking Edge’ covers almost the entire frequency spectrum, with some potentially piercing pings and razor-sharp guitar strings, and not once did I wince with the Hybrids on my ears. That a good thing for both my ears and the pads, and if you like the look, want the velour comfort and are happy to live with a slightly less hefty sound, these could be the pads for you.


Closing thoughts

You have to hand it to Dekoni: taking on an absolute classic headphone and tinkering with what many consider to be as close to perfection as you’ll get from a headphone is brave at best, reckless at worst. Fail and not only do you lose a sizeable investment in expensive materials, but your reputation among the Elite – excuse the pun – takes a solid hit.

On the whole, I think Dekoni have pulled it off very smartly indeed. They didn’t pretend to make a ‘better original’, rather going the route of ‘different original’. They put their cards on the table, clearly identifying the issues they wanted their pads to solve, and backing themselves with measurements that show where the differences – beneficial or otherwise – sit on the charts.

For someone like myself, who took a long time to fall in love with the HD800 but when I finally did, fell in love with it wholeheartedly, changing anything about this headphone was never going to be something I did without much trepidation. It took weeks of reading and convincing myself that a ‘serious’ mod like SDR was even fathomable (it turned out to be so easy and also so easily reversible as to seem rather insignificant after the fact), that a pad change was an order of magnitude more intrusive.

But Dekoni clearly did their homework with this set of pads. Even though removing the pads can induce a sudden bout of nausea, once you’ve done it successfully – by actually trusting the instructions – it’s all smooth sailing. Installation wobbles aside, the fact that Dekoni has created a set of pads that are not only better made than the originals but also use more expensive materials without actually being more expensive (not much anyway, and much cheaper if you’ve opted for Velour), makes them outstanding value and well worth a try even if, like me, you’re married to the original look and feel of the HD800.

Do I recommend them? Absolutely. There should be at least one of the set that most people will either find more comfortable, better looking or better sounding than the original pads. Whether or not I go back to using a pair of Dekoni Elite pads with my own HD800 remains to be seen. SDR aside, for now there’s just something about this headphone I never, ever want to change, and probably never will.

Once in a while, I come across a product in this hobby that doesn’t quite fit into the normal boxes. iFi’s xDSD Gryphon (or just Gryphon if you’ll allow me) is a good example.

Combining elements from two previous products – xCan and xDSD – and adding some interesting new tech of its own, Gryphon is a new portable DAC and headphone amp platform that combines many different technologies introduced and perfected in other iFi products into a compact, advanced, and very accomplished performer.

In doing so, it ambitiously aims to cover multiple bases for multiple use cases. Whether you want hi-res Bluetooth input (including LDAC support), hardware MQA decoding, a proven multibit DAC with native DSD and DXD support, a fully-balanced amp architecture with 4.4mm inputs and outputs, Gryphon does it all, and much more.

In fact, it tries to do so much that it risks becoming a jack-of-all-trades, but as I discovered in the past few weeks, it pulls it off the juggling act remarkably well, making it far more than the sum of its many parts.


Spec sheet

Before we dive into the review proper, let’s take a bird’s eye view of everything Gryphon:

• DAC: Hybrid multibit Burr Brown
• Formats: PCM 768/DXD/DSD 512/MQA Studio Master
• Outputs (headphone): 4.4mm balanced / 3.5mm single-ended + S-Balanced (3.5mm balanced)
• Outputs (line): 4.4mm balanced / 3.5mm single-ended
• Inputs (analogue): 4.4mm balanced / 3.5 single-ended
• Inputs (digital): USB-C (up to 768kHz), SP/DIF (up to 192kHz), Hi-Res Bluetooth (up to 96kHz)
• Bluetooth (input only): v5.1 support (SBC, AAC, AptX Adaptive, LDAC, HWC)
• Battery: Up to 8 hours, separate USB-C charging port and dual digital input/charging port
• Power output (single-ended): >320mW @32 Ω (headphone); 3.5V variable (line out)
• Power output (balanced): >1W @32Ω (headphone); 6.7V variable (line out)
• Output impedance (headphone): <1 Ω
• THD: <0.005% (1V @ 16Ω)

A boxful of tricks

The unboxing experience is much the same as that of other recent and past iFi products, which is to say very high quality. Gryphon ships in a lidded box, complete with a colorful cardboard sleeve full of specs, features, and lots of pretty pictures. Inside, you’ll find Gryphon covered in a soft wrapper, along with a warranty card, fold-out user guide, a velvet-lined carry pouch, and three cables: two short USB-C to C and USB-C to Lightning cables for connecting to smartphones and tablets, and a longer USB-C to A cable for hooking Gryphon up to laptops and desktops.

I would have preferred a harder protective case (I have one on the way from my go-to case maker, Miter), which would have been a welcome addition for someone like me who babies gear against all manner of domestic household dangers. Also, since Gryphon is small enough to be used in a stack with a phone or DAP, I’m surprised iFi didn’t include any elastic rings to keep the stack together. Quibbles aside, the accessory list is more than sufficient, and any of the add-ons I mentioned should soon be available to buy separately anyway.


Build and design

On seeing Gryphon for the first time, I had two reactions: it really does look just as good in person as it does in the marketing material, and it also looks and feels substantially smaller than I expected it to be for such a full-featured device.

The last iFi DAC/amp I owned was the original Micro iDSD, and that was big, bulky, and rather ugly by comparison. Gone are the industrial lines of the iDSD, replaced by a flask-like two-tone shell with a premium-feeling (and importantly, fingerprint-resistant) space grey matte finish. The case itself is about the same size and thickness as a pack of playing cards, which is to say shorter than a modern oversized smartphone but more than twice as thick. It’s also fairly stocky at 215g, which is understandable given all the tech and components it crams inside the metal shell.

Inspecting the buttons, dials and knobs reveals high-quality, precision mechanical finishes with just enough tactile give for fluid movement and haptic feedback, but without feeling too loose or wobbly (I’m aware of some reports of rattling volume dials, but my unit has no such issues). Four slim rubber feet adorn the base, cleverly keeping it stable on a tabletop and safely raised off your smartphone or DAP when using them as a source.

For all the possible permutations, not a single space, button or knob is superfluous. Make no mistake, Gryphon is a brilliant piece of industrial design, and one that can serve as a blueprint for even more potential functionality in future iterations (more on that later).


Features and functions

It’s worth covering all the buttons and their associated features together, because of how interconnected they all are to each other.

Starting with the most visible of these, the volume dial, not so much a dial as a multi-function knob, acts as an on/off power switch, menu selector (when inside the settings menu), and most importantly as an analogue volume control. Did I mention it can also be used to mute the volume (single press) and, with the latest firmware, gives you full pause/forward/reverse track control when connected with Bluetooth?

The fit and finish of the dial is top-drawer. Turning the dial feels very satisfying and solid with perceptible click-click-click feedback in small intervals for fine (1dB) adjustments, but without ever feeling like it’s going to slip or skip multiple volume steps (unless you turn it faster). The way it’s been positioned slightly forward means you can set Gryphon flat on a desk or hold it in one hand and still turn the dial with a gentle one-finger push or pull, which is very well thought through.

While Gryphon features a variable brightness OLED screen, you can also eyeball the volume level by the colour of the LED ring around the volume dial and the LED light on the dial itself. There are six possible ranges, from mute (no light) through to -2db to +6dB (red). Visually setting the dial to magenta (-56 to -39dB) or green (-38dB to -21dB) is an easy and safe way to know you’re not going to blow your ears off when you hit play with sensitive IEMs or headphones plugged in.



There are two more mechanical push buttons on the front face – a smaller selector button (furthest right) that switches between input types (more on these later), and a slightly larger button that toggles between the built-in XBass II and XSpace functions (again, more on these later), and also activates the settings menu with a longer press. Opposite the buttons, on the left-hand side of the face, are the two headphone output ports, 3.5mm S-Balanced and 4.4mm fully balanced, sized the same as the adjoining buttons to create a neatly symmetrical layout on the fascia.


There are also two other levers on Gryphon: one on the base that lets you activate two different levels of iFi’s IEMatch technology for sensitive IEMs, and one at the back, which toggles between three different options for the XBass II feature.

Starting with IEMatch, the options are labeled 3.5mm, 4.4mm, and OFF (default), supposedly because the more powerful 4.4mm output requires higher output attenuation than the ‘weaker’ 3.5mm output, although both settings work with both outputs. Since I don’t use IEMatch I didn’t spend much time testing for quality differences between the two, but iFi have since confirmed this is the same IEMatch technology used on its standalone and well-received balanced IEMatch accessory, which makes it a great value-add for sensitive IEM users (notably any IEM from Campfire Audio).


The additional XBass II functionality is quite different, and as far as I know, unique to Gryphon. According to iFi, with XBass II ‘you can select ‘Bass’ and/or ‘Presence’ so that the upper midrange frequencies are correctly added back into your favourite recording’. This is something I would have missed entirely had I not checked what the back toggle was all about. It also means that XBass II is more than just about bass, because it can boost upper midrange independently of bass, a potentially useful feature for IEMs or headphones that dip the presence region but don’t need any bass correction.

Combined with XSpace, which mainly affects the treble frequencies to add more air into recordings, Gryphon now has limited but effective analogue-based EQ toggles for bass, upper-midrange and treble, either independently or together in different combinations. I can personally attest to using all three settings to add flavour to some recordings, and in different ways depending on the IEM or headphone I’m using. The fact that it’s so easy to do, and that the effects are never overdone, makes this a very powerful addition to Gryphon’s feature set.


Even more features

Given the smorgasbord of genuinely useful features packed into Gryphon, perhaps the best feature of all is the DAC itself. When I reviewed iFi’s other new portable Bluetooth DAC/amp, GO blu, I noted the ‘missing’ hybrid multibit Burr Brown DAC that iFi uses for almost all of its products. Thankfully, the BB DAC is back with Gryphon, and with it, the very respectable hi-res decoding numbers and formats I felt were lacking on the smaller dongle, including full PCM 768, DXD 768, and native DSD 512 support.

Admittedly these ultra-hi-res formats are only available with direct USB input, but the fact that they’re available at all is the point here.

The DAC is ably supported by a plethora of hardware and software features, including a customised negative feedback amplification design that iFi calls OptimaLoop, which apparently uses different types of negative feedback circuits for optimal performance. Another amplification tech iFi calls PureWave is meant to be a type of optimised dual-mono balanced topology (previously only found in iFi’s higher-end NEO and Diablo amps) for Gryphon’s balanced inputs and outputs, which in theory reduces distortion and improves linearity.

Switching to software features, Gryphon offers a choice of three DSP ‘filters’ (in fact two filters and one unfiltered bit-perfect mode), selectable via the settings menu from the OLED screen. STD is a moderate digital filter with zero pre-ringing and modest post-ringing properties, while GTO (Gibbs Transient Optimised) is a proprietary iFi digital filter that upsamples all content to 384kHz/352kHz depending on the clock source, with only moderate pre- and post-ringing, which, from what I understand, combines the advantages of oversampled delta-sigma processing without the associated ringing artefacts.


Whether or not you think these filters add anything useful is again entirely up to you to decide, but I have to admit hearing some added clarity and dynamics in the sound with GTO enabled, without the presentation becoming too digital.

Speaking of the OLED screen, this is yet another major feature that’s entirely new with Gryphon, and to my mind changes it from a dumb terminal-like DAC/amp (i.e., every other iFi portable product) to something entirely different, and better. Not only does the screen look really cool, it’s also dimmable, can be switched off, and offers a second, very visible and very easy way to check which settings, volume levels, Bluetooth codecs, and inputs and outputs are active at any one time.

The screen also makes it easy to visually make fine volume changes, and is a good way to double-check you’re not about to blow your eardrums with a CyberSync malfunction. iFi has also gone as far as using special low-power circuits for the screen that supposedly don’t add any interference (noise) to the sound. They’ve even given it a name, SilentLine, if you can believe that.

But aside from being a marketer’s dream device for cool-sounding feature names, Gryphon is undeniably packed full of genuine audio-optimised hardware parts from the likes of Alps, Kemet, MuRata, Panasonic, TDK and Diodes, and I believe the quality of parts reflects in the quality of sound.


Ins and outs

Okay, this is the last stop before we get to the good stuff about sound, but to me, the star of the Gryphon show is quite simply its versatility. By that I mean all the different ways it gives you to get your music in from different devices, and the simple yet powerful ways it lets you push it out again with exceptional quality.

Starting with inputs, Gryphon supports an almost full range of digital and analogue inputs, especially for a battery-powered portable device. These include 3.5mm single-ended and 4.4mm balanced analogue inputs, S/PDIF optical and USB digital inputs, and the piece de resistance as far as I’m concerned, hi-res Bluetooth digital input. There’s even a separate USB-C input port for charging the battery independently, letting you charge up while connected to any other input (though you have the option of charging while connected to the USB-C digital input as well).

For playback, Gryphon features four types of outputs: dedicated 3.5mm (single-ended or iFi’s 3-pole 3.5mm S-Balanced) and 4.4mm fully-balanced headphone outputs, and dedicated 3.5mm and 4.4mm line-outs. To save space, Gryphon’s analogue inputs cleverly double as line-outs, switching function automatically whenever you’re using a digital input (like Bluetooth or USB) at the same time.

Since most of the above is self-explanatory, I want to rather spend some time focusing on what I consider Gryphon’s biggest advantage over other similarly-priced (and even higher-priced) portable DAC/amps: Hi-Res Bluetooth. While Bluetooth input is nothing new, the level at which iFi has implemented and refined its Hi-Res Bluetooth input technology sets it apart from any other Bluetooth-equipped device I’ve heard to date. If GO blu surprised me with the quality of its Bluetooth sound – which was only marginally inferior to its wired input – Gryphon pushes Bluetooth quality even closer.

In fact, the difference in sound quality between Gryphon’s LDAC and USB inputs is so small, for anything but the most focused listening sessions, I don’t even bother to wire it up.


There is a small sting in this tail, however. I found a bug – not in Gryphon, but rather in some source devices, like the LG V60 smartphone and a few other smartphone models – that prioritise the AptX Adaptive codec over LDAC, and therefore won’t allow Gryphon to switch into LDAC mode. While this is a very niche bug that affects a very small number of devices, the solution is seemingly a simple one – allow users to manually enable/disable the various Bluetooth codecs in Gryphon’s settings menu. By disabling AptX Adaptive in Gryphon, the buggy sources will see it as an LDAC device.

Sadly, this is not possible, yet, but I’m reliably told that the feature request has been escalated, and hope to see it made available soon. It’ll certainly return Gryphon to optimal functionality for my use case.

There’s also one more feature I’d like to see added, either to the current Gryphon – if it’s at all possible – or to a future version: Bluetooth transmission. While it might seem counterintuitive to pack Gryphon full of dedicated, high-quality audio components designed specifically for analogue output – only to bypass all of them by switching to Bluetooth – there’s a case to be made for turning Gryphon into the ultimate audio interface with this one, simple tweak. Just a thought, iFi; you can thank me later.

Sound impressions


I mainly tested Gryphon using a pair of Sennheiser IE 900 IEMs, but I’ve also made notes on how it sounds with other IEMs and headphones, including Sony’s IER-Z1R IEM and MDR-Z1R headphone. Digital sources included HiBy’s RS6 DAP, LG V60 Thinq smartphone and MacBook Pro. I used a variety of test tracks that I’m very familiar with, including (but not limited to):

• Lana Del Rey – Dark But Just A Game
• BEYRIES – Alone
• Brandi Carlile – The Story
• Eagles – Hotel California (Live)
• Agnes Obel – The Curse
• Bjork – Hunter
• Daft Punk – Contact
• James Gillespie – What You Do
• Jillette Johnson – Bunny
• Jethro Tull – The Waking Edge
• Angels of Venice – Trotto

Tonality

I hear Gryphon to have a fairly neutral and linear tonality, with slight warmth in the lower registers, but overall a clean, balanced, and generally transparent presentation. It follows a similar tuning philosophy to GO blu, which again seems to be a departure of sorts from the company’s more pervasively warmer house sound that it still uses in the Micro iDSD series.

This is not neutral in the sense that it’s reference or worse, lifeless, but rather strikes a very healthy balance between overt cleanliness and musicality. It’s not overly analytical, though it won’t do much to change the analytical nature of IEMs that lean that way unless you make use of its sound-shaping features. Instead, I find it delivers quite a rich palette for IEMs and headphones to work with, excellent timbre throughout, and just the right amount of emphasis without oversaturating the sound.

It doesn’t make sense to break down the bass, midrange and treble response other than to say there’s no obvious boost or dip in any of these frequencies, other than a slight emphasis on note solidity and speed down low, and some added air up top. Whether or not that’s a good thing for you depends on what you’re looking for from a source, and what you’re pairing with it. Personally, I prefer linear and transparent sources that support rather than those which affect specific frequencies and run too warm or too cool.

In saying that, with XBass II (and its midrange-shaping capabilities) and XSpace, Gryphon can indeed ‘correct’ the shortcomings or enhance the qualities of IEMs or headphones that need some tweaking. More importantly, it does this in hardware, not software, so there’s no quality hit to the audio chain.

I found XBass II’s bass impact is more prominent than GO blu’s, but can be tempered down using the Bass + Presence setting. The Presence-only setting is also useful for restoring upper midrange bite to IEMs like IE 900, in cases where its dip in this region is too deep for your liking.

XSpace is less a treble bump and more a subtle spatialisation effect, still affecting mainly the treble region but less obviously so than GO blu. If you’re using IEMs or headphones with limited stage width, depth or height, it’ll give you some much-needed breathing room, but I mostly left it off since stage size is never an issue with my gear.


Technicalities

The key to Gryphon’s technical performance is its ultra-low distortion and noise floor, allowing the technical performance of the IEMs and headphones I used to shine through. I don’t perceive any drop in detail or resolution, and if anything, resolution is slightly improved over the R2R-based HiBy RS6 (I’m splitting hairs here, but the RS6 does cost almost three times as much as Gryphon).

Essentially, you’re not making many – if any – technical compromises to resolution, imaging, dynamics or layering and separation when switching from a higher-end source to Gryphon. Some may perceive a slight drop in stage width compared to higher-power desktop amps, but this really depends on what you’re driving, and how well your IEMs/headphones scale with more power. In every torture-test I put Gryphon through, such as the collision sequence in Daft Punk’s brilliantly atmospheric ‘Contact’, it didn’t skip a beat, keeping the different elements separate but cohesive, and keeping a tight grip on the drivers, be they 7mm in IE 900 or 70mm in MDR-Z1R.

There are caveats to this otherwise sterling scorecard, of course. You will hear a slight drop in technical performance when switching to Bluetooth input, especially when using lower-bitrate codecs like AAC or (shock-horror) SBC. Even with LDAC, with its support for almost 1Mbit of bandwidth, the soundscape will flatten, and the fringes of vocal and instrument transients may not be rendered quite as crisply as they would with a bit-perfect wired connection.

Gryphon is also, ultimately, a highly portable, hand-held source, and as such it won’t give you the same headroom as even a basic AC-powered desktop stack. But again, unless you’re driving large planars or similarly insensitive headphones, you probably won’t notice the difference, especially with easily-driven IEMs.

Even if performance is not 1:1 on par with similarly-priced desktop gear, the convenience and freedom of being untethered from a desk (or phone) outweighs any performance issues. Moreover, Gryphon is less affected by cable power noise issues that can be problematic on desktop sources, and sometimes cost more than the sources themselves to mitigate, so you may in fact find its performance exceeds your desktop gear in some aspects.


Select pairings and comparisons

Gryphon is one of three recent releases in iFi’s portable product portfolio, along with GO blu and hip-dac 2. hip-dac lacks GO blu’s Bluetooth input functionality, but compensates with added power and more robust format support with its Burr Brown DAC and higher-end audio components. Gryphon combines the best features from both devices, and ups the ante across the board: more power, better Bluetooth quality and range, higher-spec components, broader format support, more inputs and outputs, and an overall bigger, better user experience.

Compared to Go blu ($299), Gryphon refines both wired and wireless sound quality. You can step further away from your source when connected wirelessly, and take advantage of higher-res format support, and even questionable software features like CyberSync if you’re so inclined. Both devices are tuned similarly, with a clear, crisp but still engaging and musical presentation, but Gryphon adds more note weight, definition and stage size, and is able to drive bigger and less sensitive headphones. Its sound shaping features and DSP filters are also more robust.

Where GO blu wins hands-down is ultra-portability, and the simplicity of being able to connect-and-forget while on the go, and sound performance is close enough to leave Gryphon at home and take GO blu on the road, even for longer trips.


Compared to HiBy RS6 ($1400), Gryphon takes a different approach sound-wise, being more neutral and transparent compared to RS6’s warmer, fuller and more organic tilt. RS6 does sound more natural with certain genres, especially with vocals, by virtue of its discrete R2R DAC, although Gryphon’s hybrid multibit DAC and features like the GTO digital filter get Gryphon really, really close in terms of naturalness. Gryphon also has more output power and a lower overall noise floor, even though both devices are hiss-free and more than powerful enough to drive all but the most stubborn headphones. In terms of absolute SQ, Gryphon matches RS6 blow-for-blow and is even slightly more advanced technically, with a wider stage and better clarity.

I’ve actually found the two to be complementary in the time I’ve spent with them so far, often using RS6 as my wired and Bluetooth source for Gryphon, especially when I want to use Gryphon’s extra output power. Another benefit of using the two together is connecting them using a balanced cable, effectively combining RS6’s excellent R2R DAC with Gryphon’s powerful, low-distortion amp.

