Received my U12 early, FedEx was lightning fast shipped wednesday afternoon arrived this morning
It has been said already but the U12 are not big for a 12 driver, roughly the same size as my former Earsonics S-EM9, only much thicker they do protrude quite a bit
Finish is very good, I was impatient to check how the angled nozzle fit my ears and lucky me it's just a perfect fit like they were built for me, my canals are just angled that way as it turns out. The U12 sit flush on the concha, fully inserted. That nozzle is much deeper than what I am used to by the way. It's just the right bore size for the JVC Spiral Dots that fit like a glove both on the U12 and in my ears (the U12 came with comply but I am not a fan of them, especially with my big ear canals I have trouble getting a seal, using L sized Spiral Dots here).
After a hour listening, very first impressions with stock cable from Onkyo DP-X1, if I had just one word : effortless.
What struck me was how quickly I forgot the U12, in fact almost right away, which is really strange as I was very intent on critical listening to grasp their sound signature and presentation of music. Very first feeling was how open they sound, which is probably why you forget you're wearing them and that's an unusual feeling for an IEM. I love the soundstage because it didn't wow me by trying to hard, it's just a very open and holographic but natural presentation, there is just the right amount of air it's not overdone to wow you.
I wouldn't characterize the U12 as bassy, in fact I was expecting more bass quantity. Instead it was not overpowering and again I was struck how natural the U12 renders bass. It's closer to a semi open headphone bass is there, just not pounding your eardrum, to be expected with ADEL but still a surprise when you first listen. Mids are full and smooth just as I like them. Also, from what I had read I expected treble to have less sparkle and be maybe overly polite, but my first impression is very good there is plenty of detail and the right amount of sparkle to my ears, their presence is just right for me (but I get how some would like them to be more present). I like instruments timbre on the U12, again very natural and lifelike, they convey small nuances very well. One thing I noted too is how decay is very realistic this is something I often felt dynamic drivers have the edge compared to BA driven IEMs but the U12 really does very well. It's fast when it needs to be, but can linger when called upon helping the sense of depth.