UM MEXT Review: Enter the 4th dimension

THE PLUS:
-Smooth crisp and immersive musicality
-Exceptional resolution
-Organically Cohesive tribrid tuning
-Richly detailed mid-range with focused presence
-Fast snappy treble with tremendous micro-details amount
-Nice transparency
-3D spatiality with fully present center stage
-Great imaging-layering
-Realist timbre
-Excellent all-arounder (even including gaming and movie watching)
-authoritative bass with tactile weight
-their nothing that sound like the Mext
-more musical than Mest MK2 (subjective)
-good cable, nice case and very welcome Azla eartips

THE MINUS:
-bass is a bit warm in definition and resolution compared to mids-treble
-lows are mid bass focus, lacking deep linear extension
-timbre is a hint compressed in density
-lack of air in overall spatiality
-capricious fitting to achieve supreme sound experience
-overly tight 2pin connector with rounded edge

TONALITY: 8.8/10
TECHNICALITIES:9.5/10
CONSTRUCTION: 8.2/10
MUSICALITY-VERSATILITY: 8.5/10
SOUND BENEFIT: Very Noticeable


(to note: No borders Audiophile don’t give score for sound value when it come to products above 1000$)

UNIQUE MELODY doesn’t need presentation since they are well know but let share a little about their story.
UM is a chinese based audio company that started in 2008 as an hearing aid company, 4 years later they become an official IEM company aimed for audiophile. The experience they earn in hearing aid CIEM molding as well as balanced armature implementation have sure been of great use for their start as well as futur recognition.
UM have a wide range of IEM in their catalog, mostly hybrid and tribrid. Their IEM price range go from 300$ to 6000$, and aim high end audiophile with rather good amlount of money to invest in their passion. I did test their ”budget” iem in the past, the triple dynamic driver UM 3DT and enjoy it quite alot due to it’s energic and full bodied musicality that sound like any other IEM I heard before, thanks for well implemented and high quality DD’s used.

Logical step from here would have been to test second most affordable IEM, the Mini Mest, but it seem i will go for a more exotic tribrid call the UM MEXT.

Priced 1100$, the Mext is a 6 drivers tribrid UIEM using 1 dynamic driver for bass, 2 balanced armature for mids, 2 BA for treble and a OBC (original bone conduction) driver for upper low to mid treble (200-7000hz).

As said: exotic.

Let see in this detailed review if the Mext hold it’s ground with such an audacious drivers implementation and more importantly, if the tonality is well balanced, cohesive and deliver an accessible musicality.

CONSTRUCTION

Firstly, UM offer 2 version of the Mext, a custom one at 1400$ and universal fit for 1100$, i do think it worth paying extra 300$ for this very kind of earphone since bone conduction driver love tight fit that permit the shell to be in contact of your inner ears. My version is Universal fit and the right fit can be a bit capricious, i will explain why here.

The Mext have a big chunky housing, made of smooth medical grade plastic resin, it have an ergonomic shape with short but big nozzle. For the number of driver it use, the shell doesn’t seem oversized, for example, my Muse Hifi planar IEM is bigger and if i remember correctly, the Mest Mk2 too is bigger. Overall quality seem good, but it’s not what I would call a looker, nor the most impressive built in this price range. On top of body it have a 2pin connector and this is where my nit picking will hit: like the UM 3DT, these 2pin connector are ultra tight and prompt to break pin connector of your cable due to how it’s placed on the curvy plastic housing, it make it very hard to connect some cable due to (blind) perfect alignment need. In fact, i barely broke stock cable very first time i try to connect it and pins get bended, with other cables, their some im unable to fully push the pins inside the housing which is worrysome.

(3 ear tips I love with the Mext: Azla, KB07 and FLC wide bore)

Now, when it come to fit, the included Azla ear tips sure help but i suggest you to try all wide bore ear tips you have in your collection like I do, since both fit and seal will greatly inflict on how open and balanced will sound the Mext. The IEM are light and comfy for me, but with some ear tips it might be too big for some smaller ears canals. Simply put, don’t use too stiff or hard ear tips with the Mext for long time listening.
But insert it as deep as you can too! Which isn’t very deep since nozzle is short, so it’s not gonna be uncomfortable, but the part of ear shell that have the OBC driver will be in better contact with your body, which greatly inflict on sound resolution and richness, as well as vocal presence fowardness etc.

