NuForce HEM6 Reference Class Hi-Res In-Ear Headphones with Triple Balanced Armature Drivers

Average User Rating:
  1. Cinder
    "Genie in a Bottle"
    Pros - Fantastic build quality, great detachable cables, very comfortable, seals quite well, excellent accessories, very clear, unique tuning
    Cons - Cables are semi-proprietary, clarity-focused tuning not for everyone, expensive
    Optoma NuForce HEM6 Review: Genie in a Bottle

    NuForce has been on my radar for quite a while now; their HEM series has had generally good reception from the audiophile community as well as the general consuming public. Multi-BA IEMs are the brand’s forte, and today I’ll be reviewing the HEM6, a triple-driver, three-way crossover IEM from the upper end of their lineup.

    You can find the HEM6 for sale on Amazon for $350 here.

    Disclaimer: This unit was provided to me free of charge for review purposes. I am not affiliated with Optoma beyond this review. These words reflect my true, unaltered, opinion about the product.

    Preference and Bias: Before reading a review, it is worth mentioning that there is no way for a reviewer to objectively pass judgment on the enjoy-ability of a product: such a thing is inherently subjective. Therefore, I find it necessary for you to read and understand what I take a natural liking to and how that might affect my rating of a product.

    My ideal sound signature would be an extended sub-bass with a leveled, but textured, mid-bass. The mids should be slightly less pronounced than the treble, but still ahead of the bass. I prefer a more bright upper range.

    Source: The HEM6 was powered like so:

    HTC U11 -> USB-C adapter -> earphones (not recommended)


    Hidizs AP100 3.5mm out -> FiiO A5 3.5mm out -> earphones


    HiFiMAN SuperMini -> earphones (recommended)


    PC optical out -> HiFiMe SPDIF 9018 Sabre DAC 3.5mm out -> earphones

    All music was served as MP3 @320Kbps or as FLAC.

    The HEM6 plays more nicely with warm sources than it does cold ones and scales well up the source tree.

    Sound Signature
    Initial Impressions:

    Coming from daily use on the W-shaped Kinera H3, the HEM6 sounded horrible on first listen. The upper register was sharp and grainy, making even tame songs sound harsh and uninviting. However, after about three hours of listening, much of that faded away. My ears adjusted to the sound signature making the experience much more bearable, and dare I say, pleasant?

    The HEM6 strives for a “Hi-Fi” tuning meaning it has a robust, but subtle, mid bass, a well matched sub bass, leveled mids and a slightly emphasized treble.

    Treble: Songs used: In One Ear, Midnight City, Outlands, Satisfy

    The first thing I think of when asked about the treble of the HEM6 is just how far it extends. You truly get a sense that you’re hearing the entire spectrum of the upper register.

    There are no hints of sibilance when using the correct sources (i.e, high quality ones). Unfortunately cheap sources do have a habit of making the HEM6 misbehave. The outputs on my SoundBlaster E3 and HTC USB-C adapter are some such offenders.

    The HEM6 does a good job portraying a very natural amount of air and lends well-recorded albums a great sense of scale and separation.

    Mids: Songs used: Flagpole Sitta, Jacked Up, I Am The Highway, Dreams

    The HEM6 is tailored to provide the listener with a bright an energetic midrange, if not one that is particularly accurate for “reference” uses. You’ll find that the upper-mids are quite a bit more prominent than the still-intelligible lower-mids, and that the vocal range (from roughly 2KHz-5KHz) is similarly emphasized. Instrumental separation is therefore quite good and above average, even for this price point.

    Guitars sound great, both of the electric and acoustic variety. On properly-mastered songs you can hear everything; the sliding and plucking of the pick against the strings, and even sometimes the slamming of a hand down to silence the guitar. Drums are similarly impressive, as are pianos.

    The HEM6 does not seem to favor male, nor female, vocals in any particular way, though I’d say they could both use more weight.

    Bass: Songs used: Moth, Gold Dust, In For The Kill (Skream Remix), War Pigs (Celldweller Remix)

    The HEM6 is apologetically not a mainstream IEM. Instead of the typical V-shaped emphasis on the lower register that many more consumer-esque IEMs feature, the HEM6 makes use of bass only when strictly necessary. This makes its application of punch and rumble subtle, but still noticeable and well-shaped.

