FiR Audio M4

The oft promised but delayed multiple times M4 review is here! First a UPS delay in getting this to me from France, then a trip to FiR for a grill repair, and finally a delay over the Christmas holidays (I got the wrong priorities, I know, y'all told me that enough). Then another minor readjustment to play around with volume. While FiR didn't officially drop their mascot Firry until the release of their EDC 5x5, I think it's oft to make a reference in the title here. While Elmer Fudd may have been utterly befuddled and exhausted chasing around Bugs Bunny all day, Firry does not. If anything Firry leads you around on a musical energy that you come out of refreshed and ready for whatever 2020 part 2 wants to throw at you.

Preamble:
I've always been weary of dipping into brands that have a small selection as the price of entry tends to be higher either by virtue of the tech being expensive in production costs or simply a cash grab at times. Initially FiR fell into that category (a lack of reviews for the longest time wasn't helpful either. Also we do not talk about my blind buys!) despite being started by a Belonozhko of 64 Audio fame (and we know how I feel about 64 Audio ....and Empire, No those are not love letters to Vitaly and Jack!). My interest was piqued by the comprehensive review that @Wyville dropped and cemented by @Deezel177 's series about their line up. Either way, I would be getting mine second-hand as I this would be a blind buy. At the time I had obtained the Andromeda 2020 recently and despite my initial impressions, I really didn't see it being something I would listen to in the long term alongside the DMagic and MEST (Which I shortly moved after getting the Odin). So up the Andro went while I searched for an M4 to show up. @Fabaaroan eventually reached out for a trade via PM and the rest is history. Before boxing it up to FiR for the repair, my short time with the M4s impressed me. This was only the second fully tubeless design after the Trio I had heard, but it definitely my belief that open hat BAs and acoustic chambers is a direction iems should be going while estats mature as tech.

Design:
First things: the shell. I'm on the fence on whether manufacturers should stop using acryclic shells once you get past the $2k price point. I understand durability and all that, but it's going see increased signs of wear in comparison due to the weight and the shells crashing together more often, then there's the increased weight that may affect the fit or whether it'll fall off you ears. The though of the internals banging into a hard shell really does worry me sometimes. That said, the driver count is a huge factor and in models with lower driver counts this becomes less of an issue for me (Andro and Trio come to mind as well in that vein). I've always had an issue with the fit of the u12t and I wasn't too sure whether the M4 would be an issue in this area as well since the shells looked very similar. To my surprise, it did not. I put it in my ears and it....just stayed there. Not even my problematic left ear could find a complaint. The stem itself is not as angled as the u12t and I suspect in comparison with a lower weight due to a much lower driver count resolved the issues I had with the 12t before I even started to listen. One box ticked! I also have to mention that these have nozzle lips! Double lipped as well ensuring a very secure fit on tips. My second biggest complaint with the 12t was the lack of a lip to hold on to tips, having tips coming off in your ear is no fun. FiR seems to be taking feedback in their designs as well. Colur me super impressed!

Testing thoughts and so on:
Onto source: For consistency's sake, the review is based primarily on my 1A in 3.5 on low gain with variable volume (more on that later) and compared on my RME ADI 2 in case power was an issue(This is a new step I've been doing). As my impressions are based on the stock cable where possible and my Scorpion-C was 3.5, I opted not to do the impressions with my PWA Monile which is paired with the M4 on the 4.4. I'll do a small blurb on the effects of this pair up as well.I found the Radius Deepmounts in small to be a perfect fit and those have stayed on there straight out of the box. The last thing is the variable volume, I mentioned here a week or two ago that I was playing with the volume. Whereas with all my prior iems I had the 1A at one volume and stuck with it, I found myself changing the volume up and down depending on song with the M4, a very interesting point, but I found adjusting the volume actually got me more enjoyment out of a track as opposed to a consistent volume.

Bass:
The M4 leaves no doubt that the bass is DD unlike some select implementations. There's plenty of power and physicality to go around and the slam leaves a crap eating grin on my face whenever I put this wabbit in my ears. The clear subbass bias in the tuning establishes the M4's credentials in the subbass extension area and suit's my bass preferences to a "T". While not as fatiguing to my ears relative to midbass biased tunings, the M4 is by no means tame in that area. Rather it allows the M4 to showcase it's chops in the subbass which isn't allowed to shine as much with a mid bass bias. The bass is well controlled as a coherent whole with a bass shelf that prevents bleeding into the mids, while normally the end result is a slight recession in the lower mids the slightly warm and good body of the bass as whole prevents that from happening and shores it up. I'm happy to say that this is the latest in a line of hybrids where I haven't picked up any coherency issues. My biggest compliment though is for the feel and positioning of the bass on the M4 which always feels to in the exact spot it's meant to be. While the Tactile Bass might come across as marketing, I feel that this is a huge contribution to this feat. It definitely is more tangible to test when you compare to say the MEST's BCD.