When it come to PACKAGING & ACCESSORIES, it’s generous enough even if it come in an understated small box. I’m not very sensible to fancy presentation so I can’t honestly complaint here. It’s nothing to write about, yet doesn’t feel underwhelming.
Accessories are quite generous and included a very beautifull carrying case of excellent craftmanship, it’s rare that i focus on carrying case but this one seem to be a looker since my ex girl friend ask me to give it to her. t’s big enough to put other things than the Mext too.


For me most important accessories is the CABLE, and I was rather underwhelmed with the one included with UM 3DT so this is a very positive surprise to have a good quality 4.4mm balanced cable this time!

MEXT is paired with UM Copper M1 custom cable manufactured by PW Audio, it use OFHC copper that promise smooth pairing. It’s a 4 cores braided cable, quite light and smooth with a very impressive plug quality, perhaps the best ive seen in fact, heavy and thick with mate black finish and UM logo, very nice. When it come in sound pairing, this smooth dynamic and make tonal balance more organic, a pure silver cable like Tri Grace S will improve clarity for example.

Rest of accessories are quite interesting too, star of the show being the ear tips included which are the famous Azla eartips, a sticky wide bore silicone eartips that will solve secure fit for some. You have UM silicone eartips too. A cable holder, a cleaning clothe as well as extra screwing mesh are included too. Pretty good.

SOUND IMPRESSIONS

(Gear used: SMSL SU-9 DAC+SH-9 AMP, TRI TK2, Questyle M15, Xduoo Link 2 Bal, Ibasso DX90, Tempotec E44, Xduoo Poke2)

The UM Mext is so unique in sound rendering that it’s perhaps the hardest critical listening review of an earphones I ever made, so be ready for a very wordy one that will try to cover all acoustic aspect including bias of psychoacoustic that more than ever come to play in final sound impression.

Why? Because the Mext litterally transmit sound in your mind and ”out of your head”, due to the bone conduction driver that can’t even be measure using a normal mic. It mix both physical sound vibration from soundwave to your eardrum and bone vibration directly to your cochlea, this mean the OBC driver act like your eardrum by transmiting soundwave info that got directly decoded by the cochlea, which will do final job of transmiting vibration to your auditory nerve. This explain why the Mext is vibrating when you hold it in your hand. The advantage of this type of sound conduction is that it bypass the eardrum that have limitation, not just due to imperment but to aging too. But what is unique here, and mind buzzling, is the fact the Mext doesn’t ue OBC to extend treble hearing up to 20khz or above but to magnify clean detailed presence of 2khz to 7khz frequencies range.

I was worry that this exotic tribrid drivers implementation will deliver an artificial sound experience, or suffer from timbral or tonal imbalance but in fact everything is organically hold togheter with the OBC driver acting like a center stage added sound layers as well as magnificator of timbre nuance and well define instruments singular presence. It’s so well done that at first you don’t even think their bone conduction driver nor multiple balanced armature since it sound like a ”magical dynamic driver” with smooth and crisp W shape tonality and a beautifull bass boost. But more you listen to the Mext, more you get immerse in it’s unique musicality and discover how richly detailed and dynamic it sound. As well, in my case, I discover that ear tips play a very big role to achieve proper openess of soundstage as well as boosted mid and lower treble presence which is inherent to the fit which need to be deep enough to be in contact with inner ears helix that is near to jaw bone. Do the test, you’ll see that female vocal can be either a bit recessed or upfront depending of how perfect is the fit, this can be seen as nit pick drawback since I do find the Mext capricious about both fit and ear tips choice. For ear tips, the included Azla are good, especially for secure deep fit since it stick into your ear canal, but i do prefer shorter wide bore ear tips which tend to make spatiality wider and taller, improving spacing in instrument separation too.

Before sharing detailed sound impressions, let me tell you that the Mext are very transparent to source and will scale up with better DAC quality as well as clean amping. While not very hard to drive, i would suggest a minimum of 300mw@32ohm power for them, but even dongle like Questyle M15 and Tempotec E44 (170mw@32) is plenty enough. So, i do believe the sheer sound quality of your source is most important aspect to take full advantage of Mext high resolution capacity. If your audio source can deliver tremendous amount of micro details and treble dynamic, the Mext will offer a very rewarding listen immensily generous in sounds layers and infinite level of details. For this review, the Mext show it’s full potential with the SMSL SU-9 ES9038PRO DAC paired with SMSL SH-9 THX amplifier, which offer ultra transparent, clean, open and detailed sound with crazy attack timing and ultra snappy treble, as well, texture is more detailed and bass less warm. I do use Questyle M15, Xduoo Link2 Bal and Tempotec E44 for hours and hours with the Mext too, all delivering a very potent sound experience. I do think that at 16ohm of impedance and average sensitivity of 108db, the Mext is easy to drive but benefit from a clean source with a low impedance (under 1ohm).



