I know, I know, Skullcandy, but has anybody tried these? They have a self-contained "amp" to boost bass. I expect it's not really an amp but instead is the headphone equivalent of those vibrating transducers you mount under your home theater seating. The effect is powerful nonetheless. With the bass boost slider turned all the way up it felt like I had my head right next to a good subwoofer.
I don't listen to a lot of bass-heavy music, BUT I do watch a ton of movies at night where I have to keep the volume down so I don't get to "feel" the LFE so this might be a substitute. It's an interesting gimmick.