I have dt990s (250) hooked up to e7/e9 double and at certain bass frequencies they rattle or distort in one driver (left one). I have them plugged via USB to my computer but the Line-out does the same. It also did it with this http://www.djstore.com/item/novnio24.htm.
I used to have Audio Technicas (32 ohm), and they did the exact same thing, in the same channel. If therefore seems unlikely to be a hair or something because I opened them up and found no problem there. I would have though my amp was enough power.
It is not hugely distorted, just at certain frequencies and tends to happen at all but the lowest volumes. Driving me crazy as I other wise love them!
Any ideas appreciated, thanks!