I would like to share my experience with hd800 (about 3-4 months since purchase). Sometimes the treble bothered me on some recording, sometimes it not. I've tried to eq it a bit (3-4db), but it seem the air around vocal seem reduce as well.
I read somewhere that jitter effect most in this frequency region. So I start experimenting on jitter reduction, using audiophilleo, audiophilleo with battery mod, jkenny mk3, jkenny ciunas and finally settle in with my friend sonicweld diverter (he bought a dac with good usb connection). When I progress with converter, I noticed that the more I progress, the less I bothered with this frequency region. I also exprimenting with usb cable and bnc cable, some better and some make it worse until I settle with my current one.
So I come to the conclusion (IMO of course) that the problem with hd800 in this treble frequency might being increase by jitter. Once we minimize these, we might not have an issue??
I'm quite curious whether anyone use a good analog as a source to feed hd800 and still have a problem with this frequency. Sorry for the rambling as well.
Edited by jsgraha - 7/2/13 at 5:32pm