Introduction:
Okay here we go!
The 64 Audio U12Ts are my favorite IEMs to date. I'm not afraid to say it. I wanted to mention my love for them at the start for fear as I'm writing this of encouraging people to go out there and spend... $2,000 on an in-ear monitor, which by its very nature is an audio category inherently limited by form and function. For the sake of full disclosure, I was able to purchase these second-hand for around $1300, which may potentially skew my perception of their "value." That being said, I'm not going to get too paternalistic here. If you have the means and you want a phenomenal IEM, I'd highly recommend this one. Alright let's get into it.
Cable and Accessories:
I came very close to docking these IEMs a half-star based on packaging and accessories alone. Ultimately, sound triumphs over all, but the packaging and accessories here are straight up bad.
I guess let's start with the case. Not only is it bulky and difficult to handle, but it also barely even fits the iems with a cable. Further, the inside of the case is made out of hard plastic, which is not really the material I want my $2k IEMs bouncing off of every time they're in there. Just not good. Honestly, I'd rather use a $3 case off Amazon.
Moving on to the stock cable, I'm just flabbergasted that this is what they included in the box. I had heard it was bad, but I didn't know it would be completely unusable. God-awful memory wire, bad microphonics, discomfort, and tangling. It's an absolute mess. I can’t imagine that even those using this IEM as a stage monitor would find this cable serviceable. It’s a bit inexcusable at this point. I think 64 Audio know this though as it seems they are providing some better accessories in their newer models such as the U18s. Anyway, if you're going to get these, also get yourself a $15 Tripowin cable, or a $2000 fancy one if you're into that kind of thing. Sorry for the rant, just had to get that off my chest.
Build Quality and Driver Configuration:
Thankfully, the actual build quality of the IEM’s shells feels excellent. They are light, but very solid in the hand with a smooth aluminum finish that feels premium. I've also noticed from general use (and sometimes misuse) that they are pretty scratch and dent resistant. I’m a fan of the understated look since I’m not into flashy IEM shells. Though I am aware that some may find it a little boring. In terms of comfort, the U12Ts fit me better than any IEM I've tried in the past. Of course, this is a super subjective impression, but I thought it was worth mentioning. I can wear these forever and I’ve fallen asleep multiple times with them in.
As for the driver configuration, the U12Ts have 12 balanced armature drivers on each side. This includes 1 tia high, 1 high-mid, 6 mid, 4 low. That's a ton by any metric. While I'm well aware that driver count is not necessarily indicative of better sound quality, the U12Ts drivers are expertly integrated, surprisingly coherent, and the benefits to resolution are immediately apparent. On that note, let's get into how they actually sound.
Sound:
All my listening was done with the M15 APEX module since I do not have the other modules on hand. In terms of critical listening, I primarily listened to them off my Cayin N6ii with the E01 motherboard. I also frequently used them for gaming and took them out and about using an iPhone dongle. Regardless of what I plugged them into, the U12Ts sounded great.
Overall Sound Impressions and Frequency Response: The U12Ts present with a decidedly U-shaped frequency response. They have a strong subbass and upper treble emphasis, as well as a warm-neutral midrange with a slight, tasteful bump in the lower mids that add a nice hint of body and fullness to the sound. The upper mids are a little pulled back, which recedes some vocals in that range, but it’s in no way egregious and imparts some (perhaps slightly manufactured) staging depth.
Just to reveal my biases, this tuning very much aligns with my preferences. There’s a smoothness and fluidity apparent throughout all frequency ranges, without sounding muted or blunted in any way. In fact, the U12Ts pack a surprising amount of punch and impact, which for some reason I was not expecting. Overall, they’re just a very musical IEM, combining an easygoing tuning with excellent technicalities and dynamic range. Let’s delve a little further into the weeds.
Bass: The first time I put these things in my ears I actually felt they were almost too bassy. As my ears adjusted, the beauty of the U12Ts bass response made itself readily apparent. This is not just excellent bass “for a balanced armature driver.” This is just plain excellent bass full-stop. It actually possesses many of the qualities of a dynamic driver, with a lengthier decay, fantastic extension, and really good textural nuance. Yet it still maintains some of that desirable agility that BA bass can have. It even hits pretty damn hard when called upon. I was very pleasantly surprised with how satisfying certain bass focused tracks could be.