Since RS6 is a self-contained DAP, it has its own advantages over a DAC/amp like Gryphon, not requiring external sources for one, and being able to navigate and manage multiple music sources from the device itself. If you’re after a standalone device for music playback and want to keep your music player, phones and computers separate, then RS6 is an excellent Segway from devices like Gryphon, but if sound quality is your only measure, you won’t lose anything with Gryphon and it’ll cost you significantly less.


I can highly recommend iFi’s brilliantly-made 4.4mm interconnect cable if you’re planning on tethering Gryphon to a balanced DAP or desktop amp – easily one of the best-looking, best-built and best-performing interconnects I’ve had the pleasure of using.


It’s been a while since I’ve used any of iFi’s larger portable devices, and I haven’t had the pleasure of trying out the newer xDSD and hip-dac series for that matter, but I’m confident enough to say that I don’t really see a use case for myself with any of them. Gryphon’s Bluetooth support and quality, for instance, makes the thought of using a wired-only external DAC/amp or dongle unpalatable at best. We’re fast-moving towards a time when wireless source quality will match wired performance, and with Gryphon (and GO blu to a lesser extent), the differences are already too small to warrant wired sources most of the time.

What hasn’t changed is our reliance on wired IEMs and headphones for maximum sound quality. Pairing Gryphon with a good pair of IEMs is the optimal use case for me, and the synergy with both the IE 900 and IER-Z1R is exceptional. But Gryphon is just as adept at powering easy-to-drive full-size headphones, like Sony’s MDR-Z1R. Unless you need the absolute portable freedom (and advanced features) of true wireless IEMs or headphones, you’ll get maximum sound quality with only a small loss in portability using Gryphon as a Bluetooth streamer for your wired IEMs, and if you want to get even more portable, GO blu.


Verdict and closing thoughts

When I first read about Gryphon, I didn’t quite see how it would fit for me, having switched to using IEMs exclusively, and using them exclusively with a DAP. It was GO blu that opened my eyes to the usefulness of a Bluetooth-enabled source for my wired IEMs, especially when I wanted to use my higher-end IEMs on the go. That’s when I joined the dots and fully understood Gryphon’s potential.

In one compact and still (for me) very pocketable device, iFi has evolved the concept of a portable Bluetooth streamer, bringing along all the advantages – and sound quality – of its upmarket wired DAC/amps, throwing in a few extra new and improved features in the bargain. For much less than the cost of a high-end DAP, you can now buy equivalent sound quality, better versatility, and enough power to drive not only IEMs but also full-size headphones, and still be able to move about freely with your music.

From the very first time I used it, Gryphon started changing the way I engaged with my music. For one thing, I credit Gryphon with encouraging me to re-look at getting a full-size headphone as an alternative to my IEMs. Then, using a smartphone with more ‘smarts’ and speed than any DAP, meant I didn’t have to skip a beat between the music player interfaces I’m already familiar with (specifically UAPP on Android).

With its outstanding Bluetooth input quality, I also wasn’t constrained by having to wire up the phone, and in fact, could even use the DAP as a source if I needed the phone for other tasks. And, when I wanted to max out sound quality, Gryphon includes everything I need to wire up my sources in the box.

iFi may have been a bit ambitious in claiming Gryphon as the ‘birth of a head-fi legend’, but I will say it’s easily the best portable device I’ve used in all my time as a portable audio enthusiast. That includes the flagship Lotoo and HiBy DAPs I’ve used in the past (and still use today), both in terms of sound quality but, just as importantly, flexibility, functionality and versatility. It liberates you from worrying about how to get your music in or out, which sources you can connect to, or which IEMs, headphones, or even speakers you want to use, without having to worry that sound quality and driving power will be compromised.

Sure, it had some teething issues, CyberSync being the most obvious and one that I suspect will still take some time to fully resolve. It has some missing parts – a case would be nice, and some stack loops too while we’re at it – and if someone at tech central could please fix the annoying AptX Adaptive ‘bug’ for me that would be much appreciated!

But these are hair-splitting gripes. Gryphon is just about the complete package, and I believe it’s only going to get better as iFi fine-tunes existing (and potentially new) features in firmware. Where it goes from here is anyone’s guess, but knowing iFi, there’s an upgrade path in development, if not already in production. As a version 1.0, Gryphon sets the standard for what’s possible in portable audio today, and I keenly await to see how the platform evolves in the future.

If, like me, you prioritise portability as much as you do absolute sound quality, and don’t want or need the extra headroom (and potential benefits) of full-size desktop gear, then Gryphon is an unequivocal must-buy. Highly recommended.

Full disclosure: @iFi audio sent me a sample GO blu in exchange for my honest review, and the opinions expressed herein are entirely my own. My review unit was supplied by AudioExchange, South Africa's official iFi reseller.

Introduction

iFi is no stranger to the head-fi community, having established itself over the past few years with a range of well-received source gear for almost any use case and budget. The UK-based company is actually a subsidiary of Abbingdon Music Research (AMR), one of the UK’s largest manufacturers of high-end audio systems, so when it comes to pedigree, iFi is not just another niche player or nameless mass-producer vying for a share of the limelight.

GO blu is iFi’s first attempt at an ultra-portable ‘dongle’, but unlike the majority of cable-tethered dongles from other brand-name vendors, Go blu is first and foremost a ‘hi-res’ Bluetooth dongle. That means it supports the highest Bluetooth codecs currently available, including Sony’s LDAC, which theoretically has enough bandwidth to stream hi-res music files (up to 24/96), albeit using lossy algorithms.

I’ve spent the past two weeks getting to know GO Blu more intimately, using it as my main DAC/amp (with my smartphone as the source), and comparing the experience to the higher-end DAPs I’m more familiar with. To say it’s been an eye-opening fortnight is an understatement; GO Blu has so far been one of the more pleasant surprises I’ve enjoyed in the hobby. Read on to find out why.


Tiny but mighty

The first thing that struck me about GO blu was not the stylish metal faceplate, Swiss-like chronograph, or practical non-slip rubber surround, but rather how small it was. By small I mean absolutely tiny – 54mm x 34mm and only 13mm thick. It’s also light, so light that iFi claim an AA battery is heavier, which is true by the way.

As tiny and light as it is, it still manages to house two headphone output ports, including a genuine Pentaconn-certified 4.4mm fully balanced socket. The chronograph – or ChronoDial, as iFi calls it – is the other striking feature. As far as I can tell, GO blu is the only dongle that features a rotary volume dial, though the ChronoDial is more than that, doubling as a click-button for pause/play, next/previous, and call answer/reject controls too.

There are two other buttons, one below the ChronoDial that’s used to switch between GO Blu’s nifty XBass and XSpace features (more on these later) and Bluetooth pairing mode, and one on the opposite side for power on/off and Bluetooth pairing confirmation. At the bottom of the case is a single USB-C port that doubles as a charging and digital data port (for wired DAC functionality), a small LED light for power state, and two pinholes, one for factory reset, the other for the built-in microphone (yes, you can make and take calls while connected with GO blu, although I didn’t try out this functionality myself).

The packaging is neat and simple, typically iFi-like with lots of information all over the box. A slide-out tray holds GO blu in its own cavity, with a small separate box for the included USB-C to A cable and velour-style carry pouch. I would have preferred to see a USB-C to C cable included considering GO blu is most often going to connect directly to a smartphone, and most modern laptops feature USB-C connectors too.

For the asking price of $199 a USB-C to lightning cable wouldn’t have gone amiss either, if only so that iPhone users would have one less thing to complain about because let’s face it, who wants to fall back on AAC?

But I digress; GO blu ships with everything you need to get up and running in the box. Build quality is excellent, and not just for the price, and the styling is unique and, if I may say so, quite stylish, more so than iFi’s usual utilitarian designs.


Swiss Army dongle

At the heart of GO blu’s functionality is a compact Cirrus Logic CS43131 DAC, which according to iFi is going to form the basis of their ultra-mobile product lineup. I can only assume there’s a good reason that iFi decided against using the traditional hybrid Burr Brown DAC that powers just about all their current devices, and if I had to speculate it’s probably because they were aiming for a much lower power draw than was possible to achieve with the standard DAC.

As it is, GO Blu’s 450mAh lithium battery supplies up to 8 hours’ runtime, depending on the headphones used and processing requirements, which is plenty for all-day use, considering it only takes an hour or so to charge it back up to full. Since GO blu also uses its battery in tethered mode, you can maximise sound quality from your phone by wiring it up without draining the phone’s battery, something many other dongles don’t offer.

GO blu incorporates the same dual-mono fully balanced architecture common to many of iFi’s recent portable products. This not only helps clean up the signal, but also provides much more power to drive even demanding headphones – up to 245mW into 32 ohms to be exact. You’ll struggle to find this much muscle in any other dongle in this price range, and even more expensive (and less portable) amps generally don’t go this high either.


Ironically the additional power seems to have caused some teething issues for early adopters, with reports of some GO blu units emitting unacceptable levels of amplification noise, especially with sensitive IEMs. In my own testing, I’ve found no such issues with my particular unit and my IEMs, so it’s likely more a factor of quality control than it is a design flaw, or at least I hope that’s the case.

Other amplification features making their way into GO blu’s spec list include DirectDrive, which eliminates the coupling capacitor typical in many circuit designs to provide a more direct signal path that, supposedly, helps further eliminate noise and reduce distortion. The capacitors that are included are sourced from TDK and MuRata, much like those used in ifi’s more expensive desktop-grade devices.

Also adapted from other iFi designs is analogue DSP functionality, which in GO blu take the form of XBass and XSpace effects. XBass, as the name suggests, helps fill out the lower octaves with a subtle dose of extra weight, an effect I can heartily recommend even if you’re using bass-savvy IEMs or headphones. XSpace is less convincing, adding a touch of air and pseudo ‘space’ to the sound, which could be useful if you’re using intimate-sounding headphones. You can also use both effects together, but I tend to just leave XBass on and forget about it.

The last arrow in GO blu’s sizeable quiver is a Qualcomm QCC 5100 Bluetooth controller. This brings GO blu up-to-date with the latest Bluetooth 5.1 receiver spec and supports almost every conceivable Bluetooth codec, including AAC, SBC, aptX, aptX HD, aptX Adaptive, aptX LL, LDAC, and LHDC/HWA. Conspicuous in its absence is Qualcomm’s newly- announced AptX Lossless codec, although I don’t believe there are any devices that support this codec at the time of writing.


Sound impressions

With so many features and so much power in such a miniature space, iFi has taken a leap of faith that all these moving parts, figuratively speaking, will click together to deliver a quality audio experience on the go. The combination of hi-res Bluetooth and 4.4mm output makes GO blu particularly potent for users of higher-end and higher-power IEMs and headphones.

I decided to test GO blu by using it exactly how I expect most people to use it: first, with Bluetooth and a smartphone, and second, wired to a laptop. All tests were done with a pair of Sennheiser IE 900 IEMs using the 4.4mm balanced output.

My playlist included tracks by Lana Del Rey, Beyries, Angel Olsen, Ane Brun, Max Richter, Def Leppard, Brandi Carlile, Britney Spears, Linda Ronstadt, Eagles, Lola Marsh, Cranberries, Carpenters, and a host of other obscure indie singer-songwriters I won’t list here. I mention these only because my taste in music will likely differ from yours, and it’s important to remember that my impressions will be biased to my preferences accordingly.


As a Bluetooth receiver

To be honest, I was skeptical about using Bluetooth for serious listening. While I’ve experienced exceptional power and quality from tiny dongles before (EarMen’s Sparrow comes to mind), this is the first time I’ve gotten to hear just how far we’ve come with wireless in the mix.

The Sony WF-1000XM4 true wireless IEMs are my go-to for ‘casual listening’, with a smooth, punchy and inoffensive sound I can listen to with ease all day long. But when I want a more involved listen with better quality throughout the playlist, I generally turn to more capable (and correspondingly more expensive) IEMs like the IE 900.

Unlike TWS, GO blu relies on Bluetooth for input only, since all the digital conversion and amplification happens internally. That makes a Bluetooth dongle very different to TWS IEMs, which rely entirely on the tiny DACs and amps built into each earpiece for sound processing. It’s a distinction I feel is important to make, in case you’re thinking there’s little difference between the two, even though they both use Bluetooth in the chain.

Pairing GO blu to an LG V30+ phone was a quick and simple process. Switching the blu on for the first time automatically puts it into pairing mode (denoted by alternating blue/red LEDs on the top panel). Once paired, it’s important to select ‘Best Quality’ under the pairing’s Bluetooth settings – if your phone doesn’t select that option by default – else you may get paired using AAC or worse, SBC.

Note that if you’re an iPhone user, AAC and SBC are your only options, so this only applies to Android users. Most modern Android phones should support the LDAC and/or LDHC codecs, so make sure that’s how you’re connected before proceeding. If you’re unsure which codec you’re paired with, double-click the button on the left panel, and a sexy voice will reveal the codec and bitrate (‘LDAC 96 kilohertz’ is what you want to hear).


My very first thought at hearing the opening verses of Lana Del Rey’s Video Games though GO blu, streaming over LDAC from my trusty LG, was a distinct sense of familiarity. This was not the sweet but smoothed-out sound of the Sony TWS IEMs; this was very much the same tone, same texture, same quality I was used to hearing from the IE 900 plugged directly to my phone, to the Sparrow, or to just about any other excellent, amplified source.

Instrument timbre is as good as I know the IE 900’s timbre to be, and layers beautifully with Brandi Carlile’s smoky vocals in The Story. Overall tonality is neutral with a hint of warmth, very much as I expected from an iFi device. This has been the ‘house sound’ since my first encounter with the venerable Micro iDSD more than four years ago, although I find the GO blu to be slightly more transparent and airier by comparison, if memory serves.

Male vocals are delivered just as deftly as female, Don Henley’s iconic performance of Hotel Californiaperformed live on the Eagles’ Hell Freezes Over a case in point. GO blu takes firm control of the IE 900’s powerful dynamic driver, pushing punchy, bouncy bass notes that hit with authority, and more complex passages like crowd noises and guitar duets are never muddied or overwhelmed, even though I can pick out a hint of smoothness that probably shouldn’t be there in some raspier vocals.

While not the most technical high-end IEM I own, the IE 900 is still very technically adept, with a generous stage, excellent layering and separation, and fairly precise imaging. To my ears none of these are hamstrung to any significant degree by GO blu as a Bluetooth dongle. It may not drive the IE 900 as precisely and expansively as the HiBy R8, for example, but the difference is far smaller than the $1800 difference in price between the two would suggest.


As a wired dongle

I have to take issue with iFi for ‘crippling’ the Cirrus DAC by limiting its maximum supported resolution to 24/96, not enabling native DSD support, and not even contemplating MQA support. I suspect these were conscious choices made by the company to either maximise battery life or reduce size and cost, but at the very least the very capable DAC should have been allowed to do its thing with PCM?

Regardless of the reasons, when I connected GO blu to my MacBook Pro, these limitations were clearly displayed in Audirvana’s control panel. However, it didn’t stop GO blu from continuing to show off with its crisp, clean delivery. Linda Ronstadt’s evocative vocals in Dreams to Dream made me tear up like a baby – as they always do when the delivery is spot on – and with GO blu, it was absolutely on the mark.

Switching to something more modern and poppy, Britney Spears’ If You Seek Amy was a bassload of fun, complete with sketchy sample quality and imperfectly recorded vocals. If nothing else this speaks to GO blu’s transparency as a source, because it’s exactly how I know this track to sound with the IE 900. The slight injection of warmth is welcome, and I could swear this is some of the best bass weight I’ve heard from the IE 900.

Replaying some of the tracks I heard wirelessly, I could try to make a distinction between the two, but I’d probably be off-target half the time. What struck me more than anything was how much fun it was to work and play with the MacBook Pro delivering insanely good sound quality with nothing more than a little dongle dangling from the USB port. I could AB and pick out minor differences here or there, but really, why?

It’s not all roses though. For example, I struggled with figuring out how which device – GO blu or MacBook – ultimately controlled volume. Turning the volume of the ChronoDial changes the volume on the Mac, but sliding the volume up or down in Audirvana leaves the ChronoDial setting as-is. Also, I can only raise the volume about 10-15 percent on Audirvana before the IE 900 becomes too loud. There’s probably a setting in Audirvana or the Mac itself that I haven’t studied properly, but out of the box, it’s unnecessarily complicated compared to Bluetooth mode.

Also, it seems I can’t pause/play or skip tracks using the ChronoDial when in wired mode. I’m not sure that’s even an option, but if it’s not, that’s one less useful feature you lose when you wire up.


Closing thoughts

GO blu appeared out of the blue, so to speak, not really aligning with anything iFi has done in the past, and yet when you use it, it makes perfect sense. It’s the ultimate expression of iFi’s portable DAC/amp philosophy – an ultraportable device that gives up very few features iFi users almost expect by now, like analogue DSP, sophisticated amplification, and a well-tuned, well-specced DAC untethered from the desktop and able to drive almost any mainstream headphone.

The killer feature, for me, is Bluetooth. It’s such an obvious feature I’m actually surprised so few of the many dongles flooding the market right now actually offer it. Considering how good GO blu sounds in Bluetooth mode – so good, in fact, that wiring it up makes a small but arguably insignificant difference to sound quality – and it almost doesn’t make sense that dongles don’t offer wired mode as an option instead of default.

That said, GO blu isn’t perfect either. While my own unit, with my IEMs, has no audible hiss or hum during playback or between tracks, but there are enough reports out there that suggest it’s not ideal for all IEMs, and that QC could be an issue. It also lacks many features that iFi have either purposefully withheld to optimise battery life and performance, or perhaps ‘cleverly’ withheld so as not to cannibalise other products. After all, if they gave us IEMatch and their famous Burr Brown DSD-capable DAC, there wouldn’t be much sense in spending twice as much on a device twice the size and harder to carry around, right?

But cynicism aside, I’m excited by GO blu, even if it is version one-point-oh. It’s already ‘better’ than any other dongle I’ve used by virtue of its ultimate Bluetooth portability and infectiously-good sound quality. It’s well made and seems to be fairly stable, and with any luck, iFi will see fit to add to the current features with future firmware updates. Best of all, it takes the IEMs I know and love, and drives them with a steady hand, infusing its own very subtle character but really just allowing them to do what they do best.

I can think of no better endorsement than the fact that, for two weeks, I’ve been using a $200 dongle instead of a $2000 DAP and haven’t for a minute felt poorer for it. GO blu is an easy recommendation from me.

It’s not often that one gets to meet a real celebrity; someone whose fame cuts right across cultures and households. In the real world, names like George Clooney and Julia Roberts come to mind. In the head-fi world, few are more famous than Utopia.

Focal’s flagship dynamic headphone has only existed for about two years, and yet ask most headphone devotees to name the headphone that sits right at the top of the tree and many, if not most, would say Utopia. That’s partly a consequence of the hype train that rolled into town when the French audio maker unveiled the double-whammy of its high-end dynamics, the ‘mainsteam’ Elear and flagship Utopia, and partly because of Utopia’s eye watering price tag of $4,000 at a time when most statement headphones were still selling for half that, or less.

Fast forward to today, and the Utopia is still the headphone I associate with the exclusive ‘summit-fi’ tier of head-fi audio equipment that only a select few enthusiasts can afford, let alone experience. As an enthusiast myself, I could never have imagined my climb up to the higher echelons of this devastatingly expensive but supremely enjoyable hobby would be so swift, and yet the headphone gear I now use and consider my ‘endgame’ is probably sat at Camp 2 or 3 compared to Utopia’s Everest summit.

The Utopia in person

As an Elear owner I am intimately familiar with Focal’s headphone design and ergonomics, so seeing the Utopia for the first time was pleasantly unsurprising. I’ve read reams of reviews and participated in many discussions with Utopia users, but there was still a feeling of privilege handling and opening the large display-style box the Utopia was housed in. Not dissimilar to the Elear’s box, it was black and bulky, but finished with a matte black skin and red trim that imparted an understated sense of prestige.

The Utopia itself was, as expected, very Elear-like, though it felt slightly lighter in the hand. The leather finish of the headband and earpads is uber-soft, clearly made of a much finer grade of leather than the excellent Dekoni Elite sheepskin pads I use with my Elear. The memory foam is also much softer, though not as soft to the touch as the suede-like Elex pads I use as an Elear alternative (more on that later). The Utopia’s carbon fibre yokes have enough flex to sit the cups comfortably on your ears, but unlike the Elear the yokes and headband don’t creak when twisted.

The latter isn’t an issue for me personally - there’s no creaking when the Elear is worn - but it does show the extra level of detail and build quality that went into the Utopia’s design, despite the similarities of look and feel with the Elear, that bestow it with its flagship status.

On the head, the softness of the Utopia’s leather translated to added comfort, and despite not having a suspension strap (an oversight in heavier headphone designs), the headband didn’t immediately leave any hotspots on top of my usually sensitive scalp. It doesn’t exactly ‘disappear’ when worn, but it also doesn’t feel like you’re wearing a motorbike helmet, a-la the Audeze LCD-3.

First impressions

I’ve been anticipating Geoff’s visit all week, and so diligently prepared a list of test tracks I was hoping to hear through Utopia, running the gamut of my musical preferences from girl with guitar to male crooners, modern pop, classic rock and electronica.

First up was Heidi Talbot’s intimately beautiful ‘If You Stay’ (watch here) from her Love+Light album, a track I’ve listened to countless times with almost every headphone I’ve owned and auditioned. Heidi’s innocently sensual voice and breathless delivery lend the song an ethereal quality that can sound edgy with the wrong headphone and compressed when the source is too digital. There was never any risk of that happening with Audio-gd’s exemplary R-28 all-in-one ladder dac and headphone amplifier, and even though the Utopia was using the amp’s single-ended output (I unfortunately did not have balanced Utopia cables to experiment with), the analog-like qualities of the source were immediately apparent.