    While the HEM6 performs fine on most genres, I’d generally not recommend it for bass-intensive ones, specifically electronic (and its various, and apparently infinite, sub-genres). Yes, it does rumble, and yes the bass can be punchy, but it’s not the overall experience that I look for from that portion of my music library.

    That being said, I do think there is definitely an argument to be made justifying the HEM6 as a clarity-focused jack of all trades when it comes to bass, though, again, that is all personal preference.

    Packaging / Unboxing



    Please be aware that the packaging came damaged as the box was mangled by Fedex. As such, I had to unbox it off-camera to make sure nothing was damaged. I repackaged it as best as I could for this photoshoot, but some things may be slightly out of place when compared to a brand-new and sealed HEM6.

    Construction Quality


    Other manufacturers could learn a thing or two from the HEM6’s build quality. There are no uneven seams, there’s no unsightly panel gaps (ahem, RHA), and there are no blemishes on the finely-finished driver-housings. Furthermore, even the thin nozzles feel very sturdy. Both are made from a matte plastic.

    Optoma also found a great spot for the vent that won’t get blocked by my oddly-shaped ears, an issue I have quite often when the vent is placed on the inside of my IEMs.

    The HEM6 uses a semi-proprietary implementation of 2-pin detachable cables, much in the same way that Trinity Audio does. I wasn’t a big fan of it with them, and I’m not a big fan of it with the HEM line-up. The difference, however, is that the HEM6 actually implements this kind of design quite well and provides a lot more stability to the 2-pin connection, just at the expense of easily finding third-party cables. So while I would have proffered to be able to safely use any third-party cable with the HEM6, I can understand why Optoma went with this type of cable.



    Speaking of cables, Optoma bundled the HEM6 with two quite good ones. One is a braided TRS-terminated cable with simple heat-shrink Y-splitters and chin-sliders. I quite like this cable. It doesn’t hold a lot of body and is quite sturdy. Microphonics are minimal and it’s comfortable on the ear.



    The other cable is made from a standard rubber and holds a good amount of body. It, however, has inline controls on it, as well as a mic. The controls work with both Android and iOS feature the standard pause/play/skip functionality.

    Both cables are quite nice and appear to be durable. Each features a form of memory-wire ear-guides which work reasonably well.


    The HEM6 is amazingly comfortable. I can wear it throughout my entire 10-hour work day with no issues at all. This is attributed to its light-weight build, over-the-ear design, and very small nozzle diameter.


    Optoma went ham on the accessories for the HEM6 and it is absolutely wonderful. Inside the box you will find:

    • 2x pairs of Comply eartips
    • 2x detachable cables
    • 6x pairs of silicone eartips
    • 1x shirt clips
    • 1x 1/4in to 3.5mm jack adapter
    • 1x IEM cleaner
    • 1x semi-hard carrying
    • 1x water-resistant hard carrying case


    The semi-hard carrying case is a good size, and easily fits the IEM and a cable. You could probably also squeeze in some extra eartips or the other cable as well.



    The hard carrying case is also really good. Its water resistant and large enough to fit literally everything that comes with the HEM6 with ease. I can quite easily fit a DAP and the semi-hard case in it with no problems.

    The HEM6 gives buyers a true taste of highly-resolving sound, excellent construction, good tuning, and great accessories. As a package it has almost no flaws, except its price. An argument can be made for it though: yes, you can find IEMs that sound nearly as good for a little less money, but you would be hard pressed to find anything that for less money that doesn’t make large sacrifices to the build quality or accessories. So I think one would be justified in saying that the HEM6 is a great offering from Optoma, even at the $350 price point. If you are in the market for highly-ergonomic and resolving IEMs, definitely check out the HEM6!