In general, the added subbass presence here contributed nicely to a lot of the music I listen to – jazz, funk, neo-soul, Snarky Puppy (<3), R&B, EDM, French-house, some rock, a little classical (mostly string quartets). It achieved really good solidity and body while demonstrating exceptional control. I was also incredibly pleased with the bass detail and clarity. No matter what genre of music I was listening to, fast bass passages were expertly navigated and came through with transparency even during the most hectic musical moments. Some high-quality DDs can provide a little better density and deeper feeling rumbles, but I can’t stress enough how fantastic this bass response is overall.
9.5/10
Mids: The mids on the U12Ts are excellent. There’s a very slight lower mid emphasis that adds just the right amount of warmth and richness without ever sacrificing clarity. In fact, the resolution is absolutely insane, and remains truly impressive after over a month of daily use. There’s a smooth, but pristine quality to everything. It’s warm, but never smeared, congested or thick - just laid back and ultra-clean. I absolutely love this tuning, as it permits for a very easygoing listening experience with zero harshness, grain, or haze. This also makes the U12Ts pretty damn forgiving, even on poorly recorded tracks.
The midrange timbre of the U12Ts is highly realistic and emotive. Obviously, the excellent technical aspects contribute greatly to the ability to present an accurate rendition of instruments and vocals in this range. However, there’s also a nice roundedness to everything that provides the mids with an extra lifelike quality. Vocals sound very natural with added depth and richness; guitars sound plucky and beautifully reverby; and brass instruments sound breathy, punchy and lively. Though the U12Ts do not display the same textural qualities that were apparent with the Unique Melody MEST (mk1), it does have a more agreeable tuning in this range overall than the MEST, and presents with a bit more detail, but more on comparisons later.
Now, it’s important to note that there are some characteristics within this range that may not entirely align with everyone’s preferences. Vocals are not quite as present and feel a bit more pulled back within the mix when compared with other sets. There’s also a pretty noticeable dip in the mid-range from 3-4k, which takes some of the spice off the leading edge of percussive hits. While this generally lends favorably to the fatigue-free listening experience, I sometimes like a bit of spice here and there.. Overall though, phenomenal detail retrieval plus extremely natural timbre equals a top-tier midrange presentation.
9/10
Treble: All this and I haven’t even gotten to my favorite part of the U12Ts frequency response – the treble. I did warn you that this would be a bit of a shill review, but I just can’t help but love the treble response here. It’s very unique actually. It’s got superb nuance and distinction from the other frequency ranges and comes off as highly refined. Not only that, but there’s a ton of air above 10k which just gives everything in the range a sparkly wonderful burst of clarity (pretty sure that’s the technical term for it) no matter what you’re listening to. The whole range sounds undeniably smooth and agreeable, while also being well-extended without any noticeable roll off.
The detail in this range is just amazingly good. In fact, it’s probably the most detailed treble response I’ve heard to date on an IEM. Everything feels expertly delineated and nuanced. Cymbal strikes exhibit a noticeable variety based on where exactly the drummer is actually making impact; and tiny blips and upper frequency noises come through with fantastic presence and vibrancy. There’s also a bit of extra decay and reverb that’s just so musical and timbrally satisfying. Now, would I call it perfectly "natural" or "neutral"? Probably not. There’s absolutely some coloration going on here, but it’s all for the better. On top of the wonderful tuning characteristics, the treble has real body and fullness - none of the wispiness that one might expect out of a warmer, smoother overall signature.
All in all, the U12Ts treble manages to be thoroughly non-offensive, while also being beautifully airy and ultra-clean. Really best in class in my opinion.
10/10
Soundstage and Imaging: Speaking of best in class, the soundstage and imaging here is also done at a top-tier level. Regarding the soundstage, the U12Ts have a special dispersed, open feeling presentation. This is accomplished with fantastic width and depth, in conjunction with super precise instrument placement. The imaging here never feels like it’s jumping around. If something is moving from left to right, you can hear every single moment along that directional spectrum. When blended with the U12Ts openness, this really becomes more similar to a headphone-like presentation than that of an IEM. This character is helped along by the phenomenal detail retrieval and ability to vividly display all the tonal elements of each individual note.
I can’t stress enough how fun and musical this staging presentation ends up being. It’s really one of a kind and in many ways could be considered the crowning achievement of this IEM. The one thing I’ll say is that there’s not as much of a “3D” effect that some IEMs can portray, since there’s a slight lack of textural feel. Also, it can get quite diffuse feeling and, in combination with the slightly pulled back mids, the U12Ts can come off not as intimate as some may like. Overall though, in terms of pure enjoyment factor, the staging and imaging here are substantially better than pretty much everything I’ve heard in the IEM space.
