Today was a fun day of demoing a bunch of gear I'd never heard (Yggy, Black Widow, Ragnarok, HD800/S)
The main attraction was the chance to directly compare the T90 to the HD800 and 800S.
I was actually pretty shocked. I did not totally care for the HD800.
IMO my modded T90 was (mostly) better. The 800 has a dip in the upper midrange that was very distracting. It almost made them sound muffled compared to T90. Thats an exaggeration of course, as the 800 has a ton of detail/resolution, I just feel like the recessed mids make it almost pointless because some of the definition is buried with the recessed mids.
The T90 is clearer sounding. And it presented more detail because it does not have recessed mids and has a bit more treble.
The HD800S was better. The mids weren't as recessed and it was less sterile with a warmer signature. Using a balanced cable made the differences even more obvious.
I almost couldn't even listen to the HD800 v1 without a balanced cable, because the recessed mids gave it a weird stifled quality. When I would switch back to the T90 I could hear all sorts of detail I wasn't hearing on the 800.
Not to mention the T90 is warmer and much more "fun" sounding. I understand what people mean now when they say the 800 is sterile/clinical. It did not bother me very much, but it did keep the music at a slight distance, keeping it from totally engaging me. Everytime I switched back to the T90 my mood brightened.
The only the 800 seemed to do better was soundstage. The depth and 3 dimensional quality and ability to arrange sounds in space was extremely impressive.
I wouldn't mind owning the 800 but I'd absolutely need a balanced cable for it. It sounds much better balanced.