Review: 64 Audio ADEL U12 – Smooth Criminal

The treble area is the most problematic part. If you’ve read the review until here, you can assume that this is the least focused part of the spectrum. That’s not necessarily a flaw of course, it’s a preference. But the problem is the extension. The extension of treble is poor with the U12 compared to other IEM’s around this price range. What it also suffers from is the timbre just like the instruments in mid frequencies.

With some IEM’s, we say “quantity is low with treble, but it has a high quality and extension”. With U12, I can say both quality and quantity is weak for this price tag. Again, it’s similar compared to the HD650 and again it’s very smooth. I can understand the effort to make these IEM’s soft but the treble is a little too thick in my opinion. It shouldn’t be this way.

Cymbals don’t feel natural and you can’t get the timbre, it ends too fast and tonality is too bold. Even though I like and appreciate laid back treble, the problem lies within tonality. It can be acceptable to put some amounts of thickness with mids particularly, but with high frequencies, you need a natural extension to get a good sense of air.

TECHNICALITIES

Resolution is not super impressive. Again I say the U12 is not aimed fully at technical parts of the sound, it’s intended to be non-fatiguing and enjoyable. So it’s not a super revealing IEM, but that’s understandable.

Expectations are very important in this regard. You should not expect a resolution like Spiral SE-5 CIEM or Noble K10 with this sound signature but if you expect a fair amount of resolution given to the aim of delivering a smooth and dark sound, you’ll be very happy.

Soundstage width is really impressive. It’s much more than average compared to most IEM’s out there but I can’t say this about the depth. Stage is kinda close to you, but really wide. It gives an open feeling, even with the dark sound signature. If it had more depth, it would be more relaxed but that’s what we have. Overall, I think the soundstage is excellent thanks to the great width.

Separation and background capabilities also impress. You can identify every type of instrument in a recording, and you can say where they are at that moment. Background is pretty dark as you should expect from this price range. So basically I didn’t find any problems in these areas. Based on the signature, I should say they’ve done a very good job with this.

The level of detail is pretty much the same. It’s a success to me and even though the IEM doesn’t throw every little thing to your ears, it still gives great details when you’re concentrated to the sound.

SENSITIVITY AND SOURCES

U12 has 16 Ohms impedance, and sensitivity is 115db. As you can see, it’s easily driveable. You can use it with every type of source, and you’ll be OK with the volume every time.

It’s not a source picky IEM, which could be excpected from the sound signature. I’ve listened to the U12 with the Sony ZX2, Lotoo Paw Gold and Hifiman HM901S. The best synergy was with the Hifiman because it sounds so open and relaxed. It irons out most of the problems of the U12 and you get an amazingly nice and smooth sound, with great sense of detail and separation. The Paw Gold was also exceptional given that it has an amazing resolution, but based on synergy, the Hifiman was better. Paw Gold sounds kind of close and bassy and the combination sounds muddier compared to Hifiman. The Sony ZX2 was the worst, not just because it’s the lowest DAP in terms of SQ among the three, but it’s too dark and warm with U12.

So based on my experience, I recommend to match these IEM’s with open sounding, relaxed and a little bright source.

SOME SOUNDS COMPARISONS

Noble K10U is maybe the best IEM I’ve experienced in terms of resolution, separation and tonality. So in these areas, U12 can’t compete in a technical approach. On the other hand, even though it’s been considered somewhat a warm IEM, K10 still falls behind in terms of smoothness. I think U12 is the smoothest one I’ve listened to. K10 gives the elements of the sound somewhat “in your face”, it’s much more revealing and has a cleaner sound in the whole spectrum. U12 is the exact opposite and it has better and wider soundstage than K10.

JH Angie has been my daily IEM for a year. It shares some similarities such as the thick mids and laid back treble but the treble on the Angie has more extension and sounds more honest to me. Both aren’t technical IEM’s, they’re smooth and warm and they don’t have great resolution but the U12 is warmer and has a bit more low end. Angie has the edge to me because of high freq’s. Soundstage is similar except Angie has more depth. Tonality is similar, but U12 is thicker a little bit.

UM Maverick has much deeper bass, much more treble and it’s much more energetic. Soundstage is narrow compared to U12. It has the openness, which the U12 doesn’t have but especially mids sound thinner compared to U12. It shares the extension problem about the treble even though it’s much brighter. Maverick can tire you with long listening sessions, U12 never does that. Overall U12 is more pleasing on this comparison.

FitEar TG334 has the best mids I’ve heard, miles ahead of U12. Treble sounds similar and they both give me thick tones in that area. Extension is also not great on both of them. U12 owns TG334 in terms of bass, there’s no doubt about it. Quantity is similar but the quality of lows is mediocre on FitEar, considering the price range. Soundstage is wide with FitEar, just like the U12 except maybe U12 is a little wider. Depth is around the same.

JH Rosie has a faster bass which makes it a great metal IEM. But the problem with Rosie is it doesn’t have the rumble in any way whatsoever even if you crank up the bass from the cable. U12 gives a little more dynamic driver type of bass, Rosie doesn’t. Resolution is better with Rosie but it’s too harsh sometimes with treble and upper mids. U12 on the contrary, has miles better control, is much smoother and it’s a much more consistent IEM. Soundstage is also much better with the U12.

CONCLUSION

If you want the Sennheiser HD650 sound in a universal IEM size, the U12 is definitely for you. I liked it very much because the HD650 is one of my all time favourite headphones. I also enjoyed U12 everyday I listened and it’s been a good time listening to music with this sweet IEM.

At the same time for a 1600$ price tag, some things could be better such as build quality, resolution and especially the treble presentation.

The package, carrying case, accessories, all are satisfying and particularly the fit is great with this type of 12 driver IEM. So I think they deserve a praise concerning these things.

In the end, I can surely say that U12 gives you what the company intended, which is a pleasing, non-fatiguing, smooth and consistent experience.

It all comes down to preference in audio as you know, do you want a reference and fully technical sound? One that gives you every single detail and shows every flaw of the recording, or do you prefer a warmer, musical and thicker sound? The latter requires more attention from you to hear the details and be aware of the seperation but overall it gives you a more comfortable listening.

It’s all about answering these questions. If you say yes to the second one, you’ll be very pleased with ADEL U12.

I would like to thank Lieven again for giving the opportunity for writing a guest review for Headfonia, and again I would like to thank my friend here, for giving me the earphones for testing.

Have fun.