64Audio U12t - Reviews
Pros: exceptional bass (effortless in speed, precision, balance), impressive treble with both sparkle and body, overall balance, helpful customer support
Cons: midrange is not tonally perfect but close, cable feels cheap, a bit large / heavy
It’s a bit hard for me to write this review, but I find it necessary — the 64 Audio U12t has been a major factor in my unexpectedly low level of enthusiasm in audio gear… but maybe not in the way you’d expect. Scroll down to Conclusion for a TL;DR.

It was a summer day in the streets of Los Angeles, where I found myself half lost looking for the entrance to CanJam Socal 2018. After buying and trying many IEMs over the prior two years, I had settled on the Campfire Andromeda as my personal portable audio paradise. Regardless, there were so many IEMs out there that I haven’t had the pleasure of trying. I was excited to change that on this day.

Two hours later, I was both a bit disappointed and relieved to find that every IEM I tried in the venue felt a bit underwhelming. With most of them, I caught myself thinking, “Meh, I prefer my Andromeda”. But of course, there were some standout exceptions that had me second guessing whether or not I was ready to settle — namely, the 64 Audio U12t. This IEM clearly stood out to me and managed to solidify its place in my mind, surpassing my beloved Andromeda in every single aspect I could imagine. And that was that.


2 years later, having gone through several different revisions and colorways of the Andromeda, I’ve finally reunited with what I feel is a long lost friend. The U12t retails for a hefty $1,999 USD direct from 64 Audio. As its name suggests, each housing sports a 12-driver setup featuring their proprietary tia drivers and standard detachable 2-pin 0.78mm interface.

The unboxing experience is professional and straight to the point; it’s not the most premium packaging I’ve ever seen, but very well organized and concise without seeming like an afterthought. You are greeted by a very well-designed protective carrying case, a variety of eartips, the U12t IEMs, and stock cable all neatly fitted into a dense foam cutout. Inside the carrying case you have access to alternative apex modules, a shirt clip, and a cleaning tool.

Build quality feels like it wouldn’t be an issue — the housings are machined to a smooth anodized aluminum finish; you can see slight inconsistencies in the texture but nothing visible from further than 6 inches. Coloring is consistent around the shell, with reasonably sharp L/R indicators on the inside face of the shell along with the unit’s serial number. They’re also a bit hefty and large, so those who have small ears or those who commonly find issues with IEM weight may be turned away from the U12t.

One thing to note is that the included cable feels a bit out of place for a $2000 product. It's a bit stiff and jumpy, doesn't look premium at all, and overall feels a bit awkward with its matte, 'papery' texture. That being said, those willing to drop this cash on an IEM probably wouldn't mind picking up a boutique premium cable either -- lots of good, affordable options out there nowadays!

Something I noticed is that the mesh filters are held in the nozzle by a strip of adhesive; I’m not sure what would cause this to deteriorate but I had an issue where the mesh was pushed inwards while using the included cleaning tool to remove some wax. I’d like to give 64 Audio’s support team a massive shoutout for helping me to resolve my case with nozzle filter, and making the warranty process absolutely seamless. You couldn’t imagine the look on my face when I realized that I had broken the nozzle of these expensive IEMs, so that was a massive sigh of relief.

The Apex modules have two notches cut into the sides to simplify removal. These can sometimes prove to be a bit tight, more commonly so in the carrying case than the IEMs themselves. I’d recommend taking it slow, as the edges of the module can work their way under your fingernails if you aren’t careful. They slide snugly into the module slots in the IEM with absolutely no room to spare, ensuring a secure fit without any rattling or play. The U12t comes stocked with a pair of M15 modules and a pair of M20 modules; the former in silver and the latter in a gunmetal shade.


In terms of sound, I’d consider the U12t to be an excellent all-rounder — it’s got exceptional bass response that reaches down effortlessly to the lowest of lows, ample-bodied midrange with solid note thickness / clarity, and a clear treble performance that feels both precise and full. Bass is built with an emphasis on subbass, lifted generously in the lower region without being weak in the midbass. Midrange is bumped up in the upper-midrange, but can occasionally sound a tad muffled in the very highest vocal registers with certain vocalists. Treble is full-bodied throughout with great presence, though it may lean towards what some may consider bright. Resolution is great throughout the spectrum, really demonstrating its technical prowess on any well-mixed track.