‘If You Stay’ starts off with a series of lower register guitar plucks that should, ideally, reverberate and resonate around your head, and give the simple intro a sense of palpable weight and warmth. That’s exactly how Utopia delivered it, with every nuance of the guitar clearly and crisply articulated. Heidi’s opening verse was perfectly separated from the instruments that continue to play around her, and I could immediately get a sense of both depth and intimacy, as if she were sitting in the same room, singing her song to me.

Having said that, the Elex is no slouch, and so having ‘calibrated my brain’ by first playing the track through the Elex, I was left a little underwhelmed when the Utopia hardly deviated from what I’d just heard, minutes before. In a blind test I would be hard pressed to tell which headphone was which, other than the obviously cooler Utopia pads around my ears.

Similarities aside, the reason I keep going back to this expertly-mastered track is because good gear will almost always render it correctly, and any deviation is a solid strike against. So far, so good, but the first view from the summit was one I’d already seen before. Also, you may have noticed I used Elex to describe the Elear above, because having switched to Elex pads, that’s exactly what the Elear becomes. Since the Elex has a very similar FR graph to Utopia - and is often described as a ‘baby Utopia’ - I wanted to compare apples with apples, rather than use the more strident, dynamic and punchy Elear.

Change of pace

Strident, dynamic and punchy was exactly what I was looking for from the second test track, AC/DC’s seminal ‘Thunderstuck’ (watch here). Again a gorgeously mastered track, with good gear you should be able to get a real sense of stage width and space as the iconic guitar riff slowly builds up and around you, followed by the ‘kick’ of the kick drums - even before Brian Johnson’s unique delivery is heard over the backing vocals. Being treble sensitive, I use this track to test for glare in the higher notes of the screeching guitars, and as a bass aficionado, I want to feel the drums in the mix, not just hear them. This isn’t always an easy trick to pull off with headphones, but the really good ones will find just the right balance, even at higher volumes, without causing fatigue.

The three most obvious qualities immediately apparent in Utopia’s presentation of the track was its remarkably clean highs, superb instrument separation and ink black background. The sound appeared ‘out of nowhere’ and disappeared from the stage with equally stealth-like speed. I’d read all about the Utopia’s fabled ‘speed’, but didn’t really understand what that meant until I heard this track. You could almost slice the details with a scalpel, but at such speed that it would be humanly impossible to do so. The fastest headphones I’d heard prior to this was a higher-end Stax electrostatic, and this was every bit as fast if not faster.

Speed isn’t the only trait the Utopia seems to share with electrostatics. Not known for moving much air, ‘stats specialise in the delivery of tight, clean and detailed bass that often lacks the weight of real instruments or the rumble of electronic drums. This was a disappointment when hearing my first Stax, and likewise when hearing Thunderstruck through the Utopia. While not specifically a bass-driven track, I’ve heard the kick drums in the intro and the cacophony of drums in the body of the track conveyed with a real visceral impact on the likes of ZMF’s Atticus and the LCD-3, and even the Elear has a certain dynamic punch that makes Thunderstruck’s kicks stand out in the mix. The Utopia, while perfectly articulate, just didn’t do that for me. It was almost a sanitised rendition of bass, like one might expected from the likes of a Sennheiser HD600 or HD650, albeit a touch fuller than Sennheiser’s midrange models, and certainly more detailed.

But where you sometimes want to let your hair down and rock out to a track like Thunderstruck - or similarly styled tracks like Joe ‘Satch’ Satriani’s ‘Always With Me, Always With You’ (watch here) off his ’Surfing With The Alien’ album - you’re more likely to sit and clap to the beat while tethered to the ‘oh so polite’ Utopia. And that’s ok; the Utopia is not, as far as I can tell, a balls-to-the-wall headphone, and that’s by design. There’s just too much detail, nuance, and subtlety in its approach to really bring on the grunge. For many audiophiles that’s a plus, and my penchant for tastefully elevated bass isn’t something these folks will lose much sleep over.

It all comes together

Normally when I audition a headphone, lack of impact is one of the first things I notice, at which point I generally lose interest. But the Utopia was doing too many things too well for me not to pay attention - including the way it described rather than viscerally delivered the bass in the mix. Owl City’s electronically layered ‘Saltwater Room’ literally invited me to walk in and explore the different points of sound emanating all around the space Utopia created. Every layer was separated like an onionskin at the hands of a master chef, and expertly arranged so that the parts were never removed from the whole. On brighter headphones that lack a sense of nuance or control, the sweetness of Breanne Duren’s supporting vocals - which really steal the show from lead singer Adam Young - can be lost in the mix. Instead, the Utopia let me meander through the treble-laden track as if it were lush and rolling midlands, with Adam and Breanne walking with me and around me. It was quite magical really, and prompted me to write in my notes: “best treble I’ve heard in a headphone.”

Cohesiveness is probably the defining character of this headphone. Whether your leaning is more synthesised like Owl City and Daft Punk, or soft rock like Def Leppard, the Utopia presents you with a sound that is both richly detailed and highly musical, without favouring any parts at the expense of others. It’s impossibly smooth, lush and clinical all at once; and unwaveringly musical to my ears. Unlike other high-end headphones that specialise in doing some things well - the space and resolution of the HD800, the speed and transparency of the Stax, the warmth and weight of the LCD-3, the natural realism of the Auteur - the Utopia takes all these elements and melds them together into its own unique sound.

Of course it’s not without its faults, small as they may seem at these dizzying heights. Daft Punk’s ‘Contact’ (listen here) from their masterpiece album ‘Random Access Memories’ is a typical slow-burning, quickly building piece of artful electronica that goes from spartan emptiness to crazy mayhem in a few short minutes. There’s a frantic energy conveyed by the sudden advance and attack of the ‘aliens’ that Utopia’s measured approach somehow fails to grasp. With all the elements neatly intertwined, it almost holds itself back from giving any of the crazy effects prominence over another, but that’s exactly what you want to hear, and many less poised headphones will give you just that.

Utopia is also too fast, in my opinion, at conveying decay, which can make it sound a little dry at times. The droning decay of the deep drums that softly underlie Katie Melua’s ‘Red Balloons’ is a case in point, as are the big, bold booms in Dadawa’s ’Sister Drum’. In both cases Utopia lets you know what you’re hearing - heck it’s so detailed you can probably read the label on the backing material of the drums used in the track - but the size is all wrong. Perhaps it is Utopia’s expensive and exotic Beryllium drivers at play; the Elear and its equally sized drivers doesn’t seem to have too much trouble with the drums in those tracks. It could just be that a buttery smooth rather than hard edged articulation is exactly the sound Focal was seeking, in which case they’ve nailed it.

Back on terra firma

Later that day, after my climb down from the summit, I was reflecting on the experience with my brother, who’d extensively listened to the Utopia in days gone by. In his own words, “the Utopia’s refinement has an incredible way of dissecting the music yet presenting it in an incredibly musical way, so it is articulate all the while being delicate and pleasing, and not sanitised like so many ‘audiophile’ headphones.”

I couldn’t have said that better myself, so I didn’t. What I will say is that, combined with the right system, the Utopia earns its praise and position among the very best of the best. While I consider my system to be of a very high standard, there’s no question a headphone like Utopia will benefit more - and give you more - from a system more commensurate with its price tag. That’s not to say the system I’m using was necessarily a limiting factor, but that there are more gears to be shifted if you have the means to do so. Add to that the mysterious effect that synergy may yield with different components, which Utopia is undoubtedly transparent enough to respond to.

Closing thoughts

Which brings me to the reason I decided, in the end, to take leave of the summit, regardless of how stunning I found the view. Truth be told, the difference between high-end and summit-fi is not nearly as large as you’d imagine based purely on how much it will cost you to walk those extra few steps to the top. If, like me, you’re willing to spread your listening between two or more headphones, each of which does something different or better than the other and is therefore more suited to different types of music, then putting all your eggs in one very expensive basket like Utopia is not necessarily the best way to spend your money.

Then again, if money is no object, and the price of Utopia doesn’t make your palms sweat and eyes twitch, then few headphones I’m aware of can elevate your music to extreme levels of fidelity like Utopia can. It may not get you up and dancing, but it will make you cry - and not because you had to sell your car to buy it.

Full disclosure: HiBy sent me a review sample of the RS6 in exchange for my honest feedback and a comprehensive review. No other expectation was made of me, nor any deadlines set to deliver. They were also fast on the draw to sort out some technical issues that befell my particular unit, and I’d like to extend a special mention and thank you to @Joe Bloggs who was instrumental in making it happen. That said, the opinions expressed in this review – for better or worse – are entirely my own.

If you haven’t read my first impressions overview of the RS6, please take a few minutes to do so now, as I’ll try not to repeat too much of what I already wrote.



Preface

Without pulling any punches, the HiBy RS6 heralds a new dawn for DAPs.

It is the first-ever DAP built on relatively current hardware and an open Android software platform that features a fully discrete non-oversampling resistor ladder (R2R) DAC. This is a significant technical achievement given the inherent difficulty of engineering discrete R2R technology into a device the size of a deck of cards – especially considering all the other components that need to fit in alongside the actual DAC.

But overcoming technical hurdles is one thing; what most DAP buyers care about is how good it sounds, and how well it performs the various tasks a modern Android DAP should be able to perform. In that regard, the achievement is arguably even more impressive, because frankly, the RS6 aces both.

You may already be familiar with other HiBy DAPs like the R8 and R6 2020, both of which have essentially the same hardware and software platform (other than the new R2R-related stuff), in which case feel free to skim over the big chunk of the review that covers the software, and make your way to the Sound Impressions section.

But if you’re entirely new to Android DAPs in general and HiBy in particular, I encourage you to read through the Setup and Software and Personalising the RS6 sections in more detail, as I feel that’s where a large part of the value of the RS6 ‘experience’ resides. We can always debate the importance of the experience of using a DAP later, but in my opinion, it goes hand-in-hand with sound quality and IEM pairing.



Introducing the RS6

The RS6 is the first in a new series of DAPs based on HiBy’s so-called ‘DARWIN’ architecture. I’m not sure why that particular name was chosen, or what it stands for, but I assume it’s meant to evoke the idea of evolution. While R2R is not new, and in fact predates the more commonly used Delta Sigma DACs used in most modern DAPs, DARWIN is less about R2R and more about the flexibility and configurability of the system as a whole.

DARWIN’s biggest selling point seems to be how easily it allows users to tweak the sound to their preference. This is enabled by a series of technologies, including:

A 256-tap adjustable finite impulse response (FIR) filter. This is the core technology used to configure different aspects of sound, including noise-shaping filters, oversampling of the input signal, and tweaking the sound to suit different brands and makes of IEMs. In a nutshell, it provides a nifty way of tweaking the sound with various filters without any loss in sound quality.

Switchable Non/Oversampling. The ability to convert digital signals to analogue sounds without oversampling is – theoretically at least – the most accurate way to preserve the musicality of what you’re hearing, for a more, er, analogue presentation.

DSD bypass for native DSD decoding. By their very nature, R2R DACs cannot process 1-bit DSD signals (that’s the preserve of Delta Sigma DACs). Most R2R DACs either don’t provide any support for DSD formats, or internally convert DSD to PCM before sending them to the DAC for processing.

The RS6 has a separate dedicated 1-bit DSD processor that natively handles DSD files before sending them to the amplification stage for output. Whether or not it completely bypasses all R2R circuitry is unclear. Most playback software will also allow you to convert DSD to PCM on the fly, and therefore make full use of the R2R DAC and its features. I’ve done some testing to at least validate what I’m hearing in the Sound Impressions section below.


Everything else about the RS6’s software platform is basically a copy/paste of the Delta Sigma-based R6 2020 released last year. This includes:

• Full 16x hardware-based MQA support, the highest MQA level of any current DAP;
• HiBy’s Direct Transport Architecture (DTA), which now includes Android bypass for bitperfect output via USB;
• HiBy OS, a highly-optimised UI and underlying OS based on Android 9 with full support for Google Play Services; and
• HiByLink, which gives you full control of HiBy Music software via the same software on your smartphone.

Powering these technologies is the same hardware platform that remains, at the time of writing, the fastest available on any DAP at any price:

• Snapdragon 660 SoC, based on a 2.2GHz 8-core Kryo 260 CPU and an Andreno 512 GPU,
• 4GB RAM and 64GB solid-state internal storage;
• Dual wideband 2.4GHz and 5GHz Wi-Fi;
• Bluetooth 5.0 (transmitter and receiver) with UAT, LDAC and AptX HD support, among others; and
• Full-speed USB 3.1 connectivity.

Externally the RS6 is a facsimile of the R6 2020, at least by way of form factor, screen, and input/output ports:

• 1080P (443ppi) 4.97-inch IPS screen;
• 3.5mm single-ended and 4.4mm balanced headphone ports and a separate set of matching size line-outs;
• USB-C power and data port;
• 4500mAh battery (up to 8 hours playback, less when playing back hi-res files and DSD);
• Angled back, pause and previous buttons;
• LED indicator that changes colour based on charging state and playback bitrate; and
• Micro-SD card slot supporting cards up to 2GB.

It also features the same knurled volume dial on top of the player, which I must say is irritatingly small and fiddly, especially with the leather case in place. At least the dial turns with discernible clicks, unlike the R8’s smooth yet somewhat laggy volume dial.


What has changed with the RS6 is the build material, switching from the R6’s aluminium frame to a copper or copper alloy material supposedly better suited to heat dissipation. The copper has been plated in a rose gold finish that at first was a bit too feminine for my liking, but over time has grown on me. I still prefer the all-black matte finish on the R8 though. One result of the switch is an increase in weight to 315g, about 100g heavier than the R6 2020 but still significantly lighter and slimmer in dimensions than the R8. If you’re after a pocketable DAP, the RS6 will fit very nicely indeed.

Both the back and front of the RS6 are made from Corning Gorilla Glass to prevent accidental scratches, but HiBy provides pre-installed screen protectors on both sides just in case. The back also features a new carbon fibre inlay pattern, which good as it looks, disappears the minute the leather case slips on.

Speaking of which, HiBy includes a free tan-coloured leather case that appears to be slightly better designed than the cases provided for the R6 2020 and R8, but not nearly as nice as the limited edition Dignis case supplied with early editions of the R8. I got my unit with an emerald green case that HiBy sells separately for $80, which is probably worth it if, like me, you prefer the green to the tan (though I admit $80 for a case is excessive).

There’s also a much cheaper ($22) third-party aftermarket silicone case that’s become popular among R6 2020 users and which is said to provide a better grip and an overall better fit. I’ve ordered one myself from here, although it hadn’t arrived at the time of writing.

The only other accessories in the box are two cables: a USB-C to USB-A charging and data cable, and a custom HiBy USB-C to coaxial cable for digital output to an external DAC. Both cables look to be of very high quality indeed, as does the overall packaging presentation. I covered the unboxing in some detail in my first impressions overview so won’t repeat it here, except to say that you should take care when opening the box for the first time as the top part of the package (housing the cables) tends to fall straight out as soon as the two halves of the box are pulled apart.


Setup and Software

The RS6 is a full-featured open Android DAP, meaning it’s based on the same software ecosystem that powers most modern smartphones. While it’s not a smartphone, and isn’t intended to be used as one, it can perform many of the same functions, using the same apps.

The first time you switch on the RS6 you’ll be asked to specify a language, then a time zone, and a few seconds later, after sitting through an all-new DARWIN bootup animation, you’re in.

The landing page, also adorned in DARWIN-themed regalia, is fairly spartan. At the bottom of the screen is a launch bar with five icons – not your usual Android icons, but rather HiBy’s customized Darwin designs. From left-to-right there’s an icon for Snapdragon Gallery, File Manager, HiBy Music, Via (whatever that is), and Play Store.

Pressing the app drawer icon reveals four more preloaded apps: Calculator, Clock, Files and Settings. Swiping down from the top of the screen reveals the editable quick launch bar, with icons for Wi-Fi, Bluetooth, Auto Screen Rotation, 180-degree Screen Flip, Audio Settings and DARWIN Controller. Drag down and you’ll get a few more options, like screen brightness control and gain level settings. The only other visible information on the screen is the status bar on top, showing time, volume level, output used, Wi-Fi status, sample rate (when active), and battery level.

Of all these ‘apps’ and options, the only ones you actually need to configure the RS6 are Settings, Audio Settings and DARWIN Controller, so let’s briefly work through the different screens so you know what’s what before I flip the script and show you how to really take control of this DAP.


Settings

The RS6’s Settings section is where you get most of the configuration work done, connecting you to Wi-Fi networks and Bluetooth devices, setting battery limits, customizing display elements, and tweaking security and accessibility options, as just some examples. Without going section by section, here are the most important configuration options you should consider:

Wi-Fi (Network & Internet). Unless you’re not going to use the Play Store, or stream, or do anything with the RS6 that requires Wi-Fi – in which case I have to ask, why did you even buy a Wi-Fi-capable DAP? – connecting to a Wi-Fi network or hotspot is the first thing you’ll want to do, as it basically leads into everything that follows.

Bluetooth Settings (Connected Devices). If you need to pair Bluetooth headphones, this is where you go to pair them. Also, if you want to set up the RS6 as a Bluetooth DAC/receiver, Bluetooth Audio Input is what you’re after.

Default USB configuration (Connected Devices). This option lets you set up the RS6 as a USB DAC with the option of charging it at the same time, or disabling power input for a cleaner signal. You can also put the RS6 into file transfer mode for connecting it directly to a PC or Mac.


Apps & notifications. This is where you go to mess around with installed apps, set their notification status, and set default apps for the home page and web browsing, among other tasks. The only time I’ve had to use this option was to disable certain apps, like HiBy Music (more on this later).

Battery. This is an important option for one key setting: Max battery. It’s a good idea to set this to 80% or 85%, and as long as you’re charging the RS6 while it’s powered up, it won’t charge to more than the set limit. This sort of works, with my maximum setting of 80% usually exceeded by a few percentage points, but it’s no biggie. Just make sure Idle shutdown is switched off, or else the RS6 will go into sleep mode and charge to 100%.

Display. Feel free to mess around with your display options here, the most important of which is setting the Ambient Display to show New Notifications (useful for showing new track titles when they start playing while the screen is off), and keeping the LED light on when powered on (to see when playback is active or stopped while the screen is off).


Security & location. This is a strange place to put the toggles for activating or deactivating the volume dial and navigation buttons when the screen is locked, but it’s where you’ll find them. You can also set other useful options from here, like Lock screen preferences and gestures. I also enable Find My Device.

Accounts. This is where you can set up new Google accounts or activate existing accounts, useful if you’re going to use the Play Store. If you want to tweak specific account settings, go to the Google option a few rows down.

Gestures (System). The only thing you need to check here is that Double click wake up is on, considering how important this is for overall usability (trust me). Later on, I’ll show you how to enable double tap to lock screentoo, so stay tuned. Another feature I enable from here is Swipe up on Home button. This discards that ‘old’ 3-button navigation control in Android and replaces it with a more modern multifunction button and context-sensitive back arrow.


System updates (System). This is an important option for checking that you have the latest firmware installed, although if you’re regularly connected to Wi-Fi you’ll be automatically notified when a new firmware version becomes available.

Build number (About device). This is a trick I learned early on in my Android journey. Click on Build number 7 times to enable a ‘hidden’ Settings menu called Developer Options, from which you can set all manner of hidden attributes, like Bluetooth codecs, USB debugging, and other potentially useful features. If you don’t need these, leave it alone.

Audio Settings

Now that you have the Android system and usability functions set up to your liking, it’s time to configure the music playback options. You’ll find all the important options in the Audio Settings menu as follows:

Gain: low, medium, high. I’ve set all my DAPs to high by default as I find it gives me the most dynamic sound, at the small cost of less play on the volume dial. The RS6 doesn’t have the R8’s Turbo option, but I find that High Gain drives my IEMs louder than the High Gain + Turbo setting on the R8, even though the RS6 has half the power output of the R8.

Plugins: developed by our good friend @Joe Bloggs, you have the choice of downloading three plugins: Convolution (misspelled Convlution), Sound Field (misspelled Sound Filed – come on HiBy!), and Balance. Of these, I’ve only ever tried the Convolution filter, which lets you play around with various custom profiles on 44.1kHz PCM files. Personally, and with all due respect, unless you’re a serial tinkerer, leave these well alone.

MSEB: another genius piece of software written by Joe, this one is absolutely useful. It’s also the only system-wide EQ software I’m aware of for Android that works seamlessly with any application at any bit-depth, other than MQA (which can’t be EQ’d by design). If you’re unfamiliar with MSEB – or Magic Sound 8-Ball as it was previously known – it’s a unique take on EQ in that it allows you to tweak actual audio elements, like temperature, bass extension, note thickness and sibilance, rather than using preset frequency bands.


The latest version of MSEB gives you more granular control of each element, adds + and – buttons for easy one-click adjustments, lets you choose from three preset tuning styles, and also adds the ability to import custom tuning files from other users. In my experience, MSEB leaves sound quality intact while allowing for subtle to not-so-subtle changes to the sound. It’s particularly useful for when you have minor issues, like moderate sibilance, with one of your IEMs or on certain types of music, which can now be fixed with a few quick clicks, irrespective of the app or streaming service you’re using.

There are three other sliders in Audio Settings you might find useful:

DSD gain compensation, for adding volume to DSD playback, considering many DSDs are mastered at lower-than-normal volume (I set this to +6dB by default).

Channel balance, for adjusting left and right channel volume balance, useful if your hearing is stronger in one ear or the other, or if your IEM has a slight channel imbalance.

