I put some Equation RP-21 earpads on my Beyer DT660. Warmed them up significantly and they finally have the lowend impact i always wanted them to have. Down to 20hz there is a good amount of energy with these pleathers. The phones now sound much more balanced and almost relaxed. Using Sinegen i also found that the former dip@ 3khz turned into a little peak (2-3db (2700-3500hz) which seems to expand the Soundstage which i did not expect at all because i've read somewhere that dt770 have a narrower soundstage with pleathers instead of velours . My DT660 keep their lower treble peak 5-8khz, that gives them their almost open sounding Signature. Theres a little less upper treble of which there was plenty. Though i think there is a bit less upper treble around 10khz up i can here more details in the mids now. Looks also changed a bit as the pleather pads are smaller than the original velour pads. They don't look "that huge" anymore.
I hope that the pic upload is alright as i was not allowed to upload any pictures via my forum account (sorry first post)