I got these because my ipod headphones lacked the badass bass I love, and I can't carry a sub with me, so I got these, and was surprised that on some songs I could feel the vibes all the way down to my shoulders. The only downsides are that they are big and bulky, do not offer much sound shielding without music, they chew through a single double A battery every two weeks unless you don't use the amp, and if you have the bass and volume maxed out for long periods of time (2 or more hours) you will begin to get a headache.
Overall, very good product, but could be streamlined some and sound insulation could be added. If you are someone who likes the bass pumped up, these are for you, they literally shake your brain.