Max volume, for setting the maximum allowable volume. This is a critical setting, and I recommend everyone sets maximum volume to 50% to prevent accidentally swiping the on-screen volume slider to 100% with IEMs plugged in (I’m speaking from painful experience).

DARWIN Controller

This is an all-new menu option for the RS6 (and presumably future RS devices) and allows for some very interesting fine-tuning using adjustable filters in the audio chain. That said, other than switching between NOS and OS, I can’t hear any changes to the sound, even subtle changes, when changing any of these filter options. This includes:

Low-pass antialiasing filters, labeled Darwin Default and Darwin 1 through 10. Regardless of filter, the sound stays the same, or maybe my hearing just isn’t acute enough to resolve the change.

Atmosphere Enhanced. I have no idea what this does, but like the low-pass filters, makes no perceivable change to what I’m hearing.

Customized Presets. This offers selectable filters for 19 current and legacy IEMs from the likes of QDC, Softears, Unique Melody and 64 Audio, but try as I may I can’t hear the difference with my own IEMs, which aren’t on the list.


I can only assume HiBy will build more options into the DARWIN Controller as the platform evolves, but for now, I consider it a curiosity more than a valuable resource.

Personalising the RS6

Settings aside, the real power of an Android DAP is what it allows you to do with software, specifically apps. The RS6, like other current high-end open Android DAPs, lets you run basically any app you can think of, which I consider both a blessing and a curse.

It’s a blessing because I can pick and choose which apps to use for the most important DAP functions for my use case: music playback, streaming, and file management. But it’s also a curse because it unlocks a smorgasbord of compelling apps that I could be tempted to try, even though I don’t really need them.

In this section, I’ll cover some of the most important apps I use on the RS6. If you’ve read my R8 review you’ll already be familiar with these apps, which work in exactly the same way on the RS6. To save you time, the information below is lifted almost verbatim from that review.

Launcher

The first step to customizing the RS6 requires taking control of the landing page, lock screen and overall appearance of apps and notifications. The easiest way to do this is with a Launcher app. My Launcher of choice is Nova Launcher, available as either a free (ad-supported with limited functionality) or an inexpensive premium (Prime) version.

Nova gives me complete control of the RS6’s interface, from the apps and widgets that appear on the home screen, to the way notifications appear on the lock screen, and even how I group and arrange the apps on the player. Once installed, every single interface element is controlled from the Nova Settings app.

I won’t go into great detail here, other than to say your choices are almost limitless. From the shape, size and colour of icons (I use an excellent third-party icon pack called Lines to get that minimalist look) to the app drawer, launch bar, folders and other UI elements, it’s now all under your control. It also allows you to hide icons of apps that you don’t use, making for a far less cluttered UI.

One thing I will mention here is gestures. The RS6 already comes with the most useful of modern Android features, Tap to Wake (oddly called double click to wake in Settings), which as the name suggests allows you to double-tap the screen to wake it from sleep without having to press the power button. As with the R8, the RS6 doesn’t include the reverse feature, Tap to Sleep (or Lock), but fear not: a few clicks in Nova’s gestures options and it’s there.


File Manager

The RS6 is essentially an Android smart device, so why not use it like you would any other Wi-Fi-capable smart device? A basic file manager is included as standard (two actually), but you’ll want a more advanced app to take full advantage of the RS6’s capabilities. My rec here is Solid Explorer, which among other things, allows me to manage my entire music library wirelessly over my home network.

With Solid Explorer installed I never need to remove the SD card or attach the USB cable for file transfer. Everything I need to copy music and other files to or from my networked devices can be done wirelessly from the RS6. Solid Explorer gives me SMB access to my desktop Macs, workgroup access to Windows PCs, and remote access to NAS, FTP and Cloud storage, including Dropbox and other services. All of it can be done securely, and even encrypted, just as you would from any other computer.

With fast 5Ghz Wi-Fi support and a gigabit wireless mesh network at home, copying files to and from the RS6 is much faster than doing so the old USB 2.0 way, and almost as fast as connecting the RS6 directly with USB 3.1. I can also access and play music files remotely from Solid Explorer, but for that I use the remote playback capabilities of UAPP instead.


Music Player

Saving the best for last, no Android DAP should ever be without USB Audio Player Pro, or UAPP for short. UAPP helps me make the most of the RS6’s native audio hardware and networking features and turns it into a fully-fledged music playback and management system second-to-none. Since I also use UAPP on my smartphone, the experience is consistent and seamless, regardless of which device I use to listen to music, so much so that the first thing I did with the RS6 was disable HiBy Music in App settings (sorry HiBy).

The most important reason I use UAPP is its built-in support for the RS6’s audio hardware, bypassing the Android audio system and ensuring bitperfect output from headphones, line out and USB. It’s a very mature, very responsive and very stable application, with a clean, uncluttered, modern interface, including nifty features like background colours that match the cover art of the playing album, lock screen controls - including ambient display notifications on the RS6, and refined English-accurate menu and navigation structure.

It also features superb media management, including automatic updates to the main library when adding or removing music files, metadata editing, extensive album art support regardless of file type, and finely-tuned sorting capabilities, including Album Artist that many OEM music apps still seem to lack. And it’s fast, very fast. Everything from loading your library to gapless playback to scrolling and database updates is superbly optimized on the RS6.

UAPP integrates Tidal (with full 16x MQA support), Qobuz and YouTube Music, giving you access to your favourite streaming service with its native playback engine, though it doesn’t support offline downloads, and MQA support comes at an additional nominal fee. It also features advanced playback controls and effects, including optional ToneBoosters professional PEQ, Crossfeed and Morphit plugins, each as an optional add-on.

And lastly, it’s scalable, with built-in automatic support for external DACs that turns the RS6 into a high-end digital source for a desktop system. It also supports built-in DLNA and network music playback support, so you can access any of your local shares (including Plex libraries, in my case) directly from the UAPP interface.


Quick shout out to @Davy Wentzler, the creator of UAPP, for being highly responsive to my request to add native support for the RS6. Within 24 hours of speaking to him, he sent me a beta version of UAPP with RS6 support, which has now been added to the main retail version on Play Store.

Streamer

Most people choose Android DAPs for their streaming capabilities, and the RS6 is one of the very best in this regard. Not only does it support the highest level of hardware MQA decoding (16x) for Tidal users, it also supports bitperfect playback from hi-res streaming platforms like Qobuz, Apple Music and Amazon HD.

As a native Android player with built-in Play Store support, you have access to any of the major streaming apps out the box, including Tidal (which I personally use), Qobuz, Amazon HD, Spotify, Apple Music and YouTube Music, among others. If any of these apps support offline playback on Android, you’ll be able to use that feature with the RS6, and even choose where to store your offline files (internal storage or SD card).

One of the benefits of using a fairly modern Android version with a fast SoC is evident from how quickly the latest streaming apps load and run on the RS6, which to me feels even more responsive than the R8. Tidal is not the world’s fastest app, but the experience is as smooth and seamless as it is on my smartphone, which is to say excellent. Searches are instant, and scrolling through large playlists is lag-free.

Other useful apps

While I have other applications on the RS6 that can be used for music playback (including the native Tidal app and Plex), I generally don’t venture too far away from UAPP for most of my listening. Aside from UAPP, Plex is the only other app that requires the Google Play Store, which is why Play Store support is essential, for me, in an Android DAP. While Plex isn’t perfect (I mainly use it at home for TV and movie playback), it does have one invaluable music feature: remote support. Basically, this means that when using the Plex app on the RS6, I can access my entire 4TB+ music library wherever I am in the world.

Unfortunately, the Plex app doesn’t take advantage of HiBy’s DTA for bitperfect playback, downsampling all my hi-res FLACs and DSDs to 44.1 PCM, but that still beats not having access to my music library wherever I go. I do get full hi-res and DSD support, though, when I access my Plex library at home using UAPP’s built-in DLNA browser.

One last word about personalising the RS6: I can’t stress enough how big a difference a smooth, fast interfacemakes to the overall user experience. This was always a bottleneck with older, smaller Android DAPs, or DAPs with underpowered SoCs and older Android versions. That’s no longer the case with the RS6.


Sound Impressions

As I mentioned in my first impressions, and also in the R8 review, DAPs don’t have their own sound per se. They do, however, affect the sound of your IEMs or headphones by virtue of how much, or preferably how little, they emphasise different frequencies, but also by how resolving and technical they are.

This is important because it impacts the synergy between DAPs and different IEMs. A warm IEM paired with a ‘warm’ DAP (that either boosts midbass frequencies, relaxes treble frequencies, or both) could prove too much of a good thing. Conversely, the same DAP could be just the tonic to balance out a cooler or brighter-sounding IEM.

My personal preference is a transparent and technically capable DAP that doesn’t veer too far away from a neutral tonality across the FR and provides an even playing field for almost all IEMs. That way, I get to pick the ‘flavour’ of sound I want by picking IEMs with certain tonal characteristics, knowing that the DAP I plug them into won’t change them too much.

With that in mind, let’s discuss where the RS6 sits on the spectrum. Note that all impressions were made using the RS6 in high gain mode, with a Sennheiser IE 900 and Empire Ears Legend EVO plugged into the 4.4mm balanced output. I’ll discuss both these pairings throughout, and also compare the tonality and technical ability of the RS6 with the R8. The RS6 was ‘burned in’ for 150 hours prior to testing.

For a more comprehensive comparison between the RS6 and other DAPs, and notes on a wider variety of IEM pairings, keep an eye open for @twister6's review here.


Tonality

The RS6 is not a neutral DAP. There, I said it. While I haven’t heard the R6 2020 for myself, I did own the R6 Pro, which had some power to its tuning but was overall a balanced sounding DAP. While the RS6 is also relatively balanced, it does emphasise some frequencies more than others.

I’m hearing the RS6 to have a prominent bass lift, centred around the lower-midbass frequencies, and also a dominant upper midrange that sits a few notches above neutral. There’s also something happening in the treble region that’s adding more sparkle to certain high-pitched instruments like bells, chimes and higher-register strings than I hear with the R8. This gives the RS6 a warmer, slightly thicker sound than I’m used to with other DAPs, but with plenty of clarity through the midrange and treble. It’s not a veiling thickness, in other words.

The bass and midrange emphasis was initially more apparent out the box, before I had time to burn-in the player for a few days, but even after burn-in I could still hear the prominence in these regions, albeit far less abrasively. For example, basslines on tracks I know well, and which are evenly presented on the IE 900, were more apparent with the RS6, so Katie Melua’s Red Balloons had a weight and rhythm to its thick and lustrous bassline that was more dominant than usual. Similarly, Jillette Johnson’s edgy vocals on Bunny were a touch edgier here, the vocals themselves brought more forward in the mix.

To be clear, I’m not saying any of this in a negative way, because while the IE 900 is presenting with the same balanced sound I love it for, its energy is turned up a notch, and some vocals that are subtly recessed with other players are far less so with the RS6.

Conversely, switching IEMs to the mid-forward and bass-emphasised EVO tips the scales too far on some tracks. Anything with an aggressive midrange or an already-compressed cacophony of instruments, like Seven Lions’ Island (featuring Nevve) or Daft Punk’s Contact, both of which are borderline edgy on EVO already, are fatiguingly so with the RS6 (even though the latter was recorded far more proficiently than the former, it must be said).

This is where the synergy I spoke of earlier comes into play. The RS6 pairs up more agreeably – and in some instances preferably – with the IE 900, but less so with EVO. Of course, that’s just my perception, and you might find the extra energy with both IEMs more to your liking. The point I’m making is the RS6 is changing how I hear these IEMs compared to how I hear them with my reference DAP (the R8), but not always in a bad way. EVO still sounds great with most of my library on the RS6, as does the Legend X it replaced.

If I were to graph the RS6’s tonal ‘shape’ it would be a flat W, with the bass and midrange upticks slightly longer than the treble’s, but overall flatter than a prominent W-shaped IEM tonality. It’s a rich sound that pulls out enjoyable bass texture and kick-drum ‘kicks’ in tracks like James Gillespie’s What You Do, and adds more clarity and immediacy to many vocal performances.

Where the RS6 excels, to my ears, is vocal purity and realism. There’s a sweetness in the vocals of almost every track on Lana Del Rey’s masterpiece Norman screw*** Rockwell! that I haven’t heard with other DAPs, not even the R8, and as good as she sounds with both IE 900 and EVO on other sources, she’s absolutely sublime on the RS6.

This could well be the analogue nature of the R2R sound at play, and if so, is reason alone to pick the RS6 over other players in this price range, especially if you’re fan of sweet and sultry female vocals. Just be mindful of IEMs that present female vocals as forward bordering on shouty, because the RS6 won’t do those IEMs any favours, at least not without some judicious EQ (-3dB at 3kHz does the trick for me, thanks @MatW).

Overall I can describe the RS6’s tonality as warm but clear, full but not overly thick, and well extended at both ends. It’s not a light and airy sound, so if that’s what you’re after, best look elsewhere. But if it’s lushness, texture and bigger note weight you’re after, give the RS6 a listen.


Technicalities

With a midrange and low-end emphasis, the RS6 presents a natural but not overly-wide or spacious soundstage. I wouldn’t call it intimate, though it certainly can be with an intimate IEM, but it won’t close in your already-wide IEMs if that’s a concern. I also wouldn’t call it compressed – contrasty is a better word. There’s slightly less space between notes and instruments, but not in a thick and sludgy way, and not because of any added noise in the signal, but because the sound is pushed warmer and fuller than neutral.

Playing Agnes Noble’s The Curse, I notice how the opening instruments are set closer in from the extremities than they are with the R8, using both my IEMs. Agnes’s voice is also notably off centre and slightly to the left of the microphone with the R8, but is positioned more centrally with the RS6, at least relative to the smaller projected space.

The track itself plays with a dark background, warmed up slightly by the bass and the lushness of the vocals. The signature cellos in this track seem to purr and vibrate, adding a lovely texture and authentically analogue veneer to the presentation. Stage-wise, I’m sitting about five rows further back with the R8, while the RS6 brings me up close and personal to the performance.

I’m not hearing any hiss or fuzziness from the noise floor with any of my IEMs, even on high gain. Some consider noise an issue with HiBy DAPs in general, but I don’t hear it. That said, anyone using ultra-sensitive IEMs (like anything from Campfire Audio) would be best served with a lower gain level, at which point I can’t imagine noise ever becoming an issue.

The RS6 is very resolving, and at least on par for what I’d expect from a DAP at this price. The slight treble emphasis plays a part here, not in creating false detail through added brightness as some DAPs tend to do, but rather by adding focus and proximity to the shimmer and ‘ping’ of some high note instruments. The guitar plucks in Jethro Tull’s The Waking Edge are delicately sharp and very lifelike, while on other tracks, like Holly Throsby’s What Do You Say?, I’m hearing subtle guitar plucks far more clearly than I do on the more reserved and spacious R8.

This doesn’t mean the RS6 is necessarily more detailed than the R8, and in fact I’m hearing more subtle details in the R8’s vocals than I do with the RS6 despite the latter’s mid-forwardness, so it’s likely a combination of different emphasis on certain sounds, and also more overall contrast from the RS6, which tends to put greater emphasis on lower and higher-frequency sounds in particular.

Where the RS6 does fall short of its big brother flagship is in imaging and layering, and specifically how distinctly it places and separates elements on the stage. The subtle backing vocals in BEYRIES’ Alone, for instance, are easier to pick out with the R8 than they are with the RS6, and while the futuristic synth effects in Pink Floyd’s On The Run are well imaged on both players, they follow a larger and more precise left-to-right arc on the R8.

Overall I’d say the RS6 is excellent technically, though not quite at the same level as the flagship DAPs. It won’t diminish the technical ability of your IEMs, but it won’t enhance them either. The emphasis is more on tonality and overall musicality – if your definition follows mine – rather than pure technicalities. This is not an analytical sound, far from it, but then that’s exactly what I’d expect, and want, from an R2R-based player.


More on Sound…and Features

In the course of writing this review I’ve had a chance to engage with several users – and potential users – of the RS6, who asked a variety of not-quite-mainstream questions about sound quality and features. I’ll try and address a few of those in this section, before wrapping up.

DSD playback quality

As mentioned earlier in the review, the RS6 supports native DSD playback by using a separate DAC circuit specifically designed to decode DSD signals, something an R2R DAC can’t do without first converting from DSD to PCM. This means the playback chain for DSD is different to that of PCM audio, and so the question was rightly asked: how does it affect DSD playback quality?

That’s a difficult question to answer, but going back and forth between a native DSD (.dsf) version of Norah Jones’s Come Away With Me, and a bitperfect PCM conversion of the same track (.flac) does reveal subtle but audible differences. Whether or not you prefer the sound of the native DSD file or the converted flac file is very subjective, but what I’m hearing is slightly smoother, slightly warmer playback of the PCM file, compared to a cooler, more ‘precise’ rendition of the native DSD file.

Specifically, I’m hearing Norah’s voice to be sweeter with less grit in the PCM playback, and a touch edgier and more forward in the DSD version. The bass guitar strum at the bottom of the stage that accompanies the intro is warmer and fuller in the PCM version, and less pronounced in the DSD version, and the faint guitar plucks in the right channel are also more obvious in the DSD version while still present but less prominent in PCM.

You’d have to sample a variety of different DSD tracks and conversion formats to determine how these subtle – and I do stress they’re subtle – differences impact your perception and enjoyment of the music, but for all intents and purposes I enjoyed both, and without comparing side-by-side repeatedly probably wouldn’t have picked out most of the differences myself. There’s no doubt the differences are there, however.

RS6 as a DAC

Another point that came up in discussion was how the RS6 performs as a DAC for an external source, like a PC, and as a source for an external DAC.

The RS6 is one of the few DAPs with the ability to function as a wireless or wired DAC, via Bluetooth or USB respectively. As a Bluetooth DAC it can receive files in ‘hi-res’ Bluetooth formats like LDAC (990kbps) or HiBy’s own UAT format (1200kbps), making it essentially transparent as a DAC for redbook and some hi-res files, even though Bluetooth is inherently lossy. It can also transmit to Bluetooth headphones and IEMs using LDAC and UAT, which results in much-improved performance over standard SBC and AAC Bluetooth codecs, which I verified by casting LDAC Bluetooth from the RS6 to my Sony XM4 LDAC-capable TWS IEMs.

As a USB DAC the RS6 can not only decode files in any format from an external source, but also be set to receive input power while doing double duty as a DAC, meaning you don’t have to use up the battery while the RS6 is plugged into your PC. As a source, the RS6 can also output bitperfect audio to any external DAC, in all the formats it supports, including DSD.

This makes the RS6 extremely versatile, both as a standalone DAP, but also as an integral source or playback component in a computer system or larger hi-fi setup. The fact that it can also send and receive files wirelessly at the highest possible quality is just another arrow in its already well-stocked arsenal.

NOS vs OS

For most of this review, I’ve been referencing the RS6 from the viewpoint of its NOS sound quality. That’s because this is my review and I get to pick and choose how I write it. Jokes aside, this doesn’t hide the very obvious fact that the RS6 is not an exclusively NOS device, far from it. Indeed the most sophisticated hardware and software programming for DARWIN went into the creation of a 16X oversampling engine that, for many listeners, will provide a preferable sound profile to NOS.

I spent a fair amount of time testing different tracks while jumping between NOS and OS modes, and honestly the differences I picked up were subtle at best. Bass is ever so slightly richer and more saturated in NOS mode, and vocals ever so slightly crisper in OS, but going back and forth and switching tracks and musical styles and one could easily get confused between one and the other.

My experience with full-size desktop R2R DACs is that oversampling can have a far more dramatic effect on the music, bringing it closer to the precision and character of many Delta Sigma DACs in the process. The best DACs I used offer a gradual ramping up in OS levels, allowing you to gradually introduce the effect of oversampling, or bypass it altogether. I’m sure HiBy will develop these features further, and I expect to see more obvious differentiation between the two modes in future firmware revisions of the RS6 and even more so in future DARWIN designs.


Verdict and Closing Thoughts

When I decided to switch from desktop head-fi to IEMs, I was consciously aware that it meant giving up the type of sound I’d grown accustomed to over the years: the sound of a natural, earthy and authentic discrete NOS R2R DAC.

Over the years I’d come to learn and then appreciate the differences between Delta Sigma and R2R DACs in the same way that people differentiate between most things in the hobby. For me, the preference was squarely in the ‘measures poorly but sounds great’ world of R2R versus the ‘measures well but sounds flat’ world of Delta Sigma.

I’m exaggerating and generalising here, but the picture I’m hopefully painting is one where R2R – and specifically discrete NOS R2R – is synonymous with a rich, warm, comfortable sound that doesn’t exaggerate detail or technicalities yet still gives you an accurate and holistic representation of the music itself.

Until the RS6 was announced earlier this year, discrete R2R in DAP form was the preserve of the well-heeled. As far as I know, the P6 Pro from Luxury and Precision, at three times the price of the RS6, was the only currently selling discrete NOS R2R DAP available, with other R2R DAPs using chip-based R2R solutions instead. Cayin’s R01 discrete R2R board for the N6ii DAP, which preceded the RS6 and on which the R2R DAC in the RS6 is based, does not feature NOS support either.

Where the RS6 changes the game, so to speak, is not its R2R credentials as much as it is the combination of R2R and a modern Android platform. In the RS6 we have the world’s first, and fastest, open Android DAP with full streaming support, high-speed wireless and Bluetooth functionality, and fully discrete, NOS R2R audio hardware.

It could be the start of a trend, or just an anomaly in DAP design in response to the audio chip shortages currently befalling the industry (here’s hoping it’s the former). But nothing changes the fact that if you want the very latest in DAP features and performance along with a healthy dose of R2R, the RS6 is currently – and for the foreseeable future – your only option.

