Review: 64 Audio ADEL U12 – Smooth Criminal

This is a guest review by Berkhan and it’s his first review in English. The Adel U12 in universal version is a loaner unit. Welcome Berkhan!


I’ve been an audio enthusiast for several years. Especially in the last 2 years, I’ve climbed the steps in terms of in ear monitors.

Thanks to the great audio community in Turkey, I’ve also been able to experience some more top tier IEM’s in recent months, and Adel U12 is one of them. So I would like to thank my friend who sent me this great IEM for testing.

This will be my first comprehensive review written in a foreign language, so thanks for that Lieven! Hopefully I can keep up to contribute to this community in a good way.


We also know them as “1964 Ears”, who are quite renowned as Custom IEM makers, and recently they’ve become more into the Universal IEM market, like some other CIEM makers out there.

“64 Audio was started by Vitaliy Belonozhko, a sound engineer who has been working with musicians and production companies in the Northwest for more than a decade. Not long into his career he discovered the advantages of IEMs over traditional floor “wedges”. After trying out a few brands it was apparent that a better and a more affordable solution to in-ear monitoring was needed.”

They’re located in US, and they became more of a corporate company in recent years, rather than a small workshop that produces small amount of CIEM’s. They got several technicians, engineers and designers in their crew. They pretty much know what they’re doing I should say.

Headfonia reviewed the 1964 V6S several months ago but this is only the second time we feature 64 Audio.


So 64 Audio recently introduced a new technologic achievement called “ADEL”.

This is intended to avoid hear loss as much as possible as it’s something linked to in-ear monitors for some years now, especially with high volume levels. Here is the thing: When you listen to music with earphones, they constantly produce air pressure, which causes your natural eardrums to move a lot. It also causes fatigue.


To avoid this, they placed a secondary eardrum inside the IEM’s.  This “Adel Auto Module”, absorbs pressure in the ear canal, which results in safer listening sessions and the sound is delivered to your ear drum in a more natural way. What they also claim is the improvement of the stereo image and better sound quality, which I’m going to talk about shortly.

Both A and U series IEM’s come with this module, and it’s user replaceable. This innovation is very intriguing in my opinion. Considering the fact that many IEM’s cause ear fatigue and they’re often aggressive and harsh to your ears, even some TOTL ones. This is a good effort to make the sound smoother and comfortable. Personally, I prefer a smooth sound as well.


The package is quite small, simple and minimalistic, but that’s not a problem for me. Flashy boxes and introductions are not what we’re looking for, it’s the sound.

The package includes a storage case (which is quite impressive), 3 pairs of comply ear tips, dehumidifier, a shirt clip and of course a cleaning tool. There’s also a 64 Audio sticker to mention. Next to that, the package contains several informational texts, safety warnings and some info about ADEL Technology.


I want to say some good things about the case here: it’s very well designed, and it differentiates itself from others, by including small rooms to store all your accessories with the IEM’s. It also has a built-in dehumidifier to keep the IEM’s “dry”.

When I travel around or go out with my IEM’s, I want to carry my cleaning tool with them for instance but when you put it into the case, it goes all over the place and sometimes when you open the case to get your IEM’s, it can fall and you can lose it. So I should congratulate them for producing this kind of case in which you can safely carry all the accessories.

What it also has is a wrap and lock mechanism to keep the cable neatly wound, which is also a well thought feature. To wrap up the packaging, it has everything you need in a compact box, and the storage case is excellent. I’m impressed, but I would have prefered some more tips though.


I have to say, for the 1600$ price tag, build quality and design should have been better. It leaves some to desire, honestly. The plain gloss black finish looks somewhat boring, the markings on the sides look good but that’s about it. It looks and feels a little cheap and plasticky.

Of course they’re not cheap but the design itself makes them to look cheap. I don’t think they can break or crack in any way whatsoever but they don’t show off a build quality like the newest Noble K10 or JH IEM’s etc. I cannot get the “premium” sense with these. On K10’s, you can clearly feel the build quality when you get them onto your hands, aluminum finish even makes your ears cold a little bit at first insert. On JH Universals, there are carbon face plates and aluminum bores, even the earlier versions (before the new FMJ line) had the kevlar casing inside. On FitEar TOGO 334’s, which I recently had a chance to test, there’s the perfectly finished acrylic shell, titanium bores and build-to-last cable.


