Yo,
After my long break from this forum, I have returned!
I just got these in from Koss today and initial impressions are incredibly positive. These are Koss' second best headphone available that I have tried (DJ100, DJ200, PRO4AA, PRO4AAT, PRO4AAAT, and MV1). The overall tone of these is warm, detailed, and bassy. The tone is in ways similar to the DJ100, with them being bassy and warm, but these are more detailed and airy. They are more like a DT990 junior, but don't have the dip in the mids and have a smaller soundstage. They honestly stomp the DJ100 into the ground from my testing.
DETAIL/TRANSPARENCY
Detail and resolution is quite good, much better than the DJ100 and even their older MV1 (which wasn't all that great a headphone, ouch!). Right now I am comparing them side by side with the KRK KNS8400, and they are on par when it comes to detail retrieval and transparency, but have added warmth and much more bass.
TREBLE
Treble is really nice on this headphone, and while I would consider it bright, it is never strident or sibilant. The treble is quite smooth and articulated, something that is noteworthy for this headphone considering the price. Extension is quite good but rolls off at the upper most registers.
MIDRANGE
The midrange is surprisingly not lacking like the PRO3AAT, but not quite as full bodied as the DJ100. They are noticeably warmer and forgiving than the KRK KNS8400. But don't let that make you think they aren't as detailed, they sure are. I noticed the lower mids blend in nicely with the bass and never seems muddy or out of place. At least they aren't like the Fidelio L1's lower mids where they bleed into the upper mids.
BASS
Oh yeah the bass, it thumps a ton! Not quite DT770 levels, but a ton more controlled with good extension. Still quite pronounced, at least as much bass as the Beyerdynamic Custom One Pro on the third adjustment notch. Still very well controlled and never feels bloated, even with bass heavy music like Dubstep and Rap. Quite a feat indeed.
SOUNDSTAGE
My main gripe is