After about 2 and a half months of owning the HD 600, I can say my ears have fully aclimatized to this thing and whatever burn in needed has been thoroughly met. For comparisions sake, I was really considering returning these headphones to Amazon during the first month I listened to them. They were so dissappointing. for whatever reason my ears were far from impressed. But for how the sound has changed relative to my ear over time:
First I rarely notice any creaking in the headband anymore. I am currently playing with it to get it to creek and it wont
second the sound has really become fuller. The first few weeks I had this thing, I felt that the treble was to bright, the mids recessed, and the bass simply to weak to qualify as a balanced headphone. However, somewhere along the line, my ear has adjusted, the soundstage is bigger, bass has more presence and satisfiable for its current unamped state, the veil on the mids is practically gone and I can hear better texture and clarity, and the treble is just wonderful in comparison to my Shure SE 535 (known for recessed treble).
third, To anyone considering removing the foam covering the back driver, I wouldnt recommend it, I barely noticed a difference. Plus the mod is practically inreverseable (I've put it back in with semi-satisfactory results)
Overall the experience has turned out to be well worth buying. Hopefully once I can get the E17, I can squeeze out even better SQ to this great headphone
Edited by A Kennedy4 - 2/14/12 at 7:45pm