What Shadow Lies Beneath the Bright Gleam – A Review of the 64Audio U12


So without further ado or preamble, how about we get into how these things sound, yes?

As I mentioned earlier, these used earphones came with the ADEL B1 Module. Since 64Audio split with Asius, thus no longer use ADEL, they’re enthusiastically promoting their competing tech, APEX. Roman Belonozhko of 64Audio kindly sent me their APEX M15 and M20 Modules for comparison. You can read that article here.

Left – APEX M20, Middle – APEX M15, Right – ADEL B1

I will say, for pure sound quality, I prefer the M15 module. By a smidgen. Most of this review was written using the B1 ADEL, so try and keep that in mind. If I gush over the B1, the M15 is even better to my ears.

The B1 Module concerned me. Everyone says it is less in the bass department than the standard S1. I like my bass, and I like my warmth, and I feared this module would take away everything I wanted from the U12. Credit Card in hand, I was ready to order the S1 Module if these didn’t please me.

And in fact when I first tried them on, they did sound terribly hollow. For a few minutes I thought I’d be placing that order. Then I started tip rolling, and realized I simply didn’t have the best seal. Once I achieved a proper fit, my jaw dropped.

The 64Audio U12 contains a dozen Balanced Armature Drivers in each ear. Four bass, four Mids, and four highs. With the ADEL B1 Module, the U12 is a true warmth monster, but not in the traditional sense. There is phenomenal air and an impossibly wide soundstage for an IEM. Articulation and detail are well above what they should be, given how liquid and relaxed the presentation is. Tonality and naturalness surpass in-ear technology entirely. They sound more like full-size cans than any IEM I’ve heard.

Treble is handled differently than other equipment. It’s subdued in volume against the rest of the mix. Although extension is one of the best. It’s all there, no roll off. It’s merely hushed. This took me a day and a half to grow accustomed to. At first it sounded very strange. Once my brain adjusted, I heard how clear and pure the highs really are. No veil clouds the details. I heard everything, illuminated under a soft immaculate light that felt utterly organic. These are the earphones you buy if you’re allergic to harsh treble and hate sibilance. However, if you demand bright, sparkly treble, look elsewhere. Check out Solar. Or if you want to go even further down that road, the Kaiser Encore.

If there’s one thing I know in my audio gear, it would be vocals done right. Between the IM03, Angie, Solar, the HD600 and the LCD-2, I feel like an expert. Outside of full-size headphones, I’ve never heard the mid-range sound this lifelike, or this effortless. Again, these things just don’t seem like IEMs. I’m not saying they are as good as the HD600, but goddamnit they are closer than they have any right to be. The U12 just sounds taller and wider and less strained than other IEMs. They reproduce that natural quality which makes you NEVER want to stop listening. Which you can do, since they never cause fatigue.

That mid-range is lush! Silky, creamy, and warm. Yet frightfully clear. Once your ears adjust to the sonic profile, you grasp just how transparent, vivid, and detailed the sound is. The veil you may perceive at the beginning does not exist, and you long for nothing but this signature for the rest of your days.

If you’ve seen a frequency graph for these, then it should come as no surprise the bass stands front and center, so to speak. It’s raised above the rest of the spectrum. I won’t say the U12 is a basshead monitor, especially with the B1 or M15 Modules. It is too well balanced for that. Not neutral. God no! But masterfully sculpted. I love bass, a lot, but I have been known to go for a completely flat response to get away from IEMs that muffle or bury the vocals. I was happier with the Klipsch X7 over the much bassier R6 for that very reason. Then I discovered the IM03 and learned I could have my cake and eat it too. I’ve been chasing that signature ever sense.

64Audio knew what they had on their hands when they chose to emphasize the bass like this. It’s GLORIOUSLY layered, with sub-frequency extension that goes DEEP and rumbles where you can feel it more than hear it. The character and texture allows every bass instrument to shine in their own unique way. I’m inspired by how diverse every song’s sub-range sounds with the U12. Excluding only the LCD-2.2f, this is the best low-end I’ve ever heard.

ADEL’s B1 Module isolates better that I feared. Not as well as a traditional IEM, but if you have music playing, you won’t hear people talking, or moderate environmental chaos. It takes a good degree of horror to bleed in. The S1 Module is meant to isolate better, and I can attest to how well the APEX M20 does it. Again, see my comparisons.

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About Author

Pinky is an artsy twat. Illustration, graphic design, writing. Yet music escapes him, and always has. He builds his own cables, and likes to explore the craftsmanship of others. He's a stabby one, also. At the first hint of annoyance, out comes the blade. I say he's compensating for something... in a big bad way. If we all try really hard as a collective, maybe we can have him put down.


  1. Albert on

    so uhh… I googled pinky powers looking for this review… and the first result was pornhub……..

  2. matique on

    Hey pinky,

    Just wondering, what’s the cable with the right angle 2pin connecter in your last photo?

    • Pinky Powers on

      That’s the ALO Audio Reference8.

  3. Lord Sinister on

    Hello Pinky,

    Outstanding review, as always. Out of curiosity, have you heard the LZ A4 and if so, how does the bass regions compare to that of the U12? Have you tried the U18 as well?


    • Pinky Powers on

      I have not heard the A4, sorry.

      There are two hybrids I’m currently reviewing: The Unique Melody Merlin, and Campfire Audio Dorado.

      Dorado is, thus far, the only IEM I’ve heard that beats the U12 for lows. U12 beats it in everything else, but damn, I really like that Dorado bass.

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