And honestly, it’s a great option. With the same tested, proven and stable software ecosystem as HiBy’s R6 2020 and R8 DAPs, the same design features, and the same powerful hardware, the only thing the RS6 really changes – and significantly so – is its sound profile. Gone is the reference sound of the R8; this is a more lively, punchy take on music delivery, with all the pros and cons. It sacrifices broad synergy for unapologetic energy, and trusts there are enough sliders and buttons for anyone to dial in their ‘perfect sound’ with their preferred IEMs.

Indeed the new DARWIN architecture is as exciting for its potential as it is for anything it tangibly delivers today with the RS6. Not only did HiBy opt for an entirely new sound system, using R2R in a radical departure from all its previous DAPs, but it built an entire software and hardware system around it, allowing for future expansion and configuration options with huge upside potential and very little downsides.

The RS6 is, in and of itself, a polished and capable performer already, even if it’s only version 1.0 of the new series. Technically it performs just short of flagship level, and yet has some of its own technical strengths over the flagships. Tonally it’s a departure from most other DAPs I’ve personally heard myself, with a warmer, fuller, more immediate sound that demands attention, especially so with strident or aggressive music and IEMs. But it also has a vocal sweetness and realism that belies the analogue nature of its NOS sensibilities.

Does enough to command a doubling in price over the virtually identical R6 2020? Personally, it’s no contest, given my affinity for R2R, and, now that I’ve spent some quality time with it, my affinity for its sound. Whether or not it ‘betters’ the R8 is a more difficult question to answer, and I admit the jury is still out as far as my personal preferences are concerned.

For me, a great DAP is the sum of all its parts – features, performance, stability, design, UX and sound quality. In my experience, few other DAPs comes close to the RS6’s combination of features, flexibility and sound quality, and no other DAP offers all of that plus R2R in one sweet and shiny copper package. Highly recommended.

The HiBy RS6 is available direct from Musicteck here: https://shop.musicteck.com/collections/hiby/products/hiby-rs6?variant=39597894795326

Introduction

Custom Art is the brainchild of Piotr Granicki, a hobbyist like so many of us that, in pursuit of his ideal sound, decided to make his own IEMs to get what he couldn’t find elsewhere. The result is a company now going 10-years strong, with an impressive and growing collection of IEMs that have found favour from as many performing artists as they have audiophile enthusiasts.

FIBAE 5 is the company’s first attempt at a tri-brid IEM, and in true Custom Art fashion, goes against the ‘norm’ with an unusual combination of dynamic driver bass, balanced armature midrange and planar treble. It also eschews the neutral reference-leaning sound of its higher-end IEMs, opting instead for a sound that’s fuller and warmer.

That said, FIBAE 5 is quite different from what I consider a ‘bass-first’ tuning, or even a V-shaped monitor (which it most certainly is not, to my ears). But before we get there, there’s plenty of other aspects of this fascinating IEM to consider, from the custom process and design, to the matter-of-fact accessories, and the relatively modest price.



Packaging, presentation and accessories

For a company that leads with artistry, FIBAE 5 arrived in a rather non-artistic, utilitarian case inside a nondescript cardboard box, though to be fair, there’s no real need for anything else. If corners need to be cut to hit a price point, I’d rather it be packaging than sound quality.

But I digress, everything you need is in the case, and there’s even a convenient foam block cutout to keep the IEMs from bumping into each other or getting scratched by the cable. In fact, the case is large enough to hold other small accessories in the mesh lid pocket, like the Bluetooth necklace cable that Custom Art sent me to try out alongside the stock 4.4mm cable.

Speaking of cables, I was supplied with what looks like an 8-wire silver-plated copper cable with a gold-plated 4.4mm connector and Custom Art branding. It’s soft, supple, not too thick, with no microphonics, and the metal hardware looks good and feels robust. I tried switching it out with a few different cables, some significantly more expensive, but I keep coming back to the stock cable as the most comfortable with the best sonic balance to my ears.



No doubt you can probably push performance higher with super fancy cables, but without getting too controversial, unless you’re buying a cable for better aesthetics or bling, I personally don’t see the sense in spending more than the value of the IEM on a cable when you can get equivalent performance for free with subtle EQ tweaks.

Custom Art also includes a small add-on tool in the box, designed to insert and remove a tiny filter that fits into the bass vent to drop the bass shelf by 3dB. I’m not sure why you’d want to neuter the bass, but I guess if your preference is for a more neutral, bright-leaning signature, the option is there.

Overall, this a very practical package of accessories, especially if you’re a touring artist who needs maximum protection for your gear and a bit of space to spare for select extras. And it’s not like you’re spending thousands of dollars for a fancy storage box that will likely get dumped in the cupboard anyway.



Design and fit

Even though it’s not a balanced armature-only IEM, FIBAE 5 still features Custom Art’s Flat Impedance Balanced Armature Earphone technology (it’s literally in the name). The company claims it to be “the world’s first revolutionary IEM design providing flat impedance and phase”, which practically means the sound won’t go haywire when switching between sources with different output impedance, as often happens during live performances, and more rarely at home.

I only really mention this here because it explains the genealogy of the name, since I’ve seen this type of tech before from the likes of 64 Audio and FiR and it’s not really new to me. What is new is the idea of using a combination of drivers that, on paper, you’d think would throw up all sort of coherence issues, but in practice, somehow don’t.

FIBAE 5 comprises three sets of drivers, five in total: a single 10mm dynamic driver for bass, dual balanced armatures for mids, a single planar for low-mid treble, and a single planar for ultra-highs. I assume it also features some sort of crossover, although I don’t have the details of its design or configuration, but I do know there’s a 3D printed waveguide somewhere in the mix, along with Pressure Optimizing Design (POD) that’s supposed to normalise the pressure in front of the dynamic driver for a smoother, wider soundfield.



Sensitivity is a modest 109dB at 2KHz with 0.1V input, and with a nominal 10-ohm impedance (give or take 2 ohms with the flat impedance tech doing its thing), FIBAE 5 is fairly easy to drive off any source without exhibiting hissing or background noise of any sort.

Tech aside, let’s get to the best part of the experience: creating custom art. In my opinion, if you’re buying a Custom Art IEM, you should really, really get a custom art IEM. Yes, I know not everyone wants customs, and they’re nigh impossible to sell, and FIBAE 5 is indeed available as a universal option. But come on guys, why would you pass on the chance to create your own masterpiece from Custom Art, of all places?

The whole process of selecting a design was refreshingly new for me, and I must say quite intimidating at first. I chose Custom Art’s ‘famous’ nebula, which is not part of their standard price options and in fact needs to be hand-painted onto each IEM, so that no two nebula designs are ever the same.

To complicate matters, I asked for my nebula to feature red motifs for the right earpiece and blue for the left, and to wrap the nebula artwork around the faceplate so it creates a seamless transition with the main body before fading away gradually into all-black nozzles. Lastly, I didn’t want the Custom Art logo, cool as it is, to interfere with the design, so asked for it to be placed somewhere less conspicuous.

Not only was Piotr most accommodating of my many tweaks and requests (including the logo move), the end result, as I’m sure you’ll agree, is simply spectacular.



The only (slight) disappointment was that the nebula appears quite dark and unassuming at first, and only really comes to life in direct light. But again, I digress. Fit-wise, FIBAE 5 is my first experience of a full-size custom IEM – my very first CIEM foray being Campfire Audio’s Supermoon in its shallower audiophile fit option, which I’ll incidentally be comparing to FIBAE 5 later in this review.

I must admit to being somewhat concerned about using a deep-fitting custom IEM, with my tendency to not really tolerate any foreign objects deep inside my ears for any length of time. But from first insert FIBAE 5 felt right at home in my ears. It was actually too much at home, and I found that the seal was not ideal, the sound lacking any meaningful bass impact without pressing the earpieces tighter to my ears.

Yet again Piotr has no issues with me returning the IEMs for a refit, and aside from the lengthy delays in getting them to and from Poland over the busy festive period, the fit and feel was appreciably better second time round.

I will say though, the fit isn’t anywhere near as tight as I expected it to be, and as such, while isolation is good, as is the seal, I get more isolation from universal IEMs with their silicone eartips (and noise canceling wireless IEMs, for that matter) than I do with the FIBAE 5 custom. Whether or not that’s how it’s supposed to be, I’m not sure, but if you expect total isolation (as in, not being able to hear any external sounds at all), you might be left wanting.



Sound impressions

I’ve been listening to FIBAE 5 for the better part of two months, although some of that time was spent sending the IEMs back for adjusting the custom fit. My impressions today are quite different to my initial, out the box impressions, and I can only put that down to the combination of a better seal and driver burn-in. I’ll mention of the changes I’ve experienced in the notes below.

All testing was done across a number of different sources, including HiBy’s RS8 and iBasso’s DX300 MAX using my full set of test tracks and casual listening with newly released music.

Tonality

Custom Art describes FIBAE 5’s sound as “energetic, visceral and powerful” and “energetic, bold and engaging”. This was maybe the case out the box, when the bass was a touch loose and treble was, for want of a better word, wild, but over the past few weeks the sound signature has settled down into something much more sedate, laid back, balanced and refined.

Tonally I hear FIBAE 5 to have a U-shaped sound, bass and treble sitting ever so slightly ahead of the midrange, but never distractingly so. The solid sub-bass foundation and smooth midbass transition gives notes a hint of warmth, and neither encroach on the open, clean and controlled midrange. Treble was peaky to start with, the planar drivers occasionally jumping their lane, but all that’s changed now, and treble plays a supportive rather than leading role along with the bass.



Bass is definitely more sub- than midbass focused. The sub-bass vibrations in Caroline Polachek’s Hey Big Eyes (1:13) give my skull a deep massage, the rumble sustained and well extended, with excellent control, clearly showing off FIBAE 5’s sub-bass emphasis. Feist’s Tout Doucement also exposes the deep, vibrant sub-bass notes from the upright bass that complement and contrast with the lighter parts of the arrangement, and never interfere with the vocal delivery, which is sweet and clear even when the bassline continues in the background.

Moving up the FR curve, it’s always good to round off a bass quality and quantity test with the kick drum, and they don’t come any more kicky than in the build-up to the Eagles live performance of Hotel California. What you want here is a deep thud that’s felt more than heard, and the punch of mid-bass notes lingering slightly to emphasise the kick sensation. FIBAE 5 captures the size of the drums with good texture and a decay that doesn’t rush or linger more than it should, and sounds very natural if not as bold and authoritative as I’ve heard it.

The same goes for electric bass drum intro in A Fine Frenzy’s Elements, which doesn’t quite hit as hard or deep as more bass-focused sets.

Overall, FIBAE 5’s bass response, while definitely muscular, is more honed than bulky. Bass plays a supportive role here, but unlike sets that use BA drivers as a bass foundation, the inclusion of a large dynamic driver gives the bass the realism, texture and timbre that, when called upon, will satisfy most bass lovers’ cravings. This is by no means a basshead tuning, however, so if you’re think FIBAE 5 can double as the bassy set in your collection, think again.



Midrange being the ‘star of the show’ is a cliché, but in the case of FIBAE 5, it’s true. That said, I don’t think it quite fits the profile of a mid-centric set, because the bass and treble make themselves known more often than not. That’s why, to my ears, FIBAE 5 is a refreshingly balanced set, but definitely one of the more accomplished I’ve heard when it comes to midrange fidelity.

The first thing I listen for in the midrange is female vocal purity, and what better way to do that than with the opening 30-second instrument-free intro to Fran’s How Did We. Maria Jacobson must have one of the purest, most emotive vocal deliveries I’ve heard in a while, and it helps that the band’s latest album, Leaving, records it almost perfectly. If there’s any sibilance, grain or haze in an IEM’s delivery, you’ll hear it. FIBAE 5’s delivery is literally pitch-perfect.

If well-recorded vocals are too easy, take it up a notch and try out a potentially pitchy recording. For all of Ethel Cain’s brilliance on her first full-length LP, Preacher’s Daughter, the weakest part of the album is Ethel’s vocal recording, even on epic tracks like Thoroughfare.

With an IEM that has too much upper midrange or lower treble emphasis, or that shows a lack of quality in these FRs, or that doesn’t have the low-end to balance out Ethel’s warmer low notes with her higher pitched trailing edges, this track will be a real challenge.

Thankfully FIBAE 5 doesn’t flinch, with as smooth a vocal delivery as I’ve heard with this track. It doesn’t quite have the reach and heft in the bass delivery to make the drums (3:14) reveal the cathedral-like stage of the recording and which provides such an important contrast to the vocals, but conversely it presents a very balanced, nuanced performance you can just close your eyes and sink into.

Switching to raspy male baritones, Neil Diamond’s warm and emotive vocal delivery form The Jazz Singer’s Hello Again illustrates FIBAE 5’s ability as a vocal all-rounder. I’d like to say I’ve heard this track with more grit and gravitas, but here the delivery is every bit as emotive if a bit less upfront, more laid back than thickly laid. The bass notes play a supportive role, so you’ll hear more of Neil’s lower midrange emphasis than some of the bassy chestiness in the recording.

Moving away from vocals, FIBAE 5’s midrange strength lies in its accurate instrument timbre. Playing Daft Punk’s Within is a great way to quickly check for piano timbre, one of the hardest instruments for an IEM to accurately reproduce. I’m no timbre expert, mind you, but I know when a piano, guitar or drum sound ‘right’, and the way FIBAE 5 presents the ‘live’ instruments in this hybrid electronic track is right on point.

Allen Touissant’s The Bright Mississippi reaffirms my impression of FIBAE 5’s timbral strenghs. Not that I’m big on instrumental jazz, but this is another track I often turn to for checking instrument timbre, and also how well the different bass, midrange and treble notes play across a live performance. It’s also a great track to test for instrument separation and imaging, for the same reason, and FIBAE 5 scores high on both counts.

Overall, I find FIBAE 5’s midrange to be very lifelike, with smoothness and warmth overlaid on clarity and nuance. It’s not the most resolving midrange delivery I’ve heard, but I’m not missing any details either, and very often I find hyper-resolving sets don’t lend themselves to a relaxing listen. In that regard FIBAE 5 is more forgiving of poorer recordings than some, and to me that’s a strength that shouldn’t be underestimated.



Treble is where opinions of the FIBAE 5 will probably be split, depending on how sensitive you are to treble vibrancy. Initially, I feared that the set would be hamstrung by the planar driver’s propensity for sharpness – out the box, some treble notes cut like a knife, and threw off the balance of the entire presentation.

I’m glad to say that, for me, this is no longer the case. Whether it’s the 100-plus hours of burn-in, or the slight adjustment to the fit of my customs, treble now mostly keeps to its lane, complementing and highlighting the details in tracks where necessary, but otherwise staying out the way.

Nils Lofgren’s Keith Don’t Go is a reference track if you want to find out how detailed, accurate, fast and clear an IEM’s treble delivery can be, or to test if you’re going to run into issues. It’ll also give you plenty of other information – male vocals, bass texture, resolution – but treble is what we’re here to hear.

When Nils plucks the high notes on his metal strings, they have every change of making you wince if not presented properly. Turn your attention to the sequence from 3:22 onward, and you should hear some extremely sharp and detailed high treble notes. There is a short sequence from 4:40 where FIBAE 5 comes really, really close to crossing the line, and teeters just over once or twice, so if there’s any weakness to its performance, this would be it.

This is an extreme example, but if your library comprises lots of steel guitars and high-pitched, bright arrangements, you might want to give the planar drivers at least 100 hours or more to settle like I did. Whether or not that will tame them enough for you, I can’t say.

Ilan Bluestone’s Will We Remain is another high-energy, treble-dominant track, but switches pace completely. FIBAE 5 is probably too laid back for this type of music, but it’s still a good way to test out the treble extremes, especially as it approaches the crescendo at the 3:15 mark. Treble is certainly lively here, but never crosses over to hot or harsh, and is nowhere near as sharp as Nils Lofgren’s guitar strings.

Orchestral strings are where you really want your treble timbre and detail to be on point, and FIBAE 5 absolutely gets it right with Max Richter’s Winter 1. There is just enough detail here to tell the difference between different string sections, and none ever come close to sounding strident. If anything, they’re quite mellow.

Overall, I’m very comfortable recommending FIBAE 5 for its treble performance, but caution that it did give me trouble in the past, and I’m not sure if what mitigated the issues on my set will happen with yours. I’m also about as far from a treblehead as you can get, and anything too bright or lively sends me reaching for different IEMs. FIBAE 5 is very well behaved in that regard, which is usually the best complement I can give this type of set.



Technical performance

There’s no denying that the higher the price, the more you’d expect from an IEM’s technical performance. To that end, FIBAE 5 doesn’t disappoint, but will most likely disappoint those who favour technicalities over tone. That’s because you’re not going to get envelope-pushing performance here, although for the asking price (which is still a very significant amount of money, to be sure) you’re not going to get short-changed either.

Ottmar Liebert & Luna Negra’s binaural recording of La Luna is a natural test for soundstage size, and reveals what I’ve been hearing consistently throughout my time with FIBAE 5. The stage is larger than average in terms of depth and height, but only moderately wide. It’s definitely not an intimate stage, and manages to spread out in all directions when the music, like this track, calls for it. But it’s not artificially expansive, and I probably wouldn’t call it holographic either. Sounds sit comfortably outside my head, but not so far away that they appear distant or diffused.

With its 50th anniversary coming up this week, Pink Floyd’s On The Run from Dark Side of the Moon is another great test for stage, but also resolution and imaging. It shows FIBAE 5 to be reasonably resolving, with imaging that won’t win any awards for pinpoint precision, but is more than acceptable at this price point.

Listen for the PA announcement that plays over the early part of this track. It fades quickly once the main effects start to play, so the IEMs aren’t squeezing the very last drops of information from what’s available in the file. Still, if you didn’t know what to listen for, you wouldn’t know anything was amiss either.

Pink Floyd’s Time follows on from On The Run, and reinforces what I picked up previously, in that resolution is very good but not outstanding, and imaging and separation are all at a very high standard too, but short of what you’d want for triple the price. For the record, this is another great treble and timbre test, and while some of the higher-pitched clock effects bordered on forward, none were so sharp that I needed to turn down the volume.



I specifically wanted to use Armin Van Buuren’s Intense for this review to make the point that FIBAE 5 is anything but what the title suggests. This is not a highly dynamic, in-your-face delivery; I can close my eyes and relax to music like this, which is probably not what the artist intended.

On the flipside, FIBAE 5 lets you revel in the beautiful tone of Miri Ben Ari’s electric violin, and while I did find myself head bobbing to Armin’s beat, I was drawn more to the composition and layering of the various effects in the track. If you’re someone wanting big notes with power and groove at full speed, this is not the IEM for you. If you prefer to focus on the melody, however, even in faster tracks like this one, FIBAE 5 is more likely your speed, as it is mine.

Overall, I really like what Piotr has achieved with the technical tuning of this set. You’re definitely a level or two up from mainstream, sub-$1,000 sets with stage size, depth, layering and separation, and there’s no shortage of resolving power either. It might not be the fastest and most dynamic sound at this level, but it’s not flat and uninspired, if that’s what you’re thinking.

Perhaps the best way to make the point is to compare and contrast FIBAE 5 with two other IEMs in the same ballpark price-wise to get a sense of where it sits technically, so I’ll do that next.



Select comparisons

HiBy Zeta ($1,299). HiBy’s 9-driver titanium body flagship is a relative newcomer to the IEM scene, with very little information actually out in the wild about it (shameless plug – THL review coming soon). The most obvious and immediate difference to FIBAE 5 is its warmer tonality; Zeta has a visceral, powerful midbass response that colours all the remaining frequencies with warmth, far more so than the more neutrally-tuned FIBAE 5 midbass.

It also has a relatively forward upper midrange that requires some EQ tuning, and treble that’s smooth but lively when it needs to be, compared to FIBAE 5 which is far more balanced in these areas. As such there’s more dynamism and contrast in Zeta’s sound, more realism and tonal accuracy in FIBAE’s.

Technically the two are very close. FIBAE’s stage is actually wider and deeper than Zeta’s, which is hampered by its added warmth. Resolution is on par, which is to say very good but not quite summit. Being a custom, FIBAE 5 obviously wins out in comfort, but Zeta is on the more comfortable size as far as universals go, especially with softer silicone tips. Its titanium shell is skin smooth, with no hard edges, and even though the metal earpieces are slightly heavier than FIBAE’s resin, they’re quite a bit smaller.

Overall, the two IEMs complement each other well, FIBAE being more balanced and accurate, Zeta warmer and more powerful. Zeta’s more elaborate packaging and higher quality accessories explains its larger pricetag, but both IEMs can be said to perform at a level that justifies their ticket price.

Campfire Audio Supermoon ($1,500). Planar IEM drivers are still new, and have some way to go before they can match their full-size counterparts. That said, Supermoon is the most complete example yet of a high-end planar driver in IEM form, showing off the good (and bad) of the driver’s characteristics.

Tonally, Supermoon is brighter and lighter than FIBAE, and lacks some of the iridescent warmth from the dynamic driver bass. This affects midrange and treble presentation too, both of which are on the thinner side compared to FIBAE’s fuller notes. Timbre accuracy is where FIBAE eclipses Supermoon, especially with vocals and live instruments.

Where Supermoon shines is its technical performance. It resolves as well as any IEM I’ve heard, regardless of price, and is faster with a better-defined stage than most summit-fi IEMs in my opinion. On the flipside, it lacks dynamic energy, and its tonal ‘flaws’ – especially a metallic sheen to some upper midrange/lower treble transients – takes some of the polish off its exemplary technicalities.

