Sonic Defender
Headphoneus Supremus
I have 7 other headphones to compare with, it's not the material. It's certain frequencies that get hit during the songs that makes it apparent. Another person mentioned in this thread as well, in addition to someone in the /r/headphones chat. By the way, it doesn't sound bad, it just sounds kind of weird. Not something I've heard with a headphone before.
I know what you're saying, but I would propose that the headphone is the constant, it doesn't change, the material changes, so if the anomaly exists with the headphone (constant) it should always be present. I suspect it becomes debatable at what threshold something becomes noticeable with different headphones, which I think is really what you are detecting, and I think this is true of all headphone designs, but design parameter dependent. For instance today with my PM3s some Holly Cole seemed to get a little shouty in the vocals at some intense points, but at home on my speakers (I know not the same thing, but humour me) the shoutiness was gone, and with my 400is less noticeable.
I guess in a long-winded, blow-hard way I'm saying it is the intersection of the material and the headphone, so really we are both describing the same thing from a different perspective; which means, I have just wasted a few minutes of everybody's life who has read my comments. Doesn't that feel good?