I bought a set of Sennheiser HD280s (as an "upgrade" from some Sony MDR-V150s), but much to my dissapointment, the Sennies have almost no bass, whatsoever. And I'm not being picky, either -- there is literally no bass, unless I press the cups to my ears. Does anyone have any suggestions? I'm trying really hard to like these, but right now my V150s are sounding 20x better than the HD280s. 
