I am on my second pair of TH-900 mk2 (first pair I had driver failure) and I really enjoy them but definitely need EQ for me to be enjoyable.
I boost the mids and pull the treble down A LOT.
For me the bass just needs a bit of a boost and they don’t actually sound as “bassy” from stock as the graphs show.
Not sure if this is due to the super poor clamp force these have on my head as I must have a
small head.
I do like a lot of bass compared to most and I find the bass quality is incredible and one of its best strengths but not as “punchy/slamy” as some people make out. I find focals still beat these in punch/slam by a fair bit.
For refence the clamp force of the LCD-5 AND HD600 is perfect.
The LCD-XC 2021 and especially the TH900 in comparison feels lose on my head like they will fall off if I move my head to fast.
Also the TH900 have a plasticky timbre that can be improved a bit if using on a tube amplifier.
Anyway I thought I would share my thoughts on them.