So the build quality gives me a little disappointment, especially considering the price. I’m not a fan of ultra impressing designs and I’m more of a simplistic guy, so I don’t have a problem about the looks. But one can definitely say that there are some IEM’s that make you think they are perfectly built like a tank, and these clearly don’t give you that feeling. They don’t stand out like some others. In short, these fall behind the competition regarding build quality.

It continues after the click here or below, on Page 2

4/5 - (41 votes)

A keen audiophile and hobby photographer, Berkhan is after absolute perfection. Whether it is a full-frame camera or a custom in-ear, his standpoint persists. He tries to keep his photography enthusiasm at the same level as audio. Sometimes photography wins, sometimes his love for music takes over and he puts that camera aside. Simplistic expressions of sound in his reviews are the way to go for him. He enjoys a fine single malt along with his favourite Jazz recordings.


  • Reply July 21, 2016


    Good and detailed review,was interested in this iem but warm and technicaly behind the rest of the pack no matter how musical and smooth is a no.No point in testing ZX2 in stock form,the sound is noticeably warm,veiled and treble is lacking detail despite musical signature.The only way to seriously test ZX2 is with TRRS plug and disabling sound adjustment in the all app menu.Have yet to find such review with other high end daps although admittedly not fault of the reviewers,sony being sony again.

    • Reply July 21, 2016


      It’s simply impossible to get sony review samples :/

      • Reply July 21, 2016


        I understand that,Sony is a big company and a bit arrogant like apple,you need us we don’t need you kind of mentality which is a shame because ZX2 is a wonderful sounding device with the longest battery in all high end daps.I prefer my ZX2 with TRRS and SE846 than all my other daps,dacs including chord mojo.

        • Reply July 21, 2016


          Does TRRS really make such a difference? ZX2 has been in my possesion over a year and I’ve never tested with a TRRS plug. Btw, I know how to disable sound adjustment app. It gives the pure sound of the device but sometimes I need some EQ.

  • Reply July 21, 2016


    Yes,once you do the rest like burn in of 200h so capacitors to settle in,use the TRRS plug which gives a cleaner/blacker backround,increases treble sharpness and instrument separation and disable sound enhancement in all apps menu(no clear bass or eq sorry)then Sony begins sounding like the $1200 device it is.This is the most accurate review of ZX2 by Whitigir of headfi and i agree since i have both of units tested.

  • Reply July 21, 2016


    TRRS provides cleaner/blacker backround,increases treble detail,instrument separation and dynamics as long as you disable sound adjustment(no clear bass,or eq sorry) then ZX2 sounds like a $1200 device.Most accurate review yet

    • Reply July 22, 2016


      Thanks for the info. I’ll check it out.

  • Reply July 22, 2016

    Ahmet Er

    Thanks for the review Berkhan my friend.
    U12; Warm and soft with a signature.
    There are high frequency roll-off and elongation lack.
    For lovers of soft and warm presentation, U12 is a good option.

    • Reply July 22, 2016


      Thank you my friend. I hope you enjoyed it.

  • Reply July 31, 2016

    Richard Fitzwell

    My A12s are great and I have been using them for both listening to music and while I play. I credit the Adel modules by Asius Technologies, who manufactured the component. I heard of them before and checked out the musicians who they deal with – top notch.

  • Reply December 1, 2017


    Great review, thank you.
    Could you please review 64 Audio U10 as well if possible?
    thank you!

  • Reply August 31, 2020


    I owned two sets of 64 Audio U12 their tremble and mid-range are different. So I assume that there were actually two versions/generations of U12. V1 is ADEL era, with “ADEL” printed on one faceplate, and “64 Audio” printed on the other faceplate. V2 is doesn’t have “ADEL” on the faceplate, both faceplates printed with “64 Audio”

    V2’s highs are more intimate, direct, more sparkles. V1’s highs are more veiled, distant, analog, rounded off. V1’s mids and lows have more resonance and more beefy. V2’s mids and lows are cleaner, more linear, more pleasant.

    • Reply September 11, 2020


      Thank you for sharing the info.

      It was surprising to see a comment under my first ever HFN review!

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