NOW for the sound.

I would call the tonality of the Mext as crisp yet smoothly balanced W shape, some would call these neutral but their a slight bass boost here, far from basshead level but still, it have extra warm slam to it with elevated sub-bass rumble. Tonal balance is cohesive, organic and densely in transparent sound layer, their an understated analytical side to Mext tonality, since it deliver high level of micro details and texture nuance effortlessly.

We can say that bass part is what add the most physicality to Mext sound, while mids and treble is quite technical sounding, the low end is warmer and less textured. It’s a chunky well rounded bass that doesn’t distract you, yet make you shake the head with it’s thick slam. You have the oomph that add heavyness to the music experience as well as the slam, not so much of a tight thumpy bass with well define kick drum presence nor the fastest clean attack. Here the resonance embrace lower mids and thicken the timbre without swallowing the instrument or vocal presence which are extracted and fowarded by the OBC driver. So did it mean the bass quality is bad? Not at all, but it’s not a technical nor a bass canon performance, it’s a warm and vibrant low end with thick rumble, not very linear in extension. Contrabass, like the one of Lars Danielsson in ”Tarantella” album, have good texture grip yet when it come to natural resonance presence its more bloomy, opaque and warm in resolution, it add physicality to most low end instrument yet can transform into a rumble something that should have lean resonance. When it come to pure rumbly sub-line like in the basshead song ”Moonlight” from IAMDDB, the sub line are warm and chunky, quite dense and opaque yet not very flexible and well articulated so it affect subtle tone change as well as loudness variation which should be more curvy and less slow in transient.
The bass of the Mext have softed edge ot it’s definition, but stay in the back of other instrument with well rounded body and great sens of physicality, depending of audio source, bass line and kick drum can have good texture too in presence, which is amplify by bone conductive driver, so this make the bass uniquely in it’s presentation and add a sens of immediacy to a full bodied attack.

I tell you this review would be wordy, and now their go the hardest part of sound description: the mind blowing (and boggling) mid range. Crisp, clean and tremendously detailed, sitting between lush and bright with a near surnatural transparency to it, the mids are smooth in dynamic yet vivid in details and free of any sibilance, it’s clean and translucid like shiny water where you can see every tiny wavelet without sun reflection affect transparent so you can plunge into infinity of colors and details nuance.
The vocal have an intense sens of proximity to the listener, which work excellent for female vocal that don’t need as much body presence as male vocal which have clean and immediate presence but feel a bit less full in body than female due to lower mids not being very boosted and quite lean. The magic here is coming from OBC driver that stamp extra presence and details to every instrument, boosting resolution without any agressivity or tonal imbalance. That kind of mid range is impossible to create without the OBC trickery, since extra definition edge doesn’t interfer with other frequency in they air but are transmit to your brain directly. That feel like writing about a scientist experience but be reassure it doesnt sound clinical or artificial at all, it’s more like adding perfectionist colors details to a blank sculpture. Or boosting sens of transparency, since the Mext exceel in that regard, and it make whole mid range extremely informative about sounds nuance, singular layer presence, instrument texture richness and attack clarity.
What the OBC don’t add, is extra note weight or timbre thickness, mid range dynamic is vivid yet light in attack, timbre is dense but in a compressed higly resolved way. It’s realist because the edge isn’t distort with sustain-release.

The treble is like an effortless X-Ray device that extract every little details without creating ear fatigue or harshness, it’s again very alluring and intensely immersive. You have great sens of immediacy, excellent snap and gentle brilliance to it. It’s very very speedy too, yet the upper treble sparkle decay isn’t very present and sens of air seem a bit ”digitilized”. Since upper treble is deal with balanced armature, sustain cut short and their not ultra treble boost to add air or if it have, OBC perhaps modify my psychoacoustic perception about it. The Mext is the type of IEM that will extract micro details you never heard, and that even if I tell myself this with other IEM. Again, bone conduction driver come to add extra sound info in an inoffensive way, these little details are ultra clean and crisp and enrich whole sound experience, it doesnt affect timbral balance when it come to instrument texture. Violin sound very clean and detailed, highly articulated whatever the speed and with excellent transparency that will benefit violin quartet for instrument separation accuracy. The presentation isn’t lush, warmed or colored, more of vivid neutral with softed lower treble so you avoid unplesant brightness of violin when it play agressively. When it come to acoustic guitar, higher harmonic are a bit more focus, so you have a crisp presentation with fast attack lead, just enough decay and very high resolution. For electric guitar, it’s a bit less appealing since attack is smoothed in dynamic, making the euphonic distortion sound softed too and a bit muted, yet it’s well layered and keep it’s transparency even if a bit over saturated in texture. Percussions are very well balanced and not overly boosted, yet clean in details and presence and very speedy and snappy, their no splashyness nor treblyness with this singular treble performance.