    Thanks For Reading!
  2. Hi-Fi EDU
    ""Dark Relaxation" - NuForce HEM6 IEM Review"
    Pros - Strong, Deep Bass/ Accurate Imaging/ Nice Stage Depth/ Great Clarity & Detail/ Non-fatiguing/ Excellent Isolation, Comfort and Accessories Package
    Cons - Slightly Muted Upper mids and treble ***Not inherently but more so comparatively*** / Stage Could be Wider/ Lacks some "Air and Sparkle" ***
    "Massdrop Blue Box - NuForce HEM IEMs" special drop pricing = $169.99*; Actual MSRP = $399.00​
    (I joined the drop on Massdrop and received the HEM6; LINK. You can find these and the other HEMs at your typical online retailers. Obviously, the drop has long since ended).​
    Introduction, Please!
    I'll preface my personal review by saying that I'm way more of a full-size headphone guy than an IEM guy. I used to own the Shure SE215 IEMs, which I sold as soon as I decided to commit to the drop. My current full-size headphone stable includes the closed Fostex x Massdrop TH-X00 and the open Hifiman HE-400i, both driven by the Grace Design x Massdrop m9XX DAC/Amp (mouthfuls...I know). From the healthy stock tip selection, I chose the Comply T-100 medium tips** and picked the braided cable for my use with the HEM6. I listen to all genre of music except death/hardcore metal.
    To my ears, the HEM6 have a darkish sound signature. Although I believe in mechanical and brain burn-in to an extent, I noticed no change in tonal signature in 35+ hours of burn-in. I think my initial impression of these as sounding "veiled/murky" was an attempt at describing the dark signature, but "murky" was not the appropriate term (all these dang audiophile terms!!! [​IMG] ). They do however sound kind of congested from my iPad2/iPod Nano 4G, while sounding clearer from my m9XX. I elected to use the m9XX when forming my impressions below. Although the HEM6 have a high sensitivity and get loud easily on my i-devices, I may need to look for a better portable source. Not that anyone needs to break the bank for that in this case.
    Get to it, how 'bout that Sound?
    In presentation, the HEM6 produces an impactful, well-extended bass that takes center stage when called upon. This is my first experience with balanced armature drivers and BA bass production (and also with NuForce products). Coming from my beloved X00's bass, I can say that I really enjoy the HEM6 low-end. I think it has solid mid-bass thump and detail despite what I've heard about BA drivers. Bass-driven genres work well with these. For me it definitely passes the Wiz Khalifa - On My Level bass test (LINK). The HEM6's bass quantity is about similar to my memory of the SE215's but much improved quality-wise with no bleed into the mids. In tone, the low-end is not as quick/taut as that of the 400i but is also not as smooth as that of the X00; its bass tone sits somewhere in-between.
    A clear but slightly less forward midrange follows suit, with a fairly muted treble bringing up the rear. The latter is one of the very few issues I take with the HEM6, as there is less air around vocals and less "sparkle" than I prefer. For example cymbals can sound dull, trumpets slightly restrained, and acoustic guitar plucks less edgy. No Regresar from the Bleach OST is a prime example of the latter (LINK). In comparison, my X00 reproduces the bite of each guitar pluck with more excitement than the HEM6. That same song also has more ambiance on the X00. This somewhat muted nature of the HEM6's upper mids/treble does minimize any sibilance and harshness problems; that in particular is a plus to me. However, overall air and texture of vocals is better presented by my X00 (i.e. less veiled), with the open 400i being even better. Ironically, I gained a greater appreciation of the X00's vocal and treble presentation from this experience. For me, the HEM6 would definitely benefit from a touch more upper mid (likely the 1-4khz presence region) and treble energy. ***{Please also take a look at EDITS at end of review}***
    Imaging, Soundstage, Resolution (Action!)
    All that said, the HEM6 images quite accurately (its best sonic trait along with the bass) within a soundstage that is surprisingly deeper than it is wide; there's good layering and instrument separation. So much so, that I actually had the fleeting thought that I could comfortably game with these...the seed has been planted (Update: they're definitely manageable for gaming). I almost hesitate to admit this to myself but these image better than my X00 and as proficiently as my 400i, though the two full-size headphones do benefit from having greater width to their respective stages. To my ears, the HEM6 could use a bit more stage width; again, more treble presence might have helped here. The HEM6 is also very capable of picking up low-level information, despite the dark signature.
    Package & Usage (Kinda like PB&J...kinda)
