I use the Audio-Technica ATH40fs cans. They're a staple of lots of seesion bass guys here in Nashville. Sound reminiscent of the AKG240's with a hump in the bass response. AT advises they're built as monitor headphones for drums, keys, bass, and I believe they got it right.
I use them with a Mackie 1202VLZ board as a headphone rig, and the Mack's considerable heaphone output, cued up with lots of bass in my channel does NOT even approach making them break up, even with my low B's. Don't know about Ipod or smaller device use, though.
J o e y