The soundstage isn’t the most open and airy, nor the tallest or deepest, it’s quite wide and holographic but you feel in middle of the music here, not at some distance of it….your like in the middle of triangle room fullfill with speakers on 3 walls. It does lack some air to breath as well as some deepness due to dense and very numerous sound layers.

Strangely, this doesn’t affect the imaging negatively since both static positionning and moving sound layers are clearly rendered. Level of accuracy is high here due to center stage presence that permit to surpass a stereo rendering, so you can pin point better instrument and vocal in middle while left and right positioning extend the perception. Only the bass part can feel a bit blurry in definition making it harder to separate from mid and highs range instruments.

COMPARISONS

VS FINAL A8000 (1xPure Beryllium DD-2000$)

This is my personal end game IEM, and it isn’t a normal dynamic driver IEM, the DD in this is just insane in technical performance and having heard other flagship IEM like the Andromeda, UM Mest MK2 and 64audio U12T, i can assure you they have nothing to envy from them both in tonality and technicalities….so how the 2 times cheaper Mext will compare with it’s 6 drivers?

Well, firstly, the A8000 is more bright and agressive as well as more treble centric energic W shape. The Mext have more boosted sub bass, yet bass quality of the A8000 is notably better, both in attack speed and control, timbral balance and texture and clean fully extended lower extension, definition is better sculpted and have more mid bass punch and kick drum presence. A8000 offer best bass response I ever heard, and it’s not a shame to not be able to win in this department, so it’s time for the Mext revange with it’s special midrange that is way more foward in presence, making the A8000 feel very recessed suddenly even if a bit more meaty for male vocal, everything else is more upfront and not as boosted in upper mids, which can create rare instance of sibilance with female vocal with A8000. Mid range resolution is higher but timbre is a hint thinner, as well, vocal have more breathyness and are a hint more natural due to less magnify texture micro details. Note weight go to A8000, piano sounding fuller and heavier in mid section, yet not as crisply resolve and clean in definition.
The treble is an intense combat here since both excell in this department, the Mext have a more delicate and snappy treble, not as sparkly and full sounding as the A8000, which have more chunky crunch too. Again, the Mext deliver higher level of micro details, timbre texture is less abrasive and bright and overall presentation is more articulated in precise definition of each sound. Acoustic guitar have longer resonance with the A8000, as well as fuller harmonic, yet sens of immediacy is greater with the Mext.
When it come to soundstage, A8000 is wider but less tall and deep, the imaging is crisper and more accurate and precise but a bit more condensed in sound info since it add more layers to spatial occupation.
All in all, mid and treble technical performance are superior with the Mext, but bass quality is better with A8000 as well as timbre more natural and dense, offering a less exotic yet more realistically cohesive musicality.

VS FIIO FH7 (1DD+4BAs-500$)

Again, FH7 is more W shape and agressive, brighter in timbre and more wonky in tonal balance, it feel shoutier and harsher than Mext which is very smooth near warm compared to FH7.
Bass of FH7 is more focus on mid low, with faster tighter punch, it feel more detached from the mids and treble, less warm and euphonic. Sub bass is more rolled off and timbre is dryer with FH7 too.
Mids are unbearable compared to the Mext, way brighter and more sibilant, more compressed and centered, so less wide and well define in presence, vocal are more upfront with the Mext yet smoother, more textured, more transparent and less shouty.
Treble is notably more spiky and agressive with FH7….man, after this comparison i’m not sure to be able to love my FH7 again and it’s very sad, but this can be explain by my hearing evolution too which is now more sensible to spike and harshness….but let say details are scream at you, with fuzzy grainy sustain which can get messy with busy track while the Mext offer higher number of micro details, all well separated and free of loudness imbalance and fatigue.
Soundstage is notably wider, taller and deeper with the Mext, offering a more clean, accurate and precise imaging too, since transparency is not saturated like the FH7, only the bass instrument can be darker and harder to pin point, mostly bass hit like toms, kick drum.
All in all, it wasn’t a fair fight due to the Mext being 2 times pricier, but one thing sure the sound benefit are on the high side with the Mext and justify an urgent upgrade for a similar W shape tonality but way more cohesive, smooth and musical tonality as well as from another league in term of technical performance.