Overall, Supermoon offers a stark contrast to FIBAE 5’s lifelike, natural and balanced sound, which could be a good or bad thing depending on your preferences and need for a variety of different-sounding IEMs in a ‘collection’.



Closing thoughts

There’s something to be said for IEMs that represent more than just devices for music listening. Custom Art’s FIBAE 5 is the embodiment of this ideal, an IEM that, initially at least, is more about creation and craftsmanship than it is utility.

The care, dedication and skill that went into making my set of custom IEMs is an experience I’d wish on anyone. To my mind, it’s the main reason someone would seek out a Custom Art work of art. The only downside is the crazy variety of choices you’re faced with when deciding on the look of your personal set, something that admittedly gave this minimalist reviewer choice paralysis for a while.

When you start off on such a high note, everything that follows is sometimes a letdown. Thankfully, FIBAE 5 performs as well as it looks. While I had my teething issues with the sound, more specifically the planar treble liveliness, time and patience (and a quick visit back to Poland) ensured all was well once the treble settled.

Confoundingly though, I don’t hear FIBAE 5 as the energetic, dynamic IEM it’s ‘supposed’ to be, but rather a more relaxed, refined version of that ideal. It has the quintessential qualities of a dynamic driver bass foundation, and an expertly-tuned midrange that, I’m lead to believe, is Piotr Granicki’s trademark tuning. I can only assume the planar treble decision was an attempt at doing something oddly different with this IEM, to separate it from its siblings, perhaps?

Ultimately, it’s an experiment that seems to have worked in FIBAE 5’s favour, because the sum of this IEM is definitely greater than its parts. On the whole I hear no coherence issues, which speaks to the skill with which it’s been tuned. That said, it’s not the most technically-proficient performer I’ve heard, nor did I expect it to be, but at the same time, unless you’re willing to pay significantly more for a technical upgrade, it’s not going to let you down.

For me, FIBAE 5 is the consummate kilobuck all-rounder. I haven’t personally experienced a better all-round performer at this price. Considering the price includes your own set of personalised ear jewelry, I believe FIBAE 5 stands alone as the most enjoyable, comfortable, showoff-able and, importantly, affordable everyday listen I’ve come across in this hobby. Highly recommended.




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This review first appeared on The Headphone List.

Introduction

Aside from a few notable exceptions, it’s rare for a new IEM to come along and completely change the game. FiR Audio’s Xenon 6 (Xe6), flag bearer of the Washington-based company’s Frontier Series that debuted in late 2021/early 2022, is one such IEM.

The entire Frontier series can be said to be pushing the boundaries with FiR’s Kinetic Bass technology in particular, but Xe6 is radically different over and above all the new technology crammed inside its small, shiny shells. From the very first listen, it’s obvious that this is an IEM doing stuff on its own terms, unapologetically breaking conventions and defying what most people who pay the sort of highbrow money it commands generally look for.

All of this should, in theory, make Xe6 an outlier, a marginal success at best. But instead, Xe6 has smashed its way to the top of the popularity charts, beating off competition from other fancied high-end IEMs that cost more, are tuned more conventionally, or would normally be considered a ‘safe bet’, as much as that’s possible in this fiercely subjective hobby anyway.

Despite its success, Xe6 is still divisive. Those that love it absolutely love it, and those that don’t can’t get it out of their ears fast enough. Rarely have I met someone who’s had a casual listen and wasn’t moved one way or another. This, I think, is Xe6’s true strength – it’s an emotionally evocative IEM in the best, and sometimes worst, ways. One thing’s for sure, it’s not going to bore you, or simply be iterative over what you already own.

In this review I’m going to do things a little differently too. I’ll cover all the basics, but won’t repeat most of what I’ve already written. Instead, I want to get to the heart of why this IEM is different, and try to understand what that means for anyone who dares to go against the grain to experience music in fascinating new ways.



Frontier Series

Before we turn our focus to Xe6, let’s cover off some of the interesting new technologies that FiR engineered into the entire Frontier Series, which also includes the ‘entry-level’ Neon 4 (Ne4), and ‘mid-level’ Krypton 5 (Kr5).



Kinetic Bass. Big bass in IEMs has always been something of an oxymoron. After all, when we think of big bass, we think floor-standing speakers or subwoofers, massive dynamic driver cones moving large volumes of air as low-frequency waves that we ‘feel’ as much as we hear.

As you can imagine, this trick is a little more difficult to pull off with a driver smaller than your pinky nail. Not that IEMs can’t reproduce impressively ‘big’ bass – heck many IEMs do so better than headphones with drivers ten-times their size. But getting that much bass air to ‘move’ in such a small space is generally detrimental to just about every other frequency that comes after, often resulting in a thick, muddy sound that’s not particularly hi-fi.

Kinetic Bass literally flips the script on traditional dynamic driver designs. Using an outward-facing dynamic driver beneath an open-vented port above the IEM nozzle, low frequency sounds are transmitted directly into the inner-ear through the bone cartilage, in a process known as bone conduction. This allows the full spectrum of bass energy to pass through your ears in the same way that it does using full-size speakers, through air and bone conduction, which, in theory at least, makes the bass feel more immersive, extended and ‘real’.

Other IEMs use bone conduction technology to vibrate sound waves through the shell or ear tip, but no other IEM that I know of uses it specifically for the foundational bass frequencies through an open port, changing how we experience bass given the inherent physical limitations of IEM.



ATOM Venting. FiR’s Air Transferring Open Module is not a new technology for Frontier, but rather an existing technology adapted to better fit the new Frontier universal shells. ATOM is essentially a vent that releases air pressure trapped inside the ear canal, reducing fatigue and all but eliminating the reflex that causes your eardrums to protect themselves against prolonged exposure to loud sounds.

That’s not to say ATOM removes the failsafe built into your ears, but rather eliminates one of the main causes of listener fatigue, allowing you to listen for longer without the build-up of dangerous hearing-impacting pressure. It’s also not the same type of venting used in most ‘vented’ IEMs, which only serves to remove the pressure that builds up inside the IEM itself due to the air movement of the various drivers. That type of venting protects driver performance; ATOM protects your hearing.

Other benefits of ATOM include the perception of a larger soundstage due to improved airflow and reduced isolation. The flipside is exactly that – reduced isolation – so you’re more likely to hear environmental sounds using the most open ATOM modules. Of course, changing the level of isolation also changes the perception of certain frequencies, which means you can tweak the tuning of Frontier Series IEMs by swapping out different ATOM modules.



Open Acoustics. Most IEMs use drivers connected to sound tubes that direct sound through the nozzle into your ears. Frontier Series IEMs use a combination of three elements: open drivers, a sound reactor and a sound reflector.

All the drivers inside Frontier Series IEMs are open drivers, so they radiate sound directly outward into the IEM chamber. The sound waves pass through a sound reactor, which hones and refines it without resorting to dampening or filtering that would otherwise degrade the signal. There’s also a single high-frequency open driver that sits outside the main drivers (which are in the nozzle shaft), and fires at a sound reflector directed straight at the ear canal.

The end result of the different parts that make up the open acoustic system is a smoother, less brittle and highly dynamic sound, with excellent extension at both ends.



RIGID System. If there’s one aspect that’s often overlooked in the modern industrial design of many IEMs, it’s build quality. Thankfully this doesn’t apply to Frontier Series. Not only is the artistry, material quality and assembly of the Frontier IEMs exemplary, they also use a series of highly-resilient ‘RIGID’ parts to improve reliability.

These include what FiR claims to be the most durable 2-pin connector in the industry, rated for 1,000-plus connections, and a quadrant design that prevents the 2-pin socket from coming loose. Each Frontier Series nozzle is also fitted with a RIGID snap screen, an acoustically transparent steel mesh screen that prevents dirt and debris from reaching the IEM’s internals, and can snap on and off for easy replacement.

Two other RIGID technologies are used exclusively on the custom versions of Frontier IEMs, which we’ll hopefully get to review in a future article.

Taken together, these four technologies – some evolutionary, others revolutionary – make FiR’s Frontier Series IEMs some of the most advanced premium monitors you can buy, at least from a usability and longevity perspective. Each IEM goes beyond the core technologies, with varying driver configurations and tuning, to deliver a different sonic experience.

However, where Ne4 and Kr5 ‘toe the line’ in terms of the more conventional tonal and technical performance expected of high-end monitors, Xe6 tears up the script with a risky attempt at utterly unconventional. Does it work? Let’s find out.

Xenon 6

Packaging and presentation. FiR was clearly going for a ‘retro’ feel for the Frontier IEMs if Xe6’s spartan yellow/gold box with its basic back-to-the-60s industrial-style line illustrations is anything to go by. It’s different for sure, and I suppose you could call it modern-chic at a stretch.

Beneath the slip-cover, the box itself is a more traditional matte black with gold foiling lid-top, made of a thick-set cardboard. Removing the lid (which takes some dexterity as it’s very snug) reveals a cover letter with some poetic words about Frontier by FiR co-founder and CEO Bogdan Belonozkho, with warranty details and a short user guide on the reverse side.

The IEMs are nested in a plush foam cutout panel, pre-attached to the cable, which itself is rolled up beneath an iron-on Frontier Series badge that wouldn’t look amiss in a Tom Cruise movie.



Removing the top shelf also reveals the well-made leather storage case, inside of which you’ll find the spare tips (silicone and foam), a cleaning tool, the (micro) ATOM module holder, and the ATOM removal tool. The IEMs I received were shipped with foam tips pre-installed, which I immediately removed and replaced with my own silicone tips.

While it’s not the most lavish presentation I’ve seen at this price point, the whole look and feel is very satisfactory. The large leather storage case that also holds spare accessories is a nice touch, and the small design cues add to the feeling of a ‘themed’ IEM rather than just a generic IEM unboxing. Speaking of which, if you haven’t seen my unboxing video from the initial impressions overview, here it is again:


Accessories. In terms of accessories, the two most important are the stock Scorpion cable and the ATOM modules. I expect to see a good stock cable included with expensive IEMs, and the 8-wire 26AWG silver-plater copper Scorpion cable is just that. It feels well made, comes standard with a gold-plated 4.4mm Pentaconn connector, and is supple, light and kink-free. It’s also a very good match for Xe6 sonically, so there’s no need to search for an aftermarket option to maximize its performance.

The ATOM modules are without question one of the best features of the Frontier Series IEMs, but why FiR decided to shrink them to almost invisible dimensions (for the universal models – customs get the full-size modules) is anyone’s guess.

Changing the preinstalled ATOM modules is a pain in the tush, to put it mildly. Because they ‘screw in’ with a rubber gasket, you have to cajole them out of the IEMs, tilting the ATOM tool this way and that until the module ‘pops’ out. Do this very carefully, on a flat surface, preferably over some sort of container than can catch the module when it inevitably drops from the IEM (I used the carry case for this). Thankfully reinserting the modules is much easier than removing them, but again, do this slowly and carefully.

The included tips are nothing special, just a set of silicone and foam tips in three different sizes. I tried the small silicone tips briefly, which were too large for my ears, before finding a good aftermarket set that fit me better. Xe6 is quite responsive to tip swaps, and the sound can change quite dramatically based on the tips you choose. I really like Acoustune’s AET07 tips for their comfort and sound profile – especially in the midrange – but ultimately have settled on JVC’s Spiral Dots for their supreme comfort and easygoing sound.



Design and fit. From a technical perspective, Xe6 is the most advanced of the Frontiers. It’s the only tribrid IEM in the series, comprising a Kinetic Bass dynamic driver and a BA woofer for lows, a set of open BA drivers for mids, an open BA driver for highs, and a set of electrostats for ultra-highs (>12KHz).

Impendence is a fairly low 28 ohms, but there’s no flat impedance technology like there was in FiR’s previous IEMs (similar to the LiD technology used by 64 Audio and FIBAE technology used by CustomArt). This means source impedance may affect Xe6’s sound, something to keep in mind when auditioning sources.

The universal shells are extremely well made, with precision seams and expert surface plating. The gold finish is susceptible to microscratches, so if you’re someone who’s particular about keeping IEMs looking new, take extra care when handling or storing. The nozzles are medium length and quite thick, but not as thick as some other IEMs I’ve recently tried.

Fit is a very personal thing, but the shells seem to fit me fine. I use small size tips for my small size ear canals, and found several options that I could use to wear for hours without fatigue. Despite being made from metal, the earpieces are quite light, and won’t pop out your ears unprovoked. The earguides on the cable also provide comfortable support for the earpieces, so overall, it’s all good on the wearability front.

In summary, the packaging, presentation, accessories, design and fit of the Xe6 universals are top shelf, befitting their lofty price. Beauty is in the eye of the beholder, so whether or not you like the high-gloss gold bling with its sapphire glass and blue speckled inlay is not for me to say. What’s undeniable is how different these IEMs sound to just about anything else I’ve heard in the hobby, so that’s where our focus turns to next.



Sound Impressions

Tonality. Xe6 is first and foremost a warm, coloured, ‘fun’ IEM. Its tonality is characterised by a massive midbass and lower midrange shelf, an unusual tuning choice which pushes up the levels that more mainstream tunings (even ‘fun’ tunings) push down. There’s no linear bass with a midrange ‘cut’ to separate bass and midrange; instead, there’s a doubling down on big bass and mids.

Everything Xe6 does is based on some or other variation of its thick-but-clear personality. A vocal performance with a forward bassline will have you thinking that everything sounds too thick and warm, and yet when the singing begins and higher-frequency instruments start playing, there’s somehow no veil.

Despite its quantity, bass delivery is of exceptional quality too. Sub-bass focus suffers a bit because of the overabundant midbass, but there’s still some rumble when called for, and the midbass isn’t so loose that it spills all over the mids and highs. This is probably the result of Xe6’s unique combination of Kinetic Bass and a dedicated open balanced armature woofer, giving you ‘the best of both worlds’ when it comes to bass delivery mechanics.



The elevated bass and, more significantly, ‘overcooked’ lower mids would have been a bigger issue if the quality of the mids wasn’t so good. Instruments are full and weighty, yet still quite fast, with a pleasant, natural decay. Vocals, both male and female, are lush, warm and organic, but more importantly very, very smooth. There’s no harshness here, and the resolution of the open drivers is such that the smoothness doesn’t come at the cost of detail.

The same resolving smoothness extends to the treble, which is some of the best I’ve personally heard from an IEM. Keep in mind I like treble to take a small step back from the main performance, to give the overall presentation just enough sparkle and air, and then get out the way. Xe6 does this, but it also doesn’t roll off any high notes, and its use of an e-stat to add air up top without making everything sound ‘electrostatically ethereal’ is very clever indeed.

It’s hard for me to sum up Xe6’s tonality like I would most other IEMs. Is it a U or a W, for example? Depends on the track, sometimes it’s both. It can also be a V, with the mids taking a back seat, and it can be a reverse J, with everything subservient to the bass and lower mids with a touch of added air up top.

Tonally, Xe6 is like a chameleon, and although warm, thick and bassy are a given, they’re not always going to define what you actually hear once the music starts to play.



Technicalities. I think the reason Xe6 is so adaptable despite its exaggerated tonality is because of its technical performance. Resolution is top-shelf, and the stage, while not the widest I’ve heard, has a grandness of depth and height that few IEMs can match.

For a warm IEM, Xe6 can also deliver the goods, with the right music, with an ink-black background and impressive separation and layering of vocals and instruments. Sure, when the bass is let out the cage or the lower mids are pumped up in the recording, the finer nuances take a back seat, but I never feel like Xe6 has lost control at any point.

That could be because of all the IEMs I’ve heard, Xe6 has some of the better dynamic swings in the business. It can play tiny nuances in one instance and flip the switch to full-throttle explosive in the next movement.



This makes it an interesting choice for more conservative genres like large orchestral music, where big, brash and warm aren’t your go-to keywords, but in many ways it’s like listening to a performance at a live venue when you’ve had just enough to drink to make sitting through a classical ensemble seem almost…pleasant.

I jest of course, but I keep going back to the idea that with Xe6, you’re not hearing what you expect to. Still, because it’s so competent technically, the quality is good enough for even the more conservative among us to look past the tuning quirks, if indeed that’s how you hear them.

Technically, Xe6 can comfortably sit at the same table as some of the technical specialists of the IEM world, like Traillii, Fourté and Mentor, and while I don’t think it can replace any of those esteemed IEMs, I know which one I’d rather use most of the time.

Listening notes

Since this is a deep-dive review of Xe6, it won’t be complete without some detailed listening notes from my many sessions with it. Consider these stream of consciousness thoughts that I wrote down while listening, then tidied up to be legible enough to read and understand. Hopefully you’ll get some idea of what I’m hearing by reading the notes while listening along.

Note: all listening done with the HiBy RS8 as source, using low gain, and a maximum volume of 40/100. Xe6 is extremely easy to drive, so be careful when connecting it to more powerful sources.

Xe6 with…indie/pop

Lana Del Rey – Video Games. Xe6’s thickness is apparent from the first note. The electric piano intro sequence feels like it’s being played in a reverb room. And then, Lana starts singing and her sweet, emotive voice is as raw and beautiful as I know it to be, presented clearly and completely unveiled by the low notes. Xe6 does a great job with the first of the sub-bass ‘drops’ at 2:22, which can be felt as much as it’s heard, and all the while Lana’s hypnotic voice remains the centerpiece. Some of the lesser elements are pushed out to the extremities, but they’re still there. Xe6 can be quite intense, and this rather laidback track is a good example of how that intensity manifests in music with a strong, defined bassline.

The Shins – New Slang. In contrast to Lana’s bold intro, the tambourine and guitar intro to The Shin’s now-famous New Slang is rich and detailed without overpowering the stage, even though some of the lower-range guitar plucks have that characteristic Xe6 fullness to them. The male lead vocals are a little less forward, partially swallowed up by the lower midrange elevation would be my guess.

There’s something about the dynamic swings Xe6 is capable of that makes this type of head-bobbing melody even more so, and it’s all I can do to type while nodding like a bounce toy. This is a great track to demonstrate the quality of dynamic driver bass in a song without drums – it sets up the foundations against which all the sparklier notes and vocals contrast, resulting in an utterly engaging presentation as good as I’ve ever heard it.



Xe6 with…Americana

Brandi Carlile – The Story. The first thing I listen for in this track is the purity of Brandi’s opening vocals, and Xe6 doesn’t disappoint. There is a touch of bloom from the accompanying guitars, but it doesn’t make Brandi any less distinct. The second check on the list is kick drum impact, and Xe6 does a great job here too, the suckout of air from the drums clearly felt along with the texture of the drum hits.

When the instrumental melee begins mid-track, it is quite a bit thicker than I’m used to, and while every element is there, there seems to be quite a bit of warm air between the instruments. Going back to the simpler vocal passages is a relief from the thickness, but at the same time, as the song progresses, the warmth becomes more enveloping and comfortable. There are no hard edges here, but no smearing either. It’s the sonic equivalent of lump-free porridge of the tastiest kind.

Whitehorse – Dear Irony. Xe6 flexes some of its technical muscles with this track, throwing up an obviously wide and deep stage with the very first left channel guitar plucks in the intro, followed up by excellent separation of the female and male lead vocals, imaged precisely one behind the other. The vocals are contrasted against a thick bassline, which is very well done here, but does obscure some of the deeper sub-bass drums in the background.

What’s most important, though, is how emotionally the lyrics are delivered, and herein lies Xe6’s strength, its ability to subtly emote despite the sometimes overwhelmingly full sound. Vocals are absolutely clean – not a hint of grain or sibilance – and this is key to keeping the focus where it should be.



Xe6 with…modern classical/cinematic

John Barry – The Buffalo Hunt (from Dances with Wolves). This is one of my all-time favourite pieces of modern classical cinematic scores, and The Buffalo Hunt is one of its highlights. What’s most impressive is how well Xe6 resolves the wide dynamic range, strings, toms and horns. Spread across a vast stage, every subtle cue is easy to pick out, and there’s not one element that dominates the others.

Xe6’s thickness is also a non-issue, with instruments sounding ‘correct’, full of texture, with accurate timbre. There’s definitely some warmth infused into an otherwise colder production, but this elevates and improves it in my opinion.

Lisa Gerrard – Now We Are Free (from Gladiator). A masterpiece film topped by a masterpiece soundtrack by Hans Zimmer and his muse, Lisa Gerrard. The goosebumps appeared for me just as soon as Lisa started singing, which is more than I can say for many IEMs I’ve heard this incredibly emotional track with.

For me that’s not just because her voice sounds so pure, but because the power of the deep, dynamic bass notes, subtle string cues, deep stage and gentle, quivering backing track all combine to take me right back to the powerful, tragic and inspirational scene where I first heard this music. It’s transcendent as much as it is perfectly presented.



Xe6 with…singer-songwriter/folk

Eva Cassidy – Songbird. Is there a more iconic song than this to represent the genre, I wonder? The question for me before I pressed play was how much Xe6’s penchant for thick-set guitar plucks would interfere with Eva’s angelic voice and soft backing vocals. The answer, thankfully, is not at all. Yes, the guitars are prominent, but so is Xe6’s ability to forward-project female vocals.

Once again, not a hint of grain or sibilance, and when Eva hits the high notes, they’re so sweet that the tragedy of her passing can feel overwhelming. I really like how the accompanying shakers, and even the subtle strings in the deep background are clearly heard, but unlike some overtly technical IEMs that compartmentalize the sounds – impressive as that may be – they’re presented here as an even more impressively cohesive and musical whole.

Jim Croce – Time In A Bottle. What is it with me and tragic singer/songwriters? This is a simple recording that’s not so simple to reproduce well. It’s a thinner, colder recording that can sound harsh with some IEMs, but with Xe6 it’s nothing but smooth, detailed and completely captivating. Jim’s vocals take a small step back to the guitars in the left and right channels, but that’s a good thing as his voice can sound overly forward on this track. Xe6 makes it feel like I’m sitting in a room with Jim, guitars strumming to either side, and him just out of reach, as if foreshadowing what comes next so soon after this recording was made. Beautiful and sad, and Xe6 captures both so well.



