Time to mod: I started out with dampening the back of the driver with closed-cell foam. Helped a bit. Then, I installed open-cell foam inside the pads (the same foam as included with Beyer pads). That helped immensely at the expense of top end air, but worth it to me. I also tried LCD2 pads with and without the open-cell foam. I kept the foam inside the pads for a more forgiving tonal balance. In essence, I truly do not like the 550, but given its application (used in conjunction with a uDAC2 in a portable setting) they'll do fine. On the basis of pure sound quality, I don't feel like they match or better any cans in my stable, other than the Sony V6.
I really wanted to like them.