    Accessories, build and isolation are top-notch. The level of isolation with the Comply tips is honestly kind of scary. I now have to be even more careful when out and about. The sweet braided cable and shell finish are both black, understated and soft to the touch; both also appear durable. Oddly, the shell finish can pick up some fingerprints but it doesn't bother me, personally. The welcome carrying pouch has a hard, canvas exterior and just enough space to store the IEMs. I've always dealt with some ear canal irritation due to IEMs but so far, I've surprisingly experienced zero comfort issues with these for whatever reason. Maybe the HEM6 insert more ergonomically and stably than my departed SE215, which would sometimes migrate out of my ear canal on bass thumps? Maybe these Comply tips are simply better than the foam tips that my SE215 used? Maybe the greater flexibility of the braided cable around my ear allows these to sit more firmly in ear? Maybe it's a combination of all the above...I'm not sure, but I'm liking the comfort a lot!  Well done there NuForce/Optoma.
    Unsurprisingly, the HEM6 outperform my SE215 in every other conceivable way (again, from memory). The two sound more similar than dissimilar in tonal signature, but the HEM6 offers much better clarity, resolution, imaging and comfort.
    Get to the Conclusion, s'il vous plait...
    On my "audiophile" journey, I haven't had much exposure to this type of dark signature. As a result, these sound like nothing I've ever owned. The only other sound profile that these remind me of is the Audeze house sound, which I was able to experience for the first time at a recent meet (LCD 3 & X). That was one of my least favorite tonal signatures from the meet, really for the aforementioned reasons. However, the brevity and bustling nature of a meet are the reasons why you have to be careful about passing premature judgment on a pair of headphones/sound signature. The impressive technical proficiency of the HEM6 is somehow enough to keep me from disliking its darkish tone, and actually makes these quite a relaxing listen for me. As a result, I also find the HEM6 rather forgiving of source material. I get the feeling that if these had slightly more upper mid/treble energy, they would sound better balanced to my ears and very similar to others' description of the HEM8. Hmm... [​IMG] Not being a big IEM guy, the HEM6 are possibly my end game IEM and I am fairly happy to have received them from my gamble on the Massdrop Blue Box.
    **Addendum on tips - At the end of my assessment with the Comply M tips I figured, why not do some tip rollin'? I first tried out the medium silicone tips. Instant no-go for me, as I lost the Comply tip's great seal/isolation and thus noticed some reduced bass impact and depth. Next I imitated @Dsnuts tip mod the best way I could: as instructed, I used the small silcone tips backwards with some wider bore tips from my smartphone's IEMs (I don't have many other tips). Seal was better than what I had with the medium silcone tips but still not quite as good as the Comply tips. Sound-wise, the bass impact was a hair short of Comply's level. Additionally, although I wasn't sure if it was all in my head at this point, vocals seemed to be subtly airier. Subtle trade-offs. Still not enough for my typical taste, as vocals still sounded somewhat muted compared to the X00 (and thus the 400i). Therefore, I'll stick with my description of these as dark in tone and continue with the Comply tips.**
    -Although I highly doubt there will be changes to report at any later point, I'll be sure to update if I hear any from even more listening hours-  [Derp! At least I'm following up. EDITS added below]
    ***EDIT {Added 2 Days after posted review}: I'll tell you what...because I always want to be honest to myself and others...I have to say the darkish signature of the HEM6 is so intriguing to me. I still stand by my comparisons and notes above, but when I stop comparing the HEM6 to any of my other headphones, there's a way its presentation grows on you. Still very un-fatiguing and relaxing but you also start to feel like you're not missing out on anything in the music. Call it the wonders of our brains or what you will, but it's becoming such a uniquely capable listen to me. I really think if you're a fan of the Audeze sound (and maybe even something like the Nighthawk) you may really like the HEM6. If you're not or never thought you'd dig this sound profile, like myself, try to keep your mind/ears open and they may just surprise you like they have might not have been the sound profile I "wanted" but it might be what I "needed." Given the choice, I'm starting to no longer feel that one should discount the HEM6 for the HEM8...yeah...the HEM6 seem to closely approximate my "endgame" sound signature.
    ***EDIT 2 & Last One {Added 4 Days after posted review}: After careful consideration and more listening, I've updated my rating from a 4 to a 4.5 out of 5 stars. In theme with my first EDIT, the HEM6 have changed how I perceive my music/audio, for the better. Well frickin' done NuForce.
    Thanks for reading. Hope it was useful. Enjoy your music! [​IMG] 
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