Mids:
This is where it gets really interesting: As those of you that have heard the Trio/Fourte can attest, even if it's a single BA driver, tubeless mids truly sound magical. I would describe the M4's mids as slightly recessed though not as much as the u12t. They're not as full as some would like, but the ease with which the M4 provides separation,clarity and accuracy without losing musical coherency is something that needs to be emphasized. As a result of the tuning, the lower mids have a slight recession, but the slight warmth and body of the mids more than makes up for that. For those of you that have been disliking the upper mids bias tunings, the M4 is a good choice, it's very similar to the u12t and tastefully done. At the same time it more than satisfies the needs of an upper mids manaic like myself. Vocals male and female both come across clear and balanced and are treated equally with no bias. Some may find the vocals too recessed if forward mids are your thing. I normally prefer to enjoy my songs as a cohesive singular presentation rather a bias towards one of the ranges, but the M4 is prefectly capable of having the vocals carry the entire song, in fact I find myself getting lost in the vocals often during my sessions with the M4.

Treble:
Fir tops off this iteration of Firry with a very well extended treble, overall treble is natural and airy. Sparkle is well executed and balanced, I never had an issue with too much sparkle even when dialing up a Galaxy Supernova. With the exception of a lower treble peak that may bother some of you (No issues here with Firry myself), I really can't find fault with what is essentially Tia treble. It's not as smooth and dark as the u12t and injects some excitment and air into the presentation in comparison making for a much more enjoyable listen in terms of musicality.

PWA Monile Pairing:
With most comprehensve reviews of the Monile only surfacing recently (@Dezeel 's dropped a day after I bought mine from Musicteck), I bought the Monile on a whim based on the limited feedback available in hopes of tweaking my "biggest" concern of the M4: the forwardness of the mids. With the Monile as the permanent cable on my M4, it's safe to say that worked out. The bass and treble have remained relatively the same, with the mids being bought more forward it brought a bit more of musicality. I actually found the M4 being more prone to volume adjustments between tracks than with the Scorpion C. A concern I had with the extruded mmcx sockets on the M4 was actually not an issue. Compared to extruded 2 pin sockets, the difference is miniscule and I had no issues with looping the Monile over my ears.

Bonus Round (Stole this from Cinema Sins)U12t Comparison:
If anyone watches CinemaSins on Youtube, they do a bonus around every now and then. So I figured it was appropriate to nab this for this specific section. Like many a(n) u12t fan (probably all of them), after discovering DD bass desired a hybrid with the mids and treble of the u12t. @Wyville drew a lot of similarities and @twister6 teased that with his infamous picture. So naturally when I did get my hands on the M4, it would be u12t comparisons all around. When you take look at the FRs of the M4 and the u12t, they're eerily similar, but when it comes to actual listenig, the differentiation becomes more clear. So the million dollar question: Is the M4 a combination of the u12t's mids and treble? Yes.... and no. It comes eerily close in the bass and mids, but draws a bit apart in the treble. The M4 is more like a DD with the u12t's mids and treble tuned for musicality. It compliments the more technical and professional sound of the u12t rather than be a hybrid version.

Conclusion:
The M4 is an interesting proposal: A setup like the 64 Audio Fourte but at half the price. Having never heard the Fourte (I hope to one day), I can't say how the 2 compare, but it speaks for how far fully tubeless designs have progress with the trickle down to "lower" priced models. Granted it took a spinoff from the company not called Sony (M9 is tubeless iirc?) for this to finally happen. It's a U shape signature without that notorious lower mid recession that plagues iems with this tuning allowing it to be a contender for the elusive all-rounder category that I've been seeking myself (KuroKitsu, you have the Odin and A12t though? Yeah but....). I'll let some other respected gents in the community speak for me here:

@Wyville said " I can’t really fault the M4. Contenders in the category “desert island IEMs” (if you can only bring one set)? I think so."

@Deezel177 also adds "...FiR’s M4 is a strong all-rounder that leans towards articulation and clarity, but remains largely, impressively colourless as well."