9.5/10
Comparisons:
U12T vs. UM MEST (mk1): This is a close one. I absolutely loved the MEST (mk1) and still think they offer a very unique, satisfying, highly textural sound experience that is hard to beat – particularly for the price. That said, I do prefer the U12Ts by a decent margin. Though the U12Ts don’t have the same textural feel throughout all frequency ranges that the MEST has, the U12T’s tuning is a bit more agreeable to my ears. The MEST (mk1) are pretty V shaped with a forward vocal presentation, and I’d say a bit more treble focus than the U12T. Whereas the U12T have a smoother, more laid-back U signature with emphasis on opposite ends of the frequency spectrum. I find that the U12Ts tuning presents with a bit more coherence and ease while not sacrificing any technical aspects, whereas the MEST sometimes feels like it's trying hard to impress.
To be more specific, though the MEST (mk1) have slightly more bass texture than the U12T, the added subbass presence on the U12T was more satisfying for me overall, and I felt that the agility and technical nuance of the U12T’s bass was more than enough to compete with the MEST’s fantastic bass response. As far as the midrange, I do prefer the tuning of the U12T as it just feels more linear and even overall, with a nice bit of added warmth that I found was a little lacking on the MEST. I also felt that the U12Ts provided a noticeable jump in detail retrieval when compared with the MEST, though the MEST is still a high-level technical performer. Treble is where the U12Ts kind of separate themselves from the MEST for me. I just love how smooth and airy it is, whereas the MEST kind of presents treble in a more exaggerated up-front manner. Not to say the MEST is harsh by any means, it just feels slightly less refined than the U12Ts.
The one thing that the MEST has over the U12T is a bit more of a “3D” staging effect due to a more textural overall presentation. This aspect of the MEST is still very unique for me and provides a tactility that is super addicting. My main issue with the MEST, however, was how fit dependent it was, which made daily use a bit more finnicky than I wanted it to be.
Overall, I do prefer the tuning and the technicalities of the U12Ts, but it’s really not by a lot. The MEST is still a fantastic IEM and considering that it can often be found for a considerably cheaper price than the U12Ts, it’s a pretty close call. However, in my view, the U12Ts win this head-to-head when all is said and done.
U12T vs. Sony IER M9: This was not as much of a contest in my view. While these two IEMs share some similarities in their presentation and tuning, the M9s do everything just a little worse than the U12Ts. The bass on the M9s is a little bloatier, more mid-bass focused and less textured than the U12Ts, though it’s still excellent as far as BA bass performers go. The mids between the two are a little closer, as the M9 has great timbre and tonal balance. However, the U12Ts just have an extra bit of dynamic punch and musicality in the midrange that is a little lacking on the M9s. The U12Ts also do treble noticeably better than the M9s, with the M9s coming off as a bit darker overall, with less clarity and air. This is saying something as the M9s are by no means a dark IEM and have very good extension, it’s just no match for the U12Ts top-end transparency and refinement. The staging is where the gap between the two IEMs gets a little wider, both literally and figuratively. The M9s sound a bit claustrophobic when compared with the U12Ts, despite their otherwise great imaging and separation capabilities. The U12Ts are far more open and spacious feeling, with much better depth characteristics. I'd take the U12Ts every time, but the M9s still offer great price to performance.
U12Ts vs. ThieAudio Clairvoyance: The Clairs are quite a nice IEM, presenting with an agreeable tuning and great technical abilities for the $700 price tag. That being said, they don’t really compete with the U12Ts, which is somewhat to be expected. Though it’s maybe an unfair comparison, I did want to say that even though the Clairs have a dynamic driver for the bass, I actually much preferred the bass response on the U12Ts. The amount of extra detail and texture you get from an upright bass pluck on the U12Ts is on a much higher level from the Clairs, which sounded a bit one note in comparison. The mids on the U12Ts had a much nicer timbre and that nice added low-mid body that was not as present on the Clairs, though I will say that the Clairs have a really nice evenness through the midrange that just felt right with certain vocals. The treble is no contest really. I did not love the treble on the Clairs at the end of the day as it felt a little bit wimpy and grainy, despite being pretty detailed. However, I did find that the soundstage of the Clairs compared favorably with the U12Ts.
Not surprisingly, the U12Ts are a noticeable upgrade from the Clairs, and in this case if you’re deciding between the two, I’d save up some money and try to get a good deal on the U12Ts if you can. They’re just so damn good.