These are pretty neutral headphones, a little soft on top but very nice midrange. Great for vocal music, especially female vocalists. I don't hear the reported "haze" in the upper octaves, nor do I have the sense that they lack anything in the bass. These are definitely not for a basshead, but if you like a balanced sound, with a taut bassline, then you'll appreciate these cans. I listen mostly to jazz, so these headphones are perfect for my tastes. Classical music sounds pretty good through the Senns, but Mahler and other large-scale works can get a little bit congested in the upper octaves. Cymbals can be a little tizzy on top if the recording veers in that direction, but good recordings seem to be pristine. Deep bass holds up pretty well except for the levels in that first octave, where they tend to drop off a bit. I have several recordings of solo pipe organ on 1/4" tape that sound very good through these phones, but the 32' bombard is well down in level, but still there. Old-school rock-and-roll sounds pretty good through them, but some of the newer heavy metal type music doesn't fare quite as well -- I actually prefer heavier rock music through my closed-back Philips Fidelio L-1's. Oddly enough I don't think the semi-open Sennheisers bleed sound to the outside any worse that my closed-back phones do. I wouldn't be concerned about using the Senns with a portable device, and the shorter cord that came with the Massdrop HD6xx makes that practical. They do seem to be fairly easy to drive; I can get plenty of volume through my Galaxy 8, but not with the same SQ as I get with my system. I've been driving these Sennheisers with a couple different headphone amps (the Cavelli Liquid Spark is pretty awesome by the way) and there's more than enough volume, and I like my music LOUD. Plugged straight into my home theater receiver there's enough volume to make my ears bleed, so most any device should power these phones. Overall I can't think of any real negatives with these headphones. I could have used the 10' cord, but even that might not have been long enough, so no great loss. But they do a good job with every type of music, and excel with jazz, classical, and vocal. I guess I'd call these headphones the best all-rounders I've ever owned. They don't excel at everything, but I don't think any headphone does that. For my needs they'll be the headphones I reach for most of the time, so I'm quite pleased with my purchase. Everybody should own a pair of these, if for no other reason than having a benchmark to judge the sound quality of all the other headphones out there. If you want a real treat, plug your turntable amp directly into your headphone amp, and put on your best, favorite LP -- you'll experience the best eargasms you've ever had!