I'm inclined to strongly agree with both of them The M4 has a strong technical foundation that shows but with a mind for fun compared to other technically inclined iems. It doesn't strike a compromised or a "balanced" tuning, it has an excellent technical chops AND it sounds musical. The fact that I've considered the M4 to be the "endgame" before circumstances got me in my current "predicament" with the Odin and others speaks monumentally to this. And for FiR to drop something like this as part of their debut setup? Bravo FiR, chasing this wascally wabbit has been fun and not fatiguing in the slightest. Looking forward to the other Firrys joining your stable in the future!

FIR Audio M4: the sound hyperrealism

Hi friends!

I am glad to inform you that today we continue our acquaintance with the line of in-ear monitors from the American brand FIR Audio! Today our guest is the second oldest model, if you count from top to bottom from “M5”, which has already caused noise in the audiophile environment - FIR M4.

Like all IEM / CIEMs of the FIR brand, the M4 has a hybrid design: here, as you might guess from the model name, there are four drivers (1DD + 3BA). In addition, there is an integrated Atom-X module inside and a unique "Tubeless Design" enclosure design. This is a patented FIR Audio technology in which they have managed to eliminate acoustic tubes as well as separate driver chambers. In such solutions, the most accurate calculation is necessary for the correct location of all audio components inside the IEM / CIEM, otherwise re-reflections and resonances cannot be avoided. But the FIR company with honor bypassed all the "pitfalls" and gave an excellent result, and for that it has a special respect.

I understand that with the current, not quite healthy pursuit, organized by a number of brands and their marketers, for the number of drivers in IEMs and the desire to "stick more inside a small box", in a small IEM case, the number four may seem modest, but I assure you , do not jump to conclusions. After all, the recipe for good sound is not in the number of drivers, but in quality, skill, technical literacy, implementation and, which is very important, taste and understanding, the feeling of sound by the manufacturer himself. And the FIR M4 proves it convincingly!

Well, if after this review you will be interested in other FIR Audio developments, then on our website you can also get acquainted with their M5 and VxV models.



Specifications
3D-printed metal shells
4-driver tubeless system (1 x dynamic driver, 3 x balanced armature drivers)
Range: 10Hz to 20kHz
Impedance: 6.4ohms
Сable 1,2m, with MMCX connectors

Unlimited Sound: CIEM or IEM?

Before starting the review itself, it is worthwhile to dwell on the fact that in-ear monitors of the FIR Audio brand can be ordered in both universal (IEM) and custom (CIEM) versions - the choice is up to the buyer. The exception is the VxV model, which is produced exclusively in the IEM body.

Well, for those who have not yet encountered CIEM, I can assure you that the procedure for ordering individual CIEM is not at all difficult. You need to go to the website firaudio.com, register, go to the "Designer" menu, select the desired model, its design (appearance, connectors, cable length) and pay for the purchase. Then you go to the hearing center, make impressions of the ears there and send them to the manufacturer. After that, look forward to the arrival of your exclusive CIEMs.



In our case, the M4 model is made in a universal design. And now it's time for us to go directly to the acquaintance with this four-driver miracle!

Appearance kit and ergonomics

M4 comes in a small black cardboard box. On its front side, in gold embossing, the FIR Audio company logo is depicted in the form of protruding bunny ears, from which sparkling sun rays scatter in all directions. Nice, perky and tasteful, well done!




In the box we find IEM encrusted in a foam base with a removable cable (MMCX / 3.5 mm) already installed, a stylish black leather case-washer with an embossed brand logo, intended for storing and carrying in-ear monitors, instructions, a warranty card and interesting colorful stickers ...

Inside the case neatly fit 4 pairs of silicone and one pair of foam tips, as well as a brush for cleaning sound pipes.





In general, the kit is from the category "everything is here and a little more."

The elegant black M4 IEM shells, including the aesthetic champagne faceplates, are made of aluminum. On the left faceplate, we again see perky protruding bunny ears, on the right - the name of the model "M4".

Everything looks very nice and stylish - this approach in design is very close to me personally.

The elegant teardrop-shaped IEM housing is lightweight, durable and extremely comfortable. It is smooth and tactile to the touch. The straight sound pipe is covered with a metal mesh that protects the IEM from moisture and sulfur. On the upper side of the shell there is a connector for a removable cable. Next to the connector are two tiny holes: an integrated Atom "Air Transfering Open Module" and a compensation hole for setting up a dynamic driver. It is pertinent to recall here that the M4 uses "Tubeless Design" technology: there are no acoustic tubes and separate chambers for drivers.
The ergonomics of the headphones are great. Wearing expected behind the ear.




Coffee-colored braided cable made of silver-plated copper litz wire. It is glossy, elastic, MMCX connectors, with a 3.5mm TRS jack and a splitter in the same style. The cable length is 1.2 meters. If you wish, you can replace the cable with any other with MMCX connectors, although personally I find it very pleasant.



