Great review, thanks for all the effort.  Outstanding job of writing.  One thing that mystifies me that we will never know is would 64 Ears have designed and voiced the U12 and A12 the way they did if it weren't for the availability of the ADEL module.  Seems like you found a synergism, which is what I get from my A12s, that will never let us know which is the chicken and which it the egg.  I do agree totally that the A12 is nowhere's near as nice without the ADEL (just take it out and plug the hole and see what you get--you'll plug the module right back in place).

Superb review. As an A6 owner it is (almost) enough to make me upgrade.

Oh that long nozzle stem...SO MUCH WIN!!!!!!!
Epic review!

What a great review @twister6. Really like how you went into detail with the ADEL modules and benefits of ADEL. Sometimes it seems like other reviews only focus on the sound, but this one was very detailed from the modules, sound signature, case, cables and recommendations on type of cables that may work best depending on source. Really paints a great picture of the product for those of us interested in this product and this is perhaps my favorite review of this product so far. Great that you were able to review both the universal and custom versions. 

Great review. Thank you. 

great review, i was just wondering for the U12 if you close the MAM what effect will have on bass, also does that mean if u close the MAM completely that the adel tech then will not work to release pneumatic pressure and prevent negative effect on hearing

@hykhleif : you close MAM by turning the dial "closed", and that will have an effect like a default non-adjustable auto-module.  With auto-module, if you cover the pin hole opening, you will no longer be able to release pneumatic pressure, so it will be just like any other IEM/CIEM.

if my memory is correct i read somewhere that the automatic is like 70 closed of MAM, so i was wondering if i get the MAM and close it up to 90% what change would i hear compared to the automatic module, as I do not wnat to buy a module that will lower the bass punch. If buying the MAM will redcue the bass then simply its not for me as I like the bass of the automatic alot, so if buying the MAM will give even more bass then only would i buy the MAM

@hykhleif : as I mentioned in my review and also posted measurements of MAM adjustment in ADEL thread, adjustable module only reduces the bass.  So, it's not for you   Since you are a basshead, U8 probably more up your valley.

maybe you got me wrong the bass is fantastic on u12 and i am not asking for more, but i thought buying the MAM will not affect the bass, and add more to the sq of what i already have, I am asking because I do not waat to spend extra money only and only if bass does not get affected or gets even bigger. But by all means I am more than happy with the bass of the u12 with automatic module

Excellent review as always! However, my medical training and understanding of the human ear puts extremely strong doubt in my mind about the effectiveness of the module in preventing hearing loss. In fact I am pretty sure it does nothing to help prevent hearing loss

That said I won't derail this excellent review, do feel free to drop me a PM though if You wanna know why I say that

Also, again nothing to do with your review but just from something you mentioned in the comments, U8 is surprisingly not all that bassy, very unlike the old V8. The U12 has taken over as the bassy iem in the line up!

Incredible review! Do the Westone ear tips work well with the U series and what tips did you personally find comfortable without blocking the nozzle?

@KC33 : westone was a stretch, literally   I'm using Oriveti Primacy tips now (FLC8s uses those too).  You just gotta try different tips to see which one going to fit you better without blocking the nozzle.  I'm sure some people will prefer Comply or maybe double or triple flange tips (MEEaudio makes great multi-flange tips).

Very helpful review: but do you have a comparison between A12 and A10? There is some review telling me that A10 provides more distinct vocals but less details and smaller stage. And I'm actually choosing between them.

Ome more question, I promise barring comfort and style how does the U vs. A matchup?

@BambiV don't have A10 or U10, but they should be very close in sound to A12 where 12 has 2 more bass drivers.  Whoever wrote about less details and smaller stage really has no idea what they are talking about, it's actually funny to hear it because thanks to ADEL module and overall A10/A12 tuning the soundstage is very wide.  What people probably hear is that with less bass, the sound is a little more balanced where mids come a bit more upfront (thus more distinct vocals).  Sounds to me like you are leaning more toward A10 but held back by "less details and smaller stage" comment which is misleading.  If that is a case, definitely go for A10.

@twister6 Thanks for your reply! Yes I'm leaning more to A10, so I may go somewhere to have a test listening and make the decision finally.