I also did a manual EQ thing. http://www.head-fi.org/t/111193/orthodynamic-roundup/20505#post_8727076 (raw graphs). Same idea - first mod the phones with felt until the sound is decent, then measure the response, remove the mods, and manually EQ the stock configuration until it measures the same as the modded one in frequency response. In the end, it didn't take too much effort to match the responses, and the decay measured much the same too.
I wondered what the point of doing physical modding was when the same could be done with EQ. But I did kinda think the sound was a slight bit more harsh with the EQd version - whether this was real or imagined I don't know. The benefit was that you lost no soundstage since you didn't need to put any extra material into the cups. (Though this raises the question of where the soundstage is if not in the frequency response or decay.)
Edited by vid - 3/9/13 at 5:57pm