At the advice of a forum member, I upgraded from a Sennheiser HD 280 Pro to a Senn HD 558. I must say I'm a touch disappointed, especially given the price difference. My impression of the 558s is that they have better mids than the 280 Pro, but on the 280s the treble seems more "forward". The bass on the 558s is tighter and more controlled than the 280s, but the 280s seem to have more punch than the 558s. All these factors seem to make listening on the 280s a more "exciting" proposition, which is strange considering they're supposed to be professional, neutral sounding phones. Supposedly the open 558s have a much better soundstage than the closed 280s, but I'm just not hearing it. I do notice an improvement, but it's not significant. The one place where the 558s get a clear win is in comfort; they're far more comfy than the 280s.
Do my impressions match anyone else's? Would using an equalizer help much? Unfortunately, I listen to many music videos on a computer, and the EQ options on most video players are lacking. Should I be looking for cans with more pronounced treble?