Bass, as mentioned, rumbles effortlessly at the lowest of my hearing range. To note, this bass presentation is super tight and textured; not a single beat is missed here. That being said, it doesn’t seem to have the visceral ‘eardrum pounding’ subbass that comes from some basshead dynamic driver earphones I’ve heard. However, don’t get me wrong — the U12t’s bass is no slouch, it’s tuned well above normal and slams hard when called for it. It’s hard for me to put into words, but the U12t’s bass feels very effortless. It’s as if the U12t can do what it’s expected to without a hint of sluggishness or err, hyper responsive and capable in its performance.


Midrange tends to be a very touchy region for most people — some like their vocals to be crisp and sharp, while some prefer a thick and rich vocal tone. From what I’m hearing, the U12t sits just slightly closer towards the former, lending a very clean and distinct tone that puts out note resolution and detail with confidence. Lower midrange is never bloated or muddy (something that eventually made me give up on Andromeda), and center midrange comes off with a nice weight that I’d consider just a very slight touch short of perfect. Vocals, while mostly natural, may lack a bit of high upper-midrange flexibility; they can occasionally sound constricted or ‘limited’ in the sense that the vocalist’s full note isn’t given 100% room to resonate or interact with the room. It’s close, but just not completely there. However, for most listeners (including myself), it’s very easy to see past this and enjoy the overall sound of the headphone for its other very strong qualities.


At one point, I considered myself to be somewhat of a treble-head (quality, not quantity!). Mostly due to being a huge fan of the Andromeda, and taking a particular liking to the high-end sparkle of that tuning. That being said, the treble on the U12t is incredible — it’s taken me quite a few IEMs to find one that I flat out preferred over the Andromeda, but this is without a doubt the number one contender. The treble is super crisp and resolving, and has a wide sense of openness and staging that still feels natural. Lower treble is also well-bodied and has a good amount of crunch, avoiding the overly aggressive or harsh brightness that is present with many other attempts at reproducing that elusive “sparkle”. Not once does the U12t sound muted, dull, or lacking in treble extension. I’d say that the treble performance is one of the U12t’s greatest qualities, just as impressive as its bass region with its sheer effortlessness and precision.

A Bittersweet Conclusion

I know it may sound cliche at this point, but the U12t has decidedly become my ‘endgame’ portable audio choice. I no longer find myself scouring the classifieds and second-hand market for my next potential earphone, spending countless hours on the web browsing the latest audio trends. It’s a little bittersweet, but in hindsight it marks a very significant milestone in my audio journey; the U12t along with the HD800 has left me with a sense of satisfaction in my setup, relieving me of the once-rampant audio bug. I finally feel content with both my portable and desktop setup, finally shifting my priorities to focus on enjoying the music rather than the equipment.

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@gLer I think that it comes to the personal preferences anyway (as usual :) ). You won't squeeze the same out of 30 BA as of a DD in certain aspects, but DD can't compare in precision, etc.
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Personally, I find that I like the feel of the U12t's bass -- as you said it all comes down to preference ... there is a time and place for DD bass as I first entered the hobby as a wanna-be basshead, but after a while the thump can be a bit much for my eardrums -- not quantity, but just how hard some DD IEMs have hit :)
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@ustinj Yea, multi-BAs are more likely to be "all-rounders". Also, you won't get that unpopular driver flex :)
Pros: Balanced sound top to bottom, comfortable, easily driven by my DAP
Cons: Price, miss the impact of dynamic driver bass
64 Audio U12t

1. Disclaimer: I am not an employee of 64Audio. A generous friend allowed me to borrow these for a week so I could hear what they’re about.

2. Introduction: Like many in just about any hobby, I suffer with occasional bouts of upgradeitis. It’s an expensive affliction that renders a person dissatisfied with what he has and in search of something better. As we all know, often what you find is different, not better, and another case of upgraditis is looming on the horizon.

3. Design: The 64Audio U12t is a universal IEM. It has twelve balanced armature drivers: 1 tia high, 1 high-mid, six mid-range and four low frequency drivers. “tia” stands for “tubeless in-ear audio”. Rather than regurgitate information from 64Audio’s website, I’ll provide this: https://www.64audio.com/technology/tia. The other engineering feat incorporated in the U12t (and other 64Audio IEMs) is the APEX module which vents pressure inside your ear to lessen listening fatigue caused by big pressure pulses against your ear drum. The U12t has a triangular-ish case that nestled well in my ear as well as 2-pin connectors.

