Are there any ear pads that are larger and fit on these headphones?
-No, the HD6 MIX, HD7 DJ, and HD8 DJ models can only use the stock earpads that are included.
Are the Momentum 2.0 ear pads larger?
-No, actually the M2 around ear earpads are even tighter than the DJ models.
I've owned 6 or so Sennheiser headphones and love the ear pad size. I use the HD 598, HD 555, and HD 650 on an almost daily basis.
-HD500 and HD600 series have some of the largest earpads that we've ever put out, which is probably why nothing else will do it for you. Your only other option would be our HD380pro which has an earpad size the same if not larger than the HD500 series.