I'd advise anyone willing to buy a 64 audio to listen to it and compare to other brand before buying to avoid a potential very expensive disappointment.
I had the chance to listen most of the well known flagship iems the previous days at e-earphones in Tokyo. (It's simply heaven for any audio enthusiasts)
At first I planned to buy a 64 audio iem beyond doubt because of the aura of this brand and after listening to either the U12t, U4s, U6s, Volur, Duo, Trio, U18s it was another story, NONE of them sounded right out of the box, I was especially disappointed by the U12t, the supposed less esoteric one. The imaging, layering, holographic or whatever was great, sure, but the tuning was just not right, it just doesn't sound right, and at $2000 it shouldn't be an option.
After Googling a bit and reading reviews where people bought them with their own money I realized I was not the only one.
In the meantime I bought another pair based on my listening experience (Thieaudio Prestige Ltd, a great find btw).
I then found this post about the U12t :
https://www.audiosciencereview.com/...dio-u12t-review-iem.32518/page-8#post-1145307
I loaded the "Full" Eq in my Qudelix and went back to the shop. It was a game changer, like an on/off switch. The U12t was now sounded right, showing more a less the proper timbres. (at the expense of a bit of imaging, but still).
I ended up buying the U12t as well because of this eq curve which correct the U12t FR without compromising its other qualities.
The Volur was just fun sounding and over priced, not much to tell about them imo. Considering its wonky frequency response I'm not even sure it can be corrected by EQ without getting too much distortion...
So, this sounds obvious for sure but do not trust any sponsored or paid review, listen by yourself and always compare with other models and be prepared to apply some Eq, it's needed for almost any iem, the best example is my Shure KSE1200 which worth nothing without eq.