4. Packaging: Since I borrowed these I didn’t receive the 64Audio packaging, sorry.

5. What’s in the box? See above, sorry again.

6. RTFM: Oops, no manual with borrowed IEMs, either.
7. Physicals:
7.1. Connector: The U12t uses a 2-pin connector at the ear phone. I prefer MMCX connectors, but who am I to judge?
7.2. Cable: These borrowed U12ts had an aftermarket cable.
7.3. Cable connector: Said aftermarket cable had a balanced 2.5mm TRRS plug.
7.4. Tips: I had quite the odyssey finding the right tips for these. I haven’t had the best luck with foam tips. My default starting place is Spiral Dot mediums. I like them for their wide bores which leave the sound pipes of the Campfire Audio IEMs I have wide open and unrestricted. The Spiral Dots didn’t hold the U12ts in my ears securely. I tried some RHA, some Final Audio E and a couple sizes of Comply Isolation. The best fit came with the Spin Fit 240 dual flange silicone tips. I wish Spin Fit would make a set of dual flange tips with a 4mm or 4.5mm bore (the whole length of the bore, not just the part that slips over the IEM sound pipe). The Spin Fits provided a good seal and good isolation.

8. Fit, Comfort, Isolation: I like the non-funky triangle shape of the U12t shell. It fit inside my pinnae nicely without sticking out, without irritating any part of my outer ear, without drooping and causing problems with the seal. The Spin Fit tips, as said above, provided support for the ear pieces and a good seal. Isolation was equal of my other IEMs. All that said, these, in my one week of experience, are not suitable for gym use. They are sort of heavy and even with the Spin Fits moved around and needed frequent reseating when I was walking around the house doing stuff. And, if I ever decide these are the IEMs for me, I’d either spring for the A12t (the custom version) or get a pair of custom sleeves made to be sure they didn’t slip around while I wore them.

9. What I Listened to: I used my AK70 Mk II exclusively while I had the U12t.

10. Soundstage: Sound staging is not a top priority for me, but here are my observations. The U12t were able to project the sound stage a little outside my head, say to the outside of my ears. They were able to reproduce some weird “up and down” effects on songs like Riverside’s “Egoist Hedonist”. There are some sounds that bounce up and down in either your left or right ear and the U12t captured that and allowed me to hear it for the first time. One song that I really hear front-to-back layering is “Dirty Feeling” by Bob Schneider. At the beginning of that song, Bob’s voice is a tiny nugget of sound right behind and centered between your eyes. Weirdly, his guitar is immediately behind his voice. I get a little frustrated listening to the soundstage of an orchestra with headphones, so I actually try not to. My problem is concentrated sounds, like the basses, come from just a single point, instead of spreading out a bit, and that’s unnatural.

11. Highs: Treble from the U12t is sweet and very clean. I never heard any sibilance or breaking up. Simple sounds like triangles and bells are, pardon, clear as a bell and pure. I think maybe high strings could benefit from some more bite than I heard from the U12ts, though. The pure-sounding violin in Arvo Part’s “Tabula Rasa” was aching, but sometimes Stravinsky sounded polite.

12. Mids: If your recording of choice is well done, midrange from the U12t is glorious. An example of bad sound from the U12t is ‘80s rock, in my case “Don’t Tell Me You Love Me” by Night Ranger. Congested, compressed dynamics, no fire from the guitars or vocals. Contrast that with Stevie Ray Vaughn’s “Crossfire” or Carlos Santana’s “Song of the Wind”. The U12ts conveyed the sounds of the lead guitars beautifully. Piano is fully rendered, if it’s in the recording you can hear the sound board (I think my example is a John Boswell recording, but I’m not sure).

