All headhphones have some sort of bass response david
The driver/cones with most headphones now can reach the lowest we can hear and lower, 20hz, or even 14hz which seems to be the lowest with headphones with neodymium drivers which are much more responsive than older forms of cones. (The ones Apple uses on I-pods do use neodymium drivers by the way, which would explain sound quality and clarity
Expect headphones like DJ sets to be more expensive that use this driver/cone though, which would be enclosed and so give more bass anyway
These in that case can have a massive bass response with the right electronic equipment powering them, though most devices can only emit 20hz to 20khz signals anyway to the headphones, but those drivers are of the best quality.
haha Subwoofers hehe...its just like having one though, because the drivers/cones are smaller, they are lighter, creating lower bass that even some large speaker systems would like to have. Though of course they dont have as much wattage, so they can't be as loud as speaker systems, and this is another factor limiting large speakers (they would have to move more to create a louder sound, again limiting bass response)