As I mentioned earlier, the M4 has a hybrid design and is built around four emitters: three (BA) and one (DD) with an integrated Atom module. Here it is necessary to clarify what the Atom-X is - it is a metal cylinder-valve that acts as an acoustic filter for fine-tuning the sound of headphones. It also releases the air lock that forms between the earpiece and the eardrum. This way, the pressure on the eardrum is reduced and our hearing is not exposed to any risks. In the universal IEM shell, the valve is built into the headphone structure. We have the same case.

Perhaps the only thing I would find fault with is the MMCX connector. In my experience, such a decision often caused disconnections, although, of course, I understand that the company wanted to please many audiophiles who like to play with their collection of cables. But then why wasn't the more reliable 2-pin connector chosen? Moreover, FIR Audio has its own wonderful RCX connector / connector that they install in their CIEMs, and personally I really like it. I think that soon the universal version of their in-ear monitors will move completely to the new RCX. However, these are just my quibbles and it is worth seeing how the MMCX connection behaves this time.



Well, the kit, appearance, workmanship and ergonomics of these IEMs evoke extremely positive emotions in me, but, of course, we gathered together mainly to experience the main magic of the FIR M4 - let's move on to the sound!

Sound impressions

The listening was carried out on the equipment: MyST DAC 1866OCU V.2, Lotoo paw Gold, iBasso DX220 (AMP7), iBasso 220 MAX, QLS QA-361, iFI micro iDSD BL and iFi ZEN DAC + ZEN CAN.

Initially, FIR M4s were burn-in for 40-50 hours.

With all sound sources the M4 sounded good, their "voice" varied slightly depending on the sound source and the tips used.




I highly recommend choosing tips responsibly, as they make a significant contribution to the sound image of the M4.

There is another important feature of the M4. The sound of these IEMs is decisively dependent on the power of the sound source. The better the audio path and the more solid the amplifier, the more M4 is able to show itself in all its glory.



The sound of the FIR M4 is clear, well-balanced, open and unusually melodic. This is a light U-shaped frequency response, with a neatly accentuated subbass area, and light, elegant emphasis in the high-frequency register. These IEMs demonstrate excellent dynamic range and stunningly convey volume, and in it the localization of apparent sound sources in space: higher-lower, further-closer - clearly and scrupulously building a virtual "sound stage".

This is realized so skillfully and at the same time artistically that you no longer just listen to music, but begin to see every sound in the enchanting three-dimensional image that appears in your head. The immersive effect is such that at times it seems that you can touch this or that musical instrument and even the sound itself flowing from the instrument.

I called this sound magic the M4s do "sound visualization!" When musical images are built, as if in a picture of hyperrealists, with crazy detail, amazing volume, extreme harmony, layering, giving out excellent melody at the output. This is somewhat reminiscent of the sound of a studio monitor with an AMT tweeter. Precise, clean and neutral, with a slight elegant coloration in the lowest and highest registers. Moreover, the Highs here in some places are served by a "spectacular spark", which, like a sparkler, flares up, illuminating the space around itself, and scattering into small specks-stars, sharply fades away, falling into the darkness. Incredible beauty!




Low frequencies are transmitted tightly, accurately and quickly, with good texture and excellent articulation. There is a crisp clap, a tight, biting beat, and a textured nimble bass. It should be borne in mind that the lower case is not very forced, it takes more quality than quantity. The rolls of the drum set blows, like artillery shots, scatter on both sides of the listener, accurately conveying the force of the blow. The density and speed with which the M4 is working out lowercase is simply amazing.

The bass is fast, punchy and extremely naturalistic. It is presented in a lively and temperamental manner in a neutral manner. There is not even a hint of rumble and booming, but there is precision in the reproduction of timbres combined with excellent balance.

The mids are clear, like a mountain stream, neutral and smooth, with excellent texture and excellent resolution. The M4s showcase excellent detail and astounding visualization of sound images in a space with detailed, holographic sound delivery, where no detail escapes the listener.
This is a well-balanced and at the same time emotional performance, where all the elements of the composition are presented with extraordinary precision, large and versatile, with amazing smoothness and informational content. Strings and wind instruments sound clean and distinct, and the vocal parts are transmitted smoothly, naturalistic, very beautifully and moderately expressive. This is a fairly harmonious, spacious and very musical manner of performance.