13. Lows: I was initially frustrated by the bass, more about that soon. Finding the right tips helped enormously. Bass goes quite deep. I don’t listen to EDM or electronica, but the foundation was quite satisfying for the large-scale classical, rock, metal, et cetera I do listen to. What I missed occasionally was the punch of a dynamic driver like my Lyra II or new Atlas have. I’m still getting used to the Atlas, but one thing the U12t bring to the table is utter coherence between bass and midrange. No disconnection, no bleeding over or swamping. There is detail, too. While I’m typing, I’m listening to Arvo Part’s “Tabula Rasa” and can hear the bows on the bass’ strings: the basses are not just an amorphous rumble, they are bowed string instruments. Same with left-hand notes in the piano. If the keys are hit hard, you can hear the strings get “sloppy” as the vibrate hard and excite the sound board.

14. Gestalt, Zeitgeist, Fahrvergnugen (and other German words meaning “the whole enchilada”): What I couldn’t do: compare the effects of the two APEX modules. I used the module installed in the ear pieces, and I don’t even know which one it is. I did notice that I didn’t get any “popping” as I fiddled with the insertion trying to get that perfectly balanced seal.

One thing that surprised me: how volume-dependent the U12t is. I spent a lot of time listening to these at my preferred volume; that is to say, pretty quiet. I was frustrated by bass that sounded shelved down- it was there and deep, but it was much quieter than that rest of the frequency spectrum. One night I finally bumped the volume up, just a bit (from 70 to 80 on a scale of 120) and the clouds parted, puppies started frolicking and unicorns began to dance. Suddenly the bass was a forceful presence underpinning everything. As I described above: deep and rumbling with good detail retrieval and presentation. This experience made me wonder: what would these be like with an amp? Not to make them obnoxiously loud, but to increase available current and headroom. Unfortunately, I don’t have a portable amp and none of my desktops have a 2.5mm TRRS jack. Oh well.

My favorite aspects of the U12t sound are the cohesiveness and smooth, non-fatiguing nature of the presentation. All twelve drivers work together seamlessly to my ears. One morning I had them in for nearly five continuous hours (that is a personal record for me). I never wanted to turn the volume down, I never got sick of the sound, I didn’t want to take them out and turn my DAP off when it was time to move on to something else for the rest of the day. That, to me, is remarkable.

15. Conclusion: I am so glad my friend allowed me the opportunity to hear the 64Audio U12t for longer than a few minutes at a show or dealer. I’ll be sad to have to return them. There are reasons I didn’t give these IEMs five stars: I miss the punch of dynamic driver bass, the treble can sound a bit polite at times, and I haven’t heard some IEMs I am interested in and might want to rate higher. Make no mistake, though, I really liked these. I can’t afford a pair of my own at this time, but I may well start saving for a pair. Of course, with as much as I like the bass of the U12t, I also find the bass of the Campfire Audio Atlas addicting. I wonder what the trio sounds like…? TBC?
Pros: Excellent bass response, fantastic mid-range detail, sparkling and extended highs
Cons: A bit heavy.
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On of the best IEM's I've ever used

A Review On: 64Audio U12t
Review Topics:
About Me
About the product/expectations
Provided free of charge during Head-Fi.org Tour
Normal Retail Price: $1999.00
Pros: Excellent bass response, fantastic mid-range detail, sparkling and extended highs
Cons: A bit heavy.

About Me
To get started, let me tell you a little about myself.
I’m a gigging musician (lead guitar/backup vocals), an audio forensic analyst, a novice sound engineer, and an avid music lover with a wide taste in music. Being an audio forensic analyst is a plus I find when reviewing audio products simple because I know what bad audio sounds like and usually know how to correct it. My experience allows me to be familiar with the limitations of my own ears and the equipment I’m using.
For the consumers, my perspective for all my IEM reviews will be based on these things. I won’t sugar coat things or make things sound better than they are. I’m just like you and I want good value for the money I pay for any product.

To the manufacturers, I’ll always give you an option to respond to any concerns such as quality that I have during my review. I’ll contact you directly and will do so before my review is published. I want to provide an honest and tangible review for your prospective customers without being unfair to you as a manufacturer.
I’ll always be fair and my review will be based on my perspective and my experience.
Now on to the important stuff.

About the product/expectations
I received the U12t on a tour here at Head-Fi.org. The tour was courtesy of 64Audio and organized by Barra.

I am a founding member and the lead guitarist for the hard rock band Rīvul. I'm an endorsed artist for InEarz and currently my on stage performance and practice IEM's are a custom Euphoria.

My trial of these wasn't to replace or eliminate any of my current lineup of IEM's, but possibly to complement my collection.

