Hello all, I have been a longtime lurker here, but never posted anything. Following this thread to support the blind buy helped me a lot, so I feel like contributing. Bear in mind this is much more of a initial impressions than a review.
Mine have arrived today, and they look gorgeous:
My initial amazement was with the driver size and how they felt on the head, it seems like Iām wearing a helmet over my ears, and yet I have 100% transparency, so they are very very open, much more than the 6XX and MUCH more than my DT 880s.
With sound, that amazement persists with soundstage and imaging, as it is big and wide, definitely due in part to their open design.
They sure are detail monsters, and can be too much for my 6XX accustomed ears at times. Everything is bigger and wider, finesse and sparkle is show much more clearly, SEPARATION and IMAGING being the big words here. I put on the new Let it Be remix from the Beatles and felt like that there was a concert playing around me.
Bass is linear, but too linear for my liking, thatās where EQing comes in though. Shelving them produced a very neat result, although different from the pillowy effect I had with the 880 and the 6xx. I donāt dislike neither the pillow nor the planar sound, they are just different. With my dynamics I feel the slam much more than with the XS, where I feel the actual rumble of the headphones. It can be called a slight resonance, maybe, and I suspect this after seeing CSD graphs of the other headphones, but they are not audibly bad (I canāt say for distortion though). I have pad swapped my DT880 with brainwavz XLs and those resonate like crazy and are terrible.
Mids are indeed the weakest link of this headphone. I havenāt listened to Hifimans in person before, and I see that their reputation precedes them: mids are thin although detailed. Coming from the linear mids of the 880 and the vocal richness of the 6XX I was a bit disappointed, but not much, as I had been warned. If you are used to less substantial mids like with the Sennheisers, the mids here wonāt be much of a problem. For me they need further tweaking, so I added some gain between 1500-2250 (low Q and mid-high Q, respectively) and the effect was very good. They approach my sennheisers more now, sounding more āveiledā but yet tonally correct for my ears.
Highs are the high point here. As said, these are VERY detailed, and that is unfortunately noticed, for my treble sensitive ears, with some sibilance and quirkness over 10khz. Dialing this down was easy though.
Here is the EQ profile Iām using as of the moment, while no FR graphs are out yet (pre-amp is just very aggressive anti-clipping safekeeping, I power these from my L30 and they are very efficient):

Overall they are a good pair of headphones. It is to soon, and Iām to skeptical and ASRbrained, to call them more resolute, transparent, fast etc, than my mid-fi cans, and a very neat experience when considering the difference in technology and driver size, and a superb pair if you donāt mind EQing.