Xe6 with…Classic Rock

Def Leppard – Love Bites. My personal pick from an album full of personal picks, Def Leppard’s Love Bites is lifted directly from the soundtrack of my youth. When I listened to it on endless repeat as a teenager, however, I wasn’t using such resolving and sophisticated gear. Xe6, with all its resolving power, takes me back to that time, because its smoothness, warmth and relaxed, rounded treble combine to tone down many of the harsher edges from this less-than-perfect, often too-bright recording.

What’s left is perfectly centered vocals, bouncy bass drums and guitars with crunch that I can enjoy without wincing. Cymbals and splashes are liquid-smooth, just as I like them, and the vocals have some added fullness to them too. Most importantly, the groove is absolutely on point. Brilliant stuff.

Bon Jovi – Runaway. As a teen I used to bounce between Def Leppard and Bon Jovi as my two anthemic ‘rock’ bands of the 80s and early 90s, and to this day they’re about as heavy as I like my music, with very few exceptions. There’s something about Xe6’s ability to fill out the rather meek bass drums of these older recordings too that takes me right back to when I used to blast these tracks on a 2-channel system with much bigger drivers.

I also like that there’s no harshness in the guitars, and Xe6 easily keeps up with the pace of the drumming and riffing in this classic track without any smearing or overlap. I can only think that those who prefer more grunge might find this presentation a bit too polite, but for me, it doesn’t get any better. In fact, I think Xe6’s thicker sound is probably better with these older recordings, before compression and the loudness wars took over the music industry.



Xe6 with…electronic/dance

Ilan Bluestone – Will We Remain. This is a newer track in my test library and a genre that is quickly becoming more than just a passing interest. I’ve never been into the dance/trance scene at all, but it’s music that I can lose myself in for hours – thankfully without the accompanying crush of gyrating, sweaty humans around me. Leaving real instruments behind makes it easier on the IEM for sure from a tonal perspective, but puts added emphasis on technical performance.

This is where Xe6 earns its stripes as a top-of-the-line performer. Every sonic nuance is important here, and the interplay between the different sounds on Xe6’s massive stage is captivating. This track in particular pushes Xe6 to the limit at both ends, with some very tight, taught bass notes followed by airy, spritely treble notes that need to be precisely imaged but not too forward or energetic. Xe6 pulls off this balance without breaking a sweat.

Armin van Buuren – Intense (featuring Miri Ben Ari). I keep going back to this track for its combination of modern classical and electronic elements, and also one of the few non-vocal electronic tracks I use to test gear. The beauty of Miri Ben Ari’s violin strings is always a highlight, and Xe6 absolutely nails the texture, timbre and realism here. The deep bass of the double-drop makes a perfect contrast with the strings, before the electronic elements and dance groove take over.

Xe6 manages to not only keep pace, but completely avoid any smearing. Sub-bass isn’t the deepest I’ve heard with this track, but the lower levels of midbass in the track help keep the performance clean and bloom-free. Once again, Xe6’s speed, dynamic contrast, imaging and resolution are on full display here, with Kinetic Bass taking care of the groove.



In summary. I’ve limited my notes to music I know well and the genres I mostly listen to. Of course, there’s so much more that I couldn’t include, and that goes for my own library, never mind the stuff I don’t ever listen to. Regardless of the music you listen to, one thing’s for sure: you can expect Xe6 to add colour, even though the way it does it isn’t always what you’d expect.

If you’re looking for a ‘reference’ tuning, this is not an IEM for you. But even if you’re looking for something fun and wild, Xe6 won’t always be that either. It really depends on how its tonality intersects with what you’re playing, and that’s what makes Xe6 such an exciting listen in many ways – you never quite know what you’re going to get.

Select comparisons

Sony IER-Z1R. Sony’s flagship is my ‘reference’ IEM, even though it’s far from what most consider reference sound. Xe6 is easily its equal, but in my opinion, not its rival.

I hear Xe6 and Z1R to have very different bass profiles, Z1R leading with a deep, liquid sub-bass and linear midbass, Xe6 the reverse, with a sub-bass supportive of an elevated midbass. Both have bass quality and texture that exceeds just about any other IEM I’ve heard, including Empire Ears’ bass champions. But, where Z1R’s bass is more even-keeled and balanced in the overall signature, Xe6 is always bass-first.

Midrange differs too. Xe6 has fuller mids, especially vocals, that are warmer than Z1R’s more neutral presentation. I don’t hear Z1R mids as recessed, though some do, and depending on the bass levels in the music, the same can be said of Xe6. Most of the time, however, both IEMs have some of the better mids I’ve heard, Xe6 being a touch more resolving, Z1R a touch more textured.

Z1R has more of a lower treble emphasis than Xe6, which doesn’t have any specific treble emphasis other than possibly a boost of air up top. Xe6 treble is smoother, silkier and more rounded, while Z1R is more incisive, detailed and sparkly. Both have superb treble quality, and I don’t really have a preference between them, enjoying both in equal measure.

Technically Xe6 is a touch more resolving, but Z1R casts a bigger, more cavernous stage, and its imaging and separation are at least on par. Both are very dynamic, but Xe6 even more so. Neither IEM loses too many points on technical performance, so the differences really come down to tuning and, for some, comfort and ergonomics.

Z1R is notoriously wonky in the ear for many people, while Xe6’s smaller, lighter universal shell should be a better fit for most ears. It’s not for mine, however, so an audition is really the best way to know which works best for you.



Unique Melody ‘Multiverse’ Mentor. I haven’t spent nearly as much time with Unique Melody’s co-flagship, but the time I did spend with it made it clear for me that it’s doesn’t have the same level of engagement for me as Xe6.

These two IEMs couldn’t be more different. Xe6 is bold and dynamic, with an inviting tonality that swings wildly between extremes. Mentor is more balanced, but also livelier and more energetic up top that gives it an oddly disjointed personality. Where Xe6 is rich, organic, and sometimes a little ‘loose’, Mentor is the definition of technical precision. Xe6 infuses music with a sense of tonal wonder; Mentor wows you with technical trickery.

For me, Mentor is not an IEM for bass lovers. For all its technical prowess, Mentor’s bass leaves me cold and unsatisfied. It’s the fly in the ointment of an otherwise impressive IEM, which becomes even more apparent when comparing it to the bass masterpiece that is Xe6. I know that’s not going to be a shared opinion by some, who take no issue with Mentor’s sub-bass rolloff and ‘balanced’ BA bass delivery as a whole. But for anyone who needs to feel the kick of a drum in a live performance, Mentor just isn’t the right tool for that job.

Nitpicking other differences between the two, Xe6 is by far the better-made IEM, with Mentor’s dullish exterior and structural ‘imperfections’ not quite up to the quality of Xe6’s pristine all-metal design.



Campfire Audio Supermoon. I’m only comparing Xe6 to Supermoon because I happen to have both on hand.

Supermoon is a custom IEM (though a universal version exists), so from a fit perspective it’s no contest in favour of Supermoon (though Xe6 is also available as a custom). Technically, Supermoon easily trades blows with Xe6 in all but dynamic contrast, which may or may not be as important to the music you listen to (and if it’s not, bonus points to Supermoon).

Where Xe6 overtakes Supermoon, in my opinion, is its tonality and timbre. Supermoon is colder and more ‘digital’ compared to Xe6’s warmer, more organic and natural tone. Supermoon also suffers from thinner mids, and the occasional metallic timbre in the upper-mid/treble region, whereas Xe6 is about as far away from metallic as you get.

None of this is to say that Xe6 is clearly the right choice for you over Supermoon. If you’re familiar with planar timbre and dynamics, you won’t have any issues adapting to Supermoon’s outstanding IEM-sized presentations of both. If you like your music superfast, resolving and clear, with world-class sub-bass to boot, Supermoon outdoes Xe6 there too.

Both IEMs are their own type of ‘crazy’ in many ways, and will appeal to those that don’t always want to play their music safe. In a way they’re kindred spirits, but definitely cut from very different cloths.

Closing thoughts

If Bogdan and his FiR Audio team wanted to make a bold statement about the state-of-play in the IEM market, Xe6 is about as bold as it gets. Here’s an IEM that doesn’t shy away from a smorgasbord of red flags: eye-watering cost, unapologetically boosted bass, unashamedly coloured sound…

And yet here we are. Xe6 is an enigma, an IEM that goes against the grain and yet garners far wider appeal than it has any right to. It ended 2022 as the number one IEM as voted for by members of the most popular thread on the world’s most popular portable audio forum. Having spent well over a month exploring my music library with this brilliant IEM, I can totally understand why.

Xe6 challenges how I listen to music, but it does so with an uncompromising degree of quality. From its meticulous build, the attention to detail in the design, and the cleverly creative technologies used to shape its sound, Xe6 delivers something completely different but also utterly engaging. It also compromises very little that’s important to the high-end audiophile in doing so.



Still, this is not an IEM for everyone. In fact, I wouldn’t recommend it as a blind buy. If you’re a one-IEM user, if your preferences lean more reference, if bright and light is your catchphrase, then Xe6 will more likely horrify than excite you. I’ve spoken to many who literally pulled Xe6 out their ears before the first song was done.

But, this type of reaction is nothing new for such a brave challenger to the status quo. I believe Xe6 will reward those who take the time to both find the parts of their library that work best with its presentation, and allow their brains to adjust to the way it presents those parts of their library that don’t.

There’s no question that, with some music, Xe6 will sound too thick, or too warm, or too relaxed up top. But, unlike many IEMs that bump the midbass and/or lower mids as much as Xe6 (are there any?), it doesn’t sound veiled, or bloated, or muddy. Sure, if you’ve just come off a session with a thin, bright IEM, your brain will need to re-calibrate. But once it does, you’ll hear how Xe6 lets all the detail through, creates a sense of space, and does it all without pulling back on its excesses.

This is an IEM that lets you have your cake and eat it too, even though it sometimes feels like it’s stuffing the cake into your ears and mouth and nose. It’s the most fun I’ve had with an IEM since I started in the hobby, and while I don’t think I can live on a diet of Xe6 alone, I can’t help but feel that a premium collection without it would be always be missing something special.




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This review first appeared on The Headphone List.

This is an abridged review. The full review can be found here.

The EarMen Sparrow does not do wireless. It’s also smaller than most other ‘proper’ dongles (unless you consider Apple’s or Samsung’s headphone adapters proper dongles). So what makes this tiny device so enticing to make you pick it over the many other options available at or around its $199 price point?


What you get

The Sparrow houses a new all-in-one flagship SoC from ESS, the SABRE ES9281PRO, the first combination DAC/amp chip to offer built-in hardware MQA decoding. Made from high-quality parts, including a gold-plated PCB, the DAC section supports all PCM formats up to 32/384kHz and DSD128 (including DoP 128 for Mac), and the amp delivers up to 4.0 vRMS of voltage from its 2.5mm balanced headphone output.

The face of the Sparrow features a LED indicator light that illuminates an EarMen logo in different colours based on its active mode: white when powered, green when receiving a USB audio signal, and magenta when decoding an MQA stream. It connects to your smartphone or laptop through a USB-C port on one end (EarMen supplies both a USB-C to C and USB-C to A cable in the box, but alas not a USB to Lightning cable for iPhones), and to wired headphones via single-ended 3.5mm and balanced 2.5mm ports on the other.


Sound quality

The story of the Sparrow, at least when it comes to sound quality and power, is a story of two outputs: single-ended and balanced.

Single-ended

Does the Sparrow, by virtue of its audio smarts, make your headphones sound better than a device that already has a built-in headphone jack?

The short answer is yes. Playing a well-recorded and multi-layered track like Brandi Carlile’s ‘The Story’ through my phone has always been a good experience. The LG’s superpower is its SABRE DAC, and I chose it specifically for this feature. But plugging the same IEMs into the Sparrow yields an even better one: Brandi’s vocals are notably more distinct, better separated from the melee of instruments around her, and the sense of space is better defined too.

Switching tracks (and genres), the classic ‘Hotel California’ by the Eagles is a staple demo track for most audiophiles because of how well it’s been recorded, and to hear it from the Sparrow takes an already pleasant experience on the phone (and even directly through the MacBook) to new heights. The version I like to use was recorded live and features on the Eagles’ Hell Freezes Over album, and from the very start of the track, as the noise of the crowd fades in and the guitars start to play, you’re treated to what I can only describe in layman’s terms as really excellent sound.


Balanced

If using the Sparrow single-ended is an improvement, using it balanced is a revelation. I can pick up the basic character of an audio chain from the opening chords of BEYRIES ‘Alone’, a simple vocal set against sparse instrumentation that on really good gear feels like Amélie Beyries is sitting right next you, singing in your ear. With the Sparrow connected balanced to a pair of 64 Audio IEMs, I could almost feel her holding my hand, a tear slowly parsing her cheek.

Where the quality gap was easily more obvious in the single-ended sessions, switching to balanced really blurred the lines between what I’d become accustomed to from my higher-end gear, and what I was hearing from the Sparrow. This was especially true with more complex music, like the busier passages in Daft Punk’s ‘Giorgio By Moroder’ and the collision effects in ‘Contact’ from the same, sublime Random Access Memories album, where the sound was more even, more controlled, less congested and better defined using the balanced output.

Often I’ve said I hear a wider stage and better separation of instruments with balanced headphones, no matter the source, which is not always obvious and always seems to be up for debate on the popular audio gear forums. Listening to the Sparrow, this point at least is not up for debate.


Other thoughts

By and large, the EarMen Sparrow has a very natural, neutral tuning that prioritises details but not at the expense of musicality. The sound can best be described as transparent, giving vocals and instruments just enough body so they don’t sound thin, without unnecessarily colouring the sound. It’s a fairly linear response, not too bright or too warm, with no unsightly peaks or troughs to worry the measurebators.

I’ve already established the Sparrow’s advantages when used balanced, so I’ll only add here that if you find the sound too intimate single-ended, it really opens up in all directions with a good balanced headphone. Not to mention, balanced is significantly more powerful, which brings me to one possible quibble: volume.

This is more a warning than a design flaw, but because the Sparrow doesn’t have its own volume control, I suggest you turn down the volume on your connected device before hitting play. Let’s just say I failed to do so first time, and have never in my life yanked earphones out of my ears so quickly. I can still hear the ringing…


Closing thoughts

That I’m finding a similar emotional connection to my music with a $200 dongle as I would be with a high-powered DAP is testament to how well this little bird can sing. While I won’t go as far as to say the Sparrow renders higher-end music players redundant, it definitely skews the value proposition downward, far further down than I anticipated was possible.

Is it the right device for you? That depends. Do you use wired headphones but don’t want or need a dedicated music player? Are you a Tidal subscriber with a playlist full of hi-res MQA tracks? Do you regularly use your laptop or tablet to play music? If you answered yes to any of these questions, the Sparrow is a shoe-in. In fact, if you are someone who prioritises sound quality above all else and want to take it with you wherever you go, the Sparrow should be near or at top of your list.

Effect Audio needs no introduction in the world of bespoke IEM cables. Founded by Sy (Zou Su Yang) in 2009, EA quickly became one of Singapore’s go-to companies for custom cables, and remains so to this day.

I’ve personally had limited experience of EA’s products to date, the Ares II – which I received as the stock cable with the Empire Ears Legend X – was technically my introduction to the brand, but Cleopatra is my first exposure to the type of cable that put Sy on the map as an innovator and groundbreaker.


The pitch

Cleopatra forms part of EA’s Heritage Series, second only to the company’s Hall of Fame ‘Summit-Fi’ cables. It’s an unmistakably well-made, precision-engineered, high-end cable, made with pure silver wire and a plethora of technologies EA considers its own. But unlike traditional silver cables, Cleo’s claim to fame is that the effect it has on sound is nothing like the bright, cool, shimmery cables that silver is often known for.

Instead, Cleopatra is a smooth seductress, infusing my IEMs with subtle warmth, but retaining the sparkle and open treble of a pure silver conductor. While I’ll get into specific tonal characteristics and pairings later, it’s fair to say that, like its namesake, Cleopatra is beautiful, soft, and oh so easy on the eye.


Like jewellery

If you’re anything like me, buying a high-end audio cable is as much about the look and feel as it is about the sound. With Cleo, however, you’re getting more than that. This becomes immediately apparent as soon as you hold the oversized box in your hands and feel the sheer weight of the packaging. The dark grey exterior features a slide-out section, with Cleopatra screen printed in clear white on the top half, and the Effect Audio logo embossed on the pull-out ‘drawer’ at the bottom.

Sliding out the bottom section reveals a velour-covered lid, below which sits one of the most elegant cases I’ve seen on any audio product, let alone an IEM cable. Like a fine piece of jewellery befitting a queen, Cleopatra is housed inside a solid, heavy-set box of carved stainless steel, hand-polished to a perfect mirror finish with a small, etched EA logo on the lid.

For a minute I completely forgot what I had in front me, and simply lost myself in the reflections of this orb-like object, as if it were some strange artefact gleaned from a visiting spaceship. Hesitating, I realised that touching any part of this glorious edifice would smear it with fingerprints, but, eventually, I just had to get on with it… (video of me polishing the mirror case for half an hour goes here)


Look, feel and features

Cleopatra takes the silver theme quite literally, with a see-through PVC jacket revealing the fine silver strands, and a custom polished steel Y-splitter that looks like a solid silver nugget. Even the chin slider is mirror-polished. The only part of the cable that looks ‘out of place’ is the 4.4mm Pentaconn-certified plug with its gold-plated finish and black carbon motif (which I suppose you can’t see when in use).

I ordered Cleo with EA’s new multi-connector system, ConX, which comes with matching polished steel housings (though you can select a glossy black option too). This being the Reserve Edition of ConX, EA included a small case with spare gold-plated 2-pin and mmcx screw-on plugs. ConX makes Cleo usable with all my IEMs, and is a highly recommended, inexpensive ($30) add-on to any new EA cable order (see my ConX impressions here).



Compared to the Ares II cable, which I’ve always considered quite stiff, wiry and tangle-prone, Cleopatra’s is finished in EA’s silky smooth UltraFlex PVC jacket that makes it both supple in hand and almost totally tangle-free. Try as I may, I’m yet to see an errant kink anywhere, and however I fold it, Cleo always returns to its svelte original form. Even the moulded ear guides are made of an ultrathin material that almost looks like part of the jacket itself, and disappears when wrapped around my ears.

Speaking of which, Cleo has to be one of the most comfortable cables I’ve had the pleasure of using. The combination of not-too-thick wire and an ultrathin, ultra-supple sheathing means once it’s in place, chances are you’ll soon forget you’re wearing a cable. The combination of the PVC jacket and cleverly designed Y-spit also makes Cleo the least microphonic cable I’ve used to date. No matter how much I rub the cable, against hand or fabric, almost zero friction noise makes it to my ears.

Not only is Cleopatra good-looking, like the feeling of soft, pampered skin, there’s some serious technology beneath the surface too. For starters, the cable itself is made up of four 26AWG gauge, extremely high-grade purity UP-OCC silver wires, Kevlar-reinforced, and arranged in a multi-strand formation based on the Golden Ratio principle. The 7-core wires are made with Litz materials, meaning each individual strand is enamel coated, giving it a larger surface area for signal conduction.

Whether or not you believe that arranging multiple strands of varying thickness wire in a naturally occurring pattern makes any difference whatsoever to how a cable conducts electric signals, you have to admit there’s a certain romanticism behind the idea. What’s not in question is the quality material that went into making this cable, which makes it as much a precious object as it does a utilitarian accessory. If you ask me, that’s exactly what you want if you’re spending the better part of $1000 on a cable.


Sound impressions

Before I start dissecting how I hear Cleopatra, I just want to clarify that I’m not actually hearing Cleopatra at all. It feels silly to even say it, but cables don’t make any sound. Duh, you say, but read enough cable reviews or engage in enough heated cable discussions online, and you’d almost swear they do! But alas, all cables do is move a signal from point A (your amp) to point B (your IEMs or headphones). Yes folks, it’s true, shocking as it may seem, it’s the IEMs you’re hearing, not the cable.

Silliness aside, I’m a firm believer that cables can and do affect how you hear the sound coming from your IEMs. Without getting into a scientific dissection of measurements and whatnot (cable deniers, please feel free to leave the room at this point, if you haven’t already), it stands to reason that if your IEMs sound warmer, cooler, thicker, duller, clearer or punchier, with the only changing variable being the cable, then the change in sound must be coming from…the cable, right? This is especially true if many different people in different parts of the world hear similar changes, right? Otherwise, the power of suggestion and hive-mind placebo must be a serious force to be reckoned with!


But I digress. This is how I hear the actual, audible changes Cleo makes with the IEMs I use:

Tonally, I hear Cleo to have a subtle warming effect on the sound. I believe that’s because it’s affecting the level of midbass, or midbass focus, relative to how the IEMs themselves present midbass. For example, the Sennheiser IE 900 has a more sub-bass-focused presentation, with a linear midbass that Cleo amplifies slightly and, in doing so, changes the balance of how I perceive the bass overall.

To my ears, sub-bass rumble is slightly reduced in favour of a smoother, more organic but less weighty bass profile, so the bass-heavy undertones in Katie Melua’s Red Balloons is not quite as solid and slightly more nimble when listening with Cleo (compared to the IE 900’s stock cable).

I’ve read some impressions that suggest Cleo elevates bass levels quite significantly but compared to the pure copper cables I’m using, the bass elevation is modest, at best, and tending more mid-than-sub-bass, as I described above. That means it’ll affect different IEMs in different ways, depending on the stock or aftermarket cables you’re already using with them.