The build quality of the U12t is outstanding, very much in the TOTL realm. The metal casing of these makes the monitors feel very sturdy, but just a bit heavy in my ear.

The 64Audio stock cable is really good. I compared the current stock cable to an older 64Audio stock cable that I have and the newer ones are actually much better. So there has definitely been some improvements. Since I also had the Trio in my tour kit, I swapped with the premium cable provided with the Trio for this review because I found the sound stage to be better with slightly better clarity. I definitely recommend using the stock cable for a while and then upgrading to a more premium cable.

I found the form factor and size of the U12t to be a very good fit for my ears. But I recently purchased a 64Audio U10 and found the design to fit my ear better than the new design. However, I had absolutely no issues with wearing them for hours with little to no wearing fatigue.

The sound of these are definitely in the TOTL realm and probably in the end game realm for a lot of people. I found I preferred the m20 module versus the m15 modules and so my review is from this perspective.

The clarity was amazing to say the least. The low end was tight with a very natural if not sometimes quick decay. The mids felt rich, but also sounded like they sat just slightly behind the lows and highs. Not a V shape signature but just a very slight U shape. Compared to the Trio, the U12t is definitely more neutral sounding.

Source didn't matter much to the U12t, in contrast to the Trio, which seemed almost finicky and starving for a better source. So the U12t should work for a wide range of people and a wide range of sources. Up to this review, I've never used Apex or Adel tech in an IEM so this was new to me. I did however find that it works well, I found myself listening at much lower volumes with the same fullness in sound. But I suppose I'm too used to a specific volume, because I typically listened during this trial at just a hair under my usual volumes.

Compared to UE900s there was no doubt that the U12t had more clarity, more separation, and better soundstage. The U12t lows were tighter, and extended slightly lower into the sub-bass region. The mids were very comparable with the U12t just edging out the UE900s in clarity. The highs of course though is where the U12t basically put the UE900s down for the count. The TIA high/high-mid drivers in the U12t are really something. Never sibilant, never harsh, pretty much perfectly tuned to provide the needed sparkle and perfectly complement the lows and mids.

In comparison with the Trio, the U12t is definitely more neutral, but not as neutral sounding as the U10. For critical listening with a bit of excitement, the U12t wins in these 3.

In comparison with U10, the U12t is a richer sounding IEM. The U10 is very good and to my ears very neutral sounding across the board. The U10 is far from boring, but the U12t is much more exciting. The the lows of the U12t are deeper, fuller and there's more attack. The mids are just a bit richer, but again it's the high's that really make the U12t shine. There's something to be said for these TIA drivers.

I used the U12t as a stage monitor during part of a practice session with my band and found there was too much clarity, LOL. I realized my playing technique as well as our other guitarist's technique and both of our tones needed improvement. Simply put, I heard some things that had to be corrected. I switched back to my InEarz Euphoria after the changes and was amazed at the difference the changes made. For critical listening, even on stage or studio, the U12t would work well, but the overall brightness in the high end, for me didn't do it. In a 4 hour show, clarity is very important but so is ear fatigue, with that being said... In my setup I'm not sure I could use the U12t for stage monitors without EQing them. However one could argue that it's better to have those highs and pull them back than not have them at all and try to boost.

I would describe the U12t sound quality to be one of the best IEM's I've ever used. Near perfection. But understand what you're going to use them for.

Isolation and fit was very good, not as good as a custom but definitely on par with most mid to high end universal IEM's. I would have liked to try these with a MAM if it's compatible or a full plug just to see the difference in the isolation and overall sound.

I think at the price point of $2000, the U12t would be out of reach for a lot of the people that I know. But for those that take their music or craft serious, it's probably a very worthwhile investment. I think for me that a custom A12t would be more to my liking due to the weight of the U12t. So bottom line are they worth the current asking price... yes. If you can afford them, then you won't be dissatisfied with your purchase. But it amazes me that these TOTL IEM's keep pushing the envelope of what the best really is.

Good job 64Audio.
Great review, sounds like the Tia driver is exactly what the A12 needed!
Thx for a straight to the point review and sharing your experience with the u12t.
Nice reading! :) As for the weight, I would say it feels heavy compared to the previous 64 audio' line because of plastic shells but comparing to other TOTL IEMs, the weight is about average :)