Dunno. I do have a aliens-like sort of head so maybe that's the reason it doesn't bother me that much. The HD800s Anax have sit on my head like most stats.

Interstingly, I don't think pressure on the HD6x0 is necessary. At least they don't clamp as much as some closed cans. It is what it is.

HD600/650 clamp for me was pretty horrible out of the box. 30 mins and I had a huge headache. I stretched both of them out over a bookshelf speaker for a day or two and also bent the exposed metal part of the headband out a bit when fully extended. Unfortunately, I accidentally stretched my HD650 out over my bookshelf speaker for longer than I meant to, and it prematurely flattened the pads a bit (though, less stiff foam, can't complain too much). But loosening the clamp on either headphone measurably brings up the treble a bit, which might actually be preferable on the HD650.

Not a whole lot...just a smidge, really. I can't remember if I posted all my data or just have it stored somewhere on my computer. Brings up the treble a tad and I think it might also slightly lower the mid-bass hump. Just a wee bit brighter sounding. Or I'm crazy. Decide for yourself!