Pros: Tight bass, clear midrange, sound isn't too closed, better than average soundstage for the headphone type
Cons: splashy lower treble, bass might be a bit light for some, below average noise isolation
The Sennheiser Momentum on-ear is a gorgeous-looking headphone just like the original one. The alcantara earpads is very comfortable and the headphone is light so it doesn't feel like its pressing your ears as is the case with most on-ear headphones. That's a major plus to me considering it's on-ear
The overall sound of the MOE (Momentum on-ear) is balanced. It is definitely not dark but doesn't sound lean too. Bass has good extension but I believe it's not as full-bodied as say the DT1350. Nevertheless, there's no bloat at all here. Midrange comes of clearly but those who are used to warmer-sounding headphones might find the midrange to be somewhat not forward (slightly recessed). However, the midrange is definitely clear as a whole.
Treble comes in prominently starting from the lower treble region. I did find it splashy and a little artificial albeit in a very minor way. The splashiness makes the overall presentation livelier but at the same time, it can sound a bit hot if you have audio tracks that are heavy in this area. Going up into the higher frequencies, it would roll off gently making the upper highs very laid back. Overall, the treble is a bit uneven and sort of soft-sounding. I feel it's not completely free of grain as well. I think calling it mildly v-shaped is reasonable
Soundstage is better than sealed on-ears that I've heard. It's not definitely big the overall presentation doesn't sound too closed. And probably that is related to MOE not having good noise isolation. I have to turn up the volume a bit since it doesn't really block out much. The headphone doesn't leak sound though.
Overall, I find this to be a really competitive headphone for the on-ear sealed category. Pictures and some other feedback can be found in my Momentum on-ear review here.