Just like I can't imagine that the hd800 would sound 200x better than your HA-EB75, we know that to get a significant increase in sound quality, you usually have to add a 0 to the price. Also beside technical achievement of each headphone, taste matters.
The pmx680 are as open as your HA-EB75, and provide impressive bass. (at least it's the best bass I've ever heard from an ear bud).
Edited by extrabigmehdi - 6/5/12 at 9:16am