I have Ultimate Ears UE-10's, and they are the nuts for bass . . . with the dual low transducers, they have such a solid low that you can swear that you feel air moving in your ears. As others have said, though, not cheap . . . about $1K for the monitors alone, all things done. And the custom fit is awesome - great isolation, and if they ever feel out, my ears would go with . . . these things just fit GREAT!
I use that with a Sennheiser 300 series IEM wireless, and the sound quality is unreal . . . better than most studio monitors . . .
Bongo 4HH, Lava Pearl/Moonstone
Bongo 5HH, Stealth
Bongo 5HS, Carbon Blue Pearl/Abalone
Stingray 4 30th Ann.
Stingray 5 HS 20th