And here it is simply necessary to return to one of the most important advantages of the M4 - the transfer of the volume of virtual space. Sounds, as if by the wave of a magic wand, as in a three-dimensional image, are scaled and lined up, both in the head and beyond, into a multifaceted harmonious canvas, on which, with the help of sound and imagination, we can build our idea of the spatial form of a sound wave. so to speak, to revive what was heard. And this is just an amazing quality - aerobatics!

High frequencies sound quite clear and intelligible, refined, with good articulation and enviable correctness. This manner of HF processing is a bit like the transfer of this register by an isodynamic or AMT driver. There is a slight accent in the form of a light crumbly spark with a slight brightness.
On the one hand, in this case there are no exquisite after-sounds, on the other hand, it is this manner that gives the overall sound of originality, expression and charm. It is worth noting the fact that with a generally rather comfortable manner, in some poorly mixed and overly bright compositions, such a feature can lead to minor problems and unobtrusive sibilants. Although, in all honesty, I want to say that it still sounds effective, beautiful and comfortable.

In fact, I noticed that this property of the M4 directly depends on the quality of the sound source. If we take a better path and a more powerful amplifier, everything is flawless with the Highs, only the advantages of this frequency range are audible: its peculiar, euphoric manner, which definitely catches me.

By the way, the selection of the sound source also has the most direct impact on the transfer of volume, width and depth of the virtual "sound stage".




In terms of genre preferences, in my opinion, FIR M4s are quite tactful: they play interestingly as classical music, instrumental, jazz, electronics and rock. In principle, things are also pretty good with brutal genres, but it depends more on the quality of the mastering of the compositions. Well, these IEMs play classical music and jazz just great!

Conclusion

M4 - amazing in-ear monitors! FIR Audio mixed in one cauldron exceptional technical competence, impeccable taste and brilliant ideas, and on top they also clearly seasoned it all with a miracle potion. As a result, we have before us “TOTAL IEM” - a model that, in my opinion, deserves the closest attention of all who dream of an exceptional sound.
Such an exquisite audio signature, in my opinion, is able to satisfy the needs of the most demanding music lovers and audiophiles.

You can order the FIR M4, like any model in both (CIEM) and universal (IEM) versions, on the official website firaudio.com for $ 1899.
Yes, the price is not small, but that is how much the sound costs, from which it takes your breath away, and the imagination is turned on to the fullest.

As you probably already understood, I recommend these earphones for purchase without the slightest hesitation.

I had the chance to demo this IEM for about 2 weeks by participating in a loan tour, organized by a member of the community. I would like to thank him for the opportunity !

As a disclaimer, the sources used with the FiR Audio M4 are the iFi Micro Black Label and Sony NW-WM1A. I found the M4 to be fairly resistant to hissing, which makes it quite versatile with sources (big bonus if you're not sure your DAP or DAC/AMP is quiet enough). I also found the comfort to be quite good for long periods, as I did not get any pressure build up whatsoever. Stock cable is quite good. It is pliable, but not the softest. Feels good on the ears, it doesn’t itch or anything.

The music I listen to tends to be quite vast, but it mostly revolves around metal, rock, instrumental and soundtracks. Here is a non-exhaustive list of the bands I used to gather my thoughts : Dream Theater, Haken, Jinjer, Opeth, Tool, Gojira, Killswitch Engage, Lamb of God, Breaking Benjamin, Chevelle, Soen, Karnivool, Andy Timmons, Marco Sfoli, Anup Sastry, Intervals, Plini, Animals as Leaders, Hans Zimmer and Ramin Djawadi. I feel like rock and metal are the best genres for this specific IEM, but the somewhat "relaxed" treble response might not work with everyone.

As far as sound goes, some things sound amazing, some things don’t sound really good. I'm not sure I would say it's a great all-rounder, simply because it does not go well with every genre. Sound signature was fairly pleasant (not harsh) overall, with excellent bass (sub bass is excellent, mid bass is good). Probably one of the better performer in that frequency range. The lower mids have a nice texture and timbre to them. Distorted guitars sounded great ! Vocals are definitely a bit laid back, they sit a bit at the back when compared to everything else in the mix. Not the best detail out there, can lack definition on more complex and complicated tracks. Some instruments just aren’t well reproduced (piano, bass guitar), due to speed mostly. Seems like the drivers can’t keep up. Much better at higher volume, but performance is not that great if you keep the volume fairly low.

Recommended for the price? If you really just want to relax while drinking some whiskey, then sure. The bass response is impressive. But, if you prefer to do some critical listening, then no. A bit on the pricier side of things, would be more competitive at a lower price point (something around 1.3k-1.5k usd), because I would probably take the Solaris or U12t over the M4.