Hey guys I just got my HD650 and I have to say that I am blown away! Not because the HD650 is technically better than the DT250 but I am just utterly bewildered how the DT250s sound sooo much more enjoyable and natural (in terms of tonality). Well that doesn't mean that the Sennheisers sound bad but I just can't stop thinking of the DT250's sound.
What I appreciate about the HD650 though is that it has good instrumental seperation and air. Now, I'm still not very good at using audiophile terminology but I felt as if the HD650 lets me "feel" the sound in addition to hearing it (texture?). Oh, and the bass reminds me of my M50, only that it is a lot tighter and faster.
On the other hand, the DT250 may not sound as technically good and may not have as much detail. BUT I just seem to have enjoyed the sound of the Beyers a lot more. One distinct trait that I can make out is the mids. Paired with my E17, the mids just sound so liquid, warm and smooth. It's just so pleasurable that when combined with its nice balance of bass and treble, it gives me the nicest audio experecience compared to the other headphones that I've owned and auditioned.
Darn, this feels so frustrating that I might just repurchase a DT250 so that I can concentrate on my studies instead of thinking about audio! =D