How do you know if the sound is just because the headphones can resolve it, or because there's a frequency bump? I haven't heard this effect with any low-tier headphones, some of which also have that 1-3Khz bump.
Either that or its just the extra detail the HD800's have picked up. I've experienced it too (HD650), the quiver in the singer's voice, inhalation/exhalation during notes. It's not sibilance in any way.
I would agree if the treble cut-off was really abrupt. AFAIK its quite a gentle dip, enough to remove the harshness. The amount of detail that is revealed always makes me like them, even when I switch to them from the relatively brighter and bass-heavy HD239. Obviously, it doesn't suit all kinds of music. Something like rock or metal wouldn't be as 'clear' I guess, no matter how long wait for your ears to get accustomed.
Sometimes it's not the headphones but the particular album. At other times it's just your mood. How you perceive your senses has both external and internal variables.So, if you don't like the sound initially, approach the matter with an open mind and try to find what's the problem. If it *is* the headphone then it won't change over time.
A new phenomenon is to make higher priced vinyl copies with better mastering than the CD.Take the DaftPunk RAM, for instance. The CD peaks to within -0.01 db, and has a dynamic range of about 8db.The vinyl peaks around -2db and has a dynamic range of 13db.I can only assume that record companies have stopped counting CD listeners as "serious".