VS KINERA URD (2DD+2EST+1BA-600$)

First difference that hit me is in soudstage presentation, which is drastically different in spatial cue as well as notably wider and taller, but with scooped middle presence that add sens of openess yet make it more stereo sounding and less immersive and holographic than Mext. Imaging is less precise and fully restitue with the Urd, mid range instruments are difficult to spot which is one of highlight of the Mext.
This surely can be explain by 2 factor, the use of OBC driver to extrack presence of mid range as well as a different tonal balance that is more W shape and lean with the Mext while more U shape and warm with the Urd.
Strangely, the bass is a bit similar here, warm sub bass focused slam, round and heavy in hit but not very fast or precise, here the Mext have a hint better define presence due to slightly more textured bass while URD is bassier and a bit more dynamic in impact, perhaps faster too since fast chuncky kick is better articulate.
Mids are notably more recessed with the Urd, warmer and darker, a bit denser in timbre but more liquid too and lacking in definition edge make it more blurry and muddy, resolution of Mext being miles ahead here and offering both male and female vocal with more fowarded presence as well as crisper more accurate imaging as stated above.
The treble is brighter with the Mext, yet deliver higher amount of detail in a more balanced way while the URD focus on upper treble snap and air, boosting micro details a bit and offering a more delicate and coloured treble, with darker lower treble, so it feel half cook compared to more analytical Mext.

Here, tonality is so different it’s hard to choose a winner, URD is more laid back and bassier so it might be less distracting or fatiguing for long listening, technicaly it’s inferior in all department and feel less full sounding due to lot of darkened part in treble and mids section. Guilty pleasure for the Urd here, while confident pleasure for the Mext.

BONUS comparison (from memory) VS UM MEST MK2

Ok, I did have a good 2h listen of the MK2 but its make near 2 years….so, it’s to take with a BIG grain of salt, i just feel i need to at least share these memories.
Firstly, they are a bit similar but, but Mext is more energic and immersive sounding with a bass that have more weighty impact, while Mest have better extension and cleaner presense.
Mest is leaner in dynamic and colder in tonality, its airier and more open and deep in spatiality from what I remember. The treble while a bit thinner and less crunchy than Mext is more brilliant and sparkly.
Mid range seem slightly more recessed, dryer too, .
To some extend, Mest seem more cold U shaped while Mext more smooth W shaped.
As said, these impressions are not really legit, but i remember having issue with timbre of the Mest which i don’t encounter with the Mext.

CONCLUSION

I think it’s evident I have an overwhelming love affair with the otherwordly UM Mext, which is a big surprise to me due to complexity of making coherent this type of multi-layered sound experience with such audacious drivers implementation. Fact I can’t find difference between BA and OBC driver when playing music tell alot about how organicaly balanced is the tuning.

The UM Mext is a true End Game IEM with a versatile yet highly technical and musical sound, this is the type of IEM that make bass, mids and treble sound rich, dynamic and highly detailed, yet all focus in presence and well behave in attack control.

This can surely please everybody, bass boost lover, mid accuracy and boosted presence lover and most demanding treble performance seeker. The Mext nail musicality that Mest Mk2 was lacking, and offer an immersive sound experience like no other.

As a sceptikal about bone conduction driver potential, i’m now fascinated about incredible potential of this technology that can litterally change your hearing perception and enrich psychoacoustic sound exeperience to a next level.

Enter the 4th acoustic dimension, where both your mind and ears are fullfill with sound info, making every listen highly exciting and enriching, since you can dig in sound infinity with the Mext.

Highly highly recommended!

———-

PS: I wanna thanks Unique Melody for sending me this review unit. While i feel humble, i’m not affiliated with this IEM company, nor have any incentitive to write a positive review. UM will read this review once published like everybody else.

You can buy the UM Mext at lowest price (1000$) here:https://hifigo.com/products/umunique-melody-mext

For more info about Unique Melody IEMs, give a look here:https://www.uniquemelody.org/

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