Switching the Legend X’s Ares II for Cleo, for example, reduces the overall bass saturation, tightening up the bass notes and revealing some additional texture that may be missed with the stock cable in place. Switch out Cleo for a Cardas copper cable, however, and the impact and power of the Legend’s bass is pushed upward without the additional warmth of Cleo’s midbass saturation, tightening the sound further and giving it more slam while opening up the higher frequencies and revealing more detail in the midrange too.

While I don’t find cables affect the midrange frequencies directly, Cleo’s midbass lift adds a smoothness and musicality to the midrange compared to the brighter midrange voicing of the stock cables on both the IE 900 and Legend X, and is also smoother than how I perceive midrange of the new Legend EVO with the Cardas copper cable, albeit at the expense of some vocal detail. Lana Del Rey’s sultry vocals in Yosemite are more whisper soft with Cleo than they are crisp and ever so slightly coarse, but more nuanced, with the Cardas cable.


Where Cleo differs most from the generally warming copper cables I’ve used is in its effect on the treble, which is to say, it doesn’t necessarily brighten it up (as you’d expect of silver), but rather opens it up with the same smoothness it has lower down. As such I’m not hearing any added bite or sharpness to the music, but am hearing a touch more air and definition up top.

This is more apparent in IEMs that have a relaxed mid-to-upper treble emphasis, like Legend X and EVO, with less influence on the already sparkly IE 900, for example. Jethro Tull’s instrumental intro to The Waking Edgehas a touch more bite and ‘ping’ to it with the Legend X than it does with the stock Ares II, but it’s not through added harshness but rather more space for the instruments to breathe. How Cleo manages this juggling act while raising the temperature on the lows is something only Sy can tell us.

I’m not going to claim I hear any mind-bending technical improvements with my IEMs using Cleo, rather, that their technical abilities are highlighted (or downplayed) consistently with the subtle tonal shifts Cleo introduces. The more open treble does add to the sense of space in the soundscape, but that’s countered by the somewhat warmer midbass and smoother midrange. As such, I’d say Cleo isn’t going to magically expand the soundstage of your IEMs, but you might find it slightly easier to discern fine details in the music, especially in the upper midrange and treble.


Select pairings**

Sennheiser IE 900 vs stock cable. I hear a slight reduction in sub-bass weight and a slightly lifted midbass, which does change the overall bass presentation, integrating it more into the mix. Mids, especially lower mids, are rendered smoother, but the open treble does highlight the occasional treble peak that creeps into poorly or brightly recorded music with this IEM, more so than the stock cable. Overall I hear the IE 900 to have a smoother sound with Cleo, dialing down its inherent liveliness a notch or two.

Empire Ears Legend X vs stock cable. I hear a slight elevation of bass (possibly both sub- and midbass, but more evident in the midbass). This raises the overall perception of the bass, but doesn’t come at the cost of details, which are brought slightly forward by the more linear, extended treble response. The smoothness I heard with the IE 900 repeats here, and the Legend X’s already organic mids take on a more earthy tone as a result. This is a great pairing if you want to keep the Legend X’s legendary bass boost without smothering the rest of the frequency range and actually cleaning up the upper registers a touch more than stock.

Empire Ears EVO vs stock cable. Oddly I’m not hearing the same level of bass elevation using Cleo with EVO, and if anything the bass impact is either shifted slightly or reduced somewhat compared to the stock Genesis cable. This could be because the effect is skewed by the Weapon X bone conduction driver, but overall I’d say Cleo smoothens the EVO’s sound and takes a bit off its edginess but at the cost of some bass slam and impact and definition.

**All testing was done with a HiBy R8 in high-gain Turbo mode using the 4.4mm headphone output.


Closing thoughts

Cleopatra is a simply sublime silver cable that defies what most of us have come to associate with silver cables. Instead of pushing detail with a brighter, more forward treble tonality and/or a reduction and tightening of the bass frequencies, Cleo pleasantly surprises by adding a subtle warmth and deft smoothness without any loss of detail or clarity (with my IEMs anyway).

Depending on the IEM you pair it with, you can generally expect a healthy midbass bump and perhaps a touch of sub-bass elevation, which will present differently depending on how your IEMs present the bass in the first place. It also filters out some graininess in the midrange, possibly from the added warmth, but just as likely from the clever combination of rich, pure materials and ‘secret design sauce’ used in its construction.

I’ve resisted making too many subjective comments about the positives or negatives these changes have on my personal IEMs because, as we know, everyone hears these IEMs differently. What I will say without pause is that from a purely aesthetic, build quality and ergonomic perspective, Cleopatra takes pride of place among the very best luxury cables I’ve used.

It’s not too thick (though an Octa version is available for those that enjoy hosepipe cables), not too thin, with almost no microphonics. It’s also silky smooth and supple, making it virtually tangle-free, and takes full advantage of the high-purity silver in its core for a premium look and feel.

If you want a silver cable that behaves more like copper but without the occasional ‘copper veil’, or simply want a high-end cable for your high-end IEMs that won’t simultaneously break the bank with a daft multi-kilobuck pricetag or finger-thick aesthetics, I’d put Cleo at or near the top of your list.

Introduction

Campfire Audio is a name that needs no introduction, but here’s one anyway. In 2009, Ken Ball started a small boutique audio cable company in the green city of Portland, Oregon, called Audio Line Out, better known today as ALO Audio. From those humble beginnings the company evolved, and then split in two, with Ken’s sister company, Campfire Audio, introducing handcrafted in-ear monitors to the product line.

Fast-forward six years and 45 new or derivative designs, and Campfire is once again looking to disrupt a now mature IEM market. Supermoon, the company’s third custom IEM, is not only the world’s first custom planar magnetic IEM, but also the first high-end sealed planar monitor. Featuring a custom-developed 14mm planar driver and Campfire’s unique solid body sound chamber, the $1,500 Supermoon is already changing the price-performance equation of single driver IEMs at the highest echelons of the hobby.


Planar technology explained

You may be new to planar magnetic technology, especially in IEMs, but know that planar technology itself is not new. Planar magnetic designs have been around for years in full-size headphones, and even longer in speakers. What’s new here is the miniaturisation of the technology without sacrificing the inherent properties that make these drivers so effective in larger formats.

Unlike dynamic drivers which use a cone-shaped diaphragm, planar magnetic drivers use an ultrathin flat diaphragm and an array of magnets that push and pull the surface of the diaphragm to create sound waves. Compared to their headphone-size counterparts, there’s a limit to how large the diaphragm can be inside an IEM, and also how many magnets are used to energise the diaphragm.

Broadly speaking, planar drivers extend the frequency range in both directions, particularly bass, down to 20Hz and beyond 20,000kHz, while maintaining better linearity, a faster transient response, and lower distortion than even the most advanced dynamic drivers. The downside is that despite their exceptional extension, planar drivers tend to lack the dynamic contrast of the best dynamic drivers, even though they produce a ‘cleaner’ sound overall.

Supermoon specifically uses several techniques unique to Campfire Audio for refining its planar driver performance:
solid body design and 3D-printed interior. According to Campfire, solid body design ‘uses a single housing with specially designed ports…allowing [the] driver to be routed to the nozzle of the earphone’. The body-and-driver assembly is then ‘inserted into the housing much like an engine being lowered into a car’. This makes assembling the IEMs easier, and reduces sample variance by ensuring the design of each 3D printed earpiece is accurate and precise.

Supermoon also features a 3D printed interior, individually modelled to optimise acoustics relative to each user’s ear anatomy. In theory this lets Campfire design a unique acoustic chamber that helps shape the sound of each driver for a specific target, eliminating any variance in frequency response for consistent sound quality between units.


Packaging and accessories

I’d heard good things about Campfire Audio’s unboxing experience, and this being my first ever Campfire IEM, I wasn’t disappointed.

There are actually two parts to the ‘unboxing’. The first is an intricately folded cardboard sleeve with the Supermoon logo label on top, and a unique identifier label with the serial number and a ‘Nicely Done’ message, with my name, on the side. I really like how the personalisation of the custom IEM experience starts right from the very first impression.

Second, the actual hardboard box, complete with a more traditional hinged lid, contains the IEMs and accessories and sits inside the sleeve. Don’t throw the sleeve away, even though you won’t need it after opening.

Inside the box is one of the largest, nicest looking and feeling cases I’ve seen for an IEM. Campfire takes pride in their leather (outer) and wool (inner) cases, and the case that comes with Supermoon is no exception. Unzipping the case reveals two Campfire-branded drawstring mesh bags: a larger bag with the instruction leaflet, cleaning tool and Campfire logo button brooch; and a smaller bag holding the earpieces and attached stock cable.

The cable that came with my Supermoon is not the Smoky Litz cable advertised on Campfire’s website. Apparently there’s a shortage of 4.4mm cable terminations, and since I wanted a 4.4mm cable, Campfire opted to send me a different, slightly upgraded cable, the $199 4-wire Super Litz. This silver-plated copper cable is light, supple, and very ergonomic with molded, wire-free moulded ear guides. It exhibits zero microphonics in use, and is fitted with a decent looking Y-splitter and gold-plated plug. The MMCX connectors, on the other hand, are made with clear plastic, which cheapens the look slightly in my opinion, but does nothing to usability of course.

Overall the packaging and accessories are of a very high standard, and rightly so for a premium IEM that commands a relatively premium price.


Design, construction and fit

For a single driver IEM, Supermoon’s shells are large. If you were hoping for a tiny shell that almost disappears in your ears, this is not it. That said, the earpieces are quite beautiful to behold, with their deep dark-blue acrylic resin, hand polished and perfectly finished to the exact contours of your ears.

The driver assembly, electronics and cable connector are housed beneath a chromed stainless steel ‘faceplate’ abutting each earpiece, with the solid body acoustic chamber inside the shell itself.

Build quality is excellent; there are no surface irregularities, the faceplate is seamlessly melded into the resin body, and Campfire’s custom beryllium and copper MMCX connectors are renowned for their hardiness and reliability. The resin itself seems thick and robust, and although the nozzle is wide and appears unprotected, there’s a cloth-like mesh between nozzle and driver to keep earwax and other nasties away from the sensitive parts.

As for fit, this was the part I was most nervous about, Supermoon being my first custom. But the second I twisted the earpieces into place, I knew the fit was perfect. In fact, I thought something must be wrong, because there was literally no pressure anywhere, not where the shells rested against my outer ear, and not where the shorter ‘audiophile fit’ nozzles entered my ear canals.

It’s important to mention here, as I hinted above, that Campfire offers two different types of fit with their custom IEMs: audiophile and artist. Audiophile is a shallower fit, the nozzle protruding maybe half a centimetre into the canal. This is meant for home use, where you’re unlikely to be moving around too much, and don’t need the stronger isolation of a deeper nozzle.

Artist fit is a more traditional nozzle that goes past the first bend in the ear canal, giving you better isolation and a more secure fit at the cost of some intrusiveness and a potentially brighter sound, with the nozzle tip being relatively closer to the eardrum. Choosing the fit best for you is more a preference, and I’m assured by those that have tried both that there’s very little difference by way of sound and comfort with either.


Sound impressions (track notes are available in the full review)

Supermoon has an advertised sensitivity of 94dB, so it’s theoretically not the most sensitive IEM. Practically, though, it needs about the same amount of power as the Sony IER-Z1R (104dB sensitivity) to reach the same volume level, so while I’d say it appreciates moderately powerful amplification, it doesn’t need it to reach a moderately high volume.

I tested Supermoon over a one month period, using a broad range of test tracks and albums, many of which I’ve referenced below. Listening notes were made using HiBy’s RS6 and Sony’s WM1Z DAPs set at moderate volume. All tests were done using the ‘stock’ Silver Litz 4.4mm balanced cable.

Tonality

Before I’d seen any graphs of Supermoon’s frequency response, my sense was that it displayed a soft ‘W’ or moderate U-shaped tonal curve, depending on the source and the music. That’s to say, bass was emphasised a fair bit above neutral, from the very lowest sub-bass to upper bass, before gently dropping into the mids then rising up evenly from centre to upper mids and tapering off into a moderately emphasised and extended treble.

Bass

Let’s start here: if you enjoy a bass boosted IEM, you’ve come to the right place. Not only is Supermoon’s bass elevated, it’s done in a way that doesn’t beat the other frequencies into submission. I find bass emphasis leans towards the sub bass frequencies, where it extends almost infinitely low, but mid- and upper-bass are still very well represented. There’s zero midbass creep or bloom from what I’m hearing.

The sheer quality of Supermoon’s bass, however, is what sets it apart from many other excellent bass-focused monitors: it has a sublime combination of visceral punch, weight, electrostatic-like speed, and decay that surpasses some of the best dynamic driver bass. It doesn’t quite match the very best dynamic drivers for natural decay and timbre, but it has its own infallible character, easily out-resolving most dynamics I’ve heard, and making it unique among the current crop of top-tier IEMs.

In short, Supermoon’s bass takes me back to my full-size headphone days, where the mighty Audeze LCD-3 was my pride and joy. It renders every facet of bass almost perfectly, with restrained power and delicate control, punching tremendously hard and deep when it needs to, and rumbling gently if that’s all the track calls for. It doesn’t flavour every track with bass, but where the bass is the focus, that’s what you’ll hear and feel. Supermoon is a bass connoisseur’s delight, and its bass delivery is, for me, one of several stars in its show.


Midrange

I hear Supermoon’s midrange as fairly linear and supremely resolving, with a well-defined and textured lower midrange (male vocals sound natural and sufficiently chesty), and a moderate rise to a healthy but not overly forward upper midrange and pinna gain.

My personal midrange focus is vocals, and primarily female vocals, and I find the timbre of female vocals almost spot-on to my liking here. Male vocals are admittedly under-represented in my library, but those I regularly listen to sound about as lifelike as I’ve heard them.

Not once have I felt that Supermoon underplays or recesses either male or female vocals, but it can be temperamental when it comes to poor or compressed recordings. Whether that’s a result of Supermoon’s supreme resolution or unforgiving clarity in the upper midrange (and possibly lower-to-mid treble) I’m not sure. It’s not as rough as I hear it with some overly bright and mid-forward monitors, but it’s not as smooth or silky as Oriolus’s Traillii rendition, for example.

If I have to be critical of anything here, Supermoon doesn’t have the warmest, wettest or fullest midrange I’ve heard by any measure. It’s not a dry delivery as such, but it edges closer to thin, especially on older rock songs. If you are a stickler for instrument timbral accuracy, you might find Supermoon skews more synthetic for you, but if you’re a lover of emotive vocals and a sound that lets you hear every detail in a vocal recording, this is unquestionably Supermoon’s strength.

Treble

There’s a difference between generous treble and harsh treble, and Supermoon’s is definitely the former. I’m particularly sensitive to sibilance in vocals, spiky zing in a string solo, and harshness in a cymbal strike, and not once have I encountered any of the above with Supermoon.

Like bass, Supermoon’s treble is very well extended, at least right up to where my hearing trails off at around 12kHz to 14kHz. There’s bite to some recordings, and I warn those who think they can get away with playing overly bright poorly mastered recordings. Do that, and Supermoon will find you, and it will kill you.

This is not a consistently smooth treble, coming off as quite ethereal, and lending to some of the thinner notes the upper midrange can sometimes suffer from. But it also rewards great recordings with crisp, clean, and highly detailed highlights, with plenty of air where the track calls for it.

As someone who only really notices the treble when its harsh, grainy or corrosive, I’ve only ever paid attention to Supermoon’s treble for what it was doing right. This is treble filled to the brim with texture, and more detail than I sometimes care to hear. But, as with everything else, Supermoon is not forcing its treble detail on me, and I find myself listening to tracks on shuffle for hours on end without fatigue as a result.


Technicalities

As much as I enjoy Supermoon’s sometimes quirky but always engaging tonality, the wow factor has to be its technical ability. Supermoon’s technicalities are not just excellent, they’re supreme. It’s technical acuity is not one-dimensional either, and it excels in all but one measure, which I’ll get to later.

Stage size is wide and very deep by any standard. Supermoon can cast the tiniest notes about as far wide as I’ve heard them, maybe just shy of Traillii and 64 Audio’s Tia Fourte. Stage depth is where I feel Supermoon takes it up a notch. It has this ability to put different sounds closer or further away on the stage, giving it a great sense of instrument and vocal separation and an almost onion-like sense of layering.

Imaging and separation are both of the highest calibre, the latter even more so than the former, but resolution and clarity, as I’ve hinted before, are really what separates Supermoon from some of its highest profile competitors. This IEM is a sonic microscope, revealing even the smallest detail in a track without much fuss. It doesn’t always do this with the deftest touch, however, so the shortcomings of compression artefacts, cheap samples or sub-par recordings in poor quality tracks are often brutally exposed.

Where Supermoon doesn’t shine quite as brightly, if you’ll excuse the pun, is dynamic contrast. It suffers from what I believe to be a common planar magnetic trait in that the difference between the softest and loudest sounds in a track are not articulated quite as well as they are with some other driver types (notably dynamic drivers, but also balanced armatures).


Compared to…

Sennheiser IE 600 ($699). It’s probably fairer to pitch Supermoon against Sennheiser’s $1500 IE 900 flagship from a price point perspective, but since I currently only have its sibling with me, it’ll have to do. Aesthetically I really like the IE 600, which mirrors its flagship brother’s super small size, supreme build quality and comfort. If Supermoon wasn’t a CIEM, chances are IE 600 would be more comfortable, but nothing quite compares to a custom once you’ve tried it.

Tonally IE 600 ‘correct’, to the point where some might find it unengaging or boring, and that’s very much the case when I compare it to Supermoon. While I appreciate the safety in IE 600’s tuning, it doesn’t grab me quite like Supermoon’s. IE 600 has a touch more warmth and that single dynamic driver naturalness to it, but Supermoon isn’t far off.

Technically, though, the two couldn’t be further apart. Supermoon is significantly more resolving, to the point that you’ll be surprised just how much information you’re not hearing with IE 600 when switching between the two. Supermoon’s stage is also much larger in all dimensions, IE 600’s otherwise decent stage coming off as flat and intimate by comparison. Whereas I’d easily recommend IE 600 as an every day carry IEM, Supermoon is a more serious, refined, exciting and superior IEM all round.

Sony IER-Z1R ($1800). Sony’s flagship is getting a bit long in the tooth now, but still holds its own against the very best in the business. It also happens to be my all-time favourite IEM. From a fit perspective, Supermoon makes quick work of Z1R’s unconventional ergonomics. The Sony fits me just fine, but the same can’t be said for many who have tried and failed, often repeatedly. Build quality, however, goes to Sony, as few IEMs come close to rivalling its expert craftmanship and drop-dead good looks.

Tonally I hear Z1R to be warmer, lusher and also slightly edgier than Supermoon, especially in the lower treble. Its bass and treble are of such high quality, however, that even Supermoon’s pristine presentations struggles to match them. Sony’s big dynamic driver bass is fast, but not nearly as fast as Supermoon’s planar, although Z1R’s timbre is a shade more natural. I also prefer Sony’s vocal timbre, and although treble is more emphasised, it’s a dead heat from a tuning perspective.

Technically the Sony is excellent, one of the best when it comes to its sheer depth of stage and powerful dynamics, but Supermoon out-resolves it, has a wider stage, and also better imaging, layering and separation. What the Sony has over Supermoon in return is a unique presentation that puts vocals dead centre with instruments and effects all around you, sometimes even further beyond your head than Supermoon can manage. It’s also better suited to more dynamic music, and any track with a subwoofer is simply made for the Sony.

I find Supermoon and Z1R complementary. They’re both operating at a high technical level, and trade blows with each other tonally, but each brings its own version of events to every track. Z1R gives you that in-the-room feel and a wonderful sense of space, while Supermoon creates its own space and spreads the sonic elements all around you. With Z1R you’re fixed in front of the singer, far removed from the band. With Supermoon you’re on stage but free to walk around at will. Take your pick as to which you prefer, but in my opinion you can easily live with both and switch them up as your mood takes you.


Closing thoughts

Everything about Supermoon, for me, is ground-breaking. It’s my first CIEM, sure, but more than that it’s the first time I’ve heard planar technology shrunk down to IEM form. Not only that, it’s outperforming full-size planar headphones that pride themselves on driver size and magnet power, with a driver the size of a fingernail.

Overall, I find Supermoon’s combination of engaging, coherent tonality and world-class technical ability to be one of the high watermarks of IEM evolution. Sure it has some issues – a touch of glare, a treble niggle here or there, and a more genteel take on dynamic contrast. Like Ken says, it’s ‘far from perfect’. But show me a perfect IEM and I’ll show you one that doesn’t exist.

Are any of its issues showstoppers? That’s not for me to say on your behalf. I can only tell you that, from my perspective, the pros far outweigh the cons.

Supermoon is likely not for you if you prefer a neutral sound with less bass focus and a more even-keeled midrange and treble. It’s also not for you if you want a thick, luscious sound that romanticises everything you hear. And it’s not ideal if you mainly listen to compressed files, or low bitrate streaming, directly out your phone or computer. Supermoon is unforgiving in how it presents music, so be mindful of what you feed it.

All that said, if you’re the type of person wanting something completely different from the vast majority of high-end IEMs out there, Supermoon is just the tonic. It won’t wow you with textbook-perfect instrument timbre, but it’ll seduce you with how those instruments sound alive regardless.

A friend of mine recently called Supermoon a market disruptor, and I couldn’t agree more. I’ve heard none better at its price, and I’ve heard few better at twice and three times the cost. If you want the best value high-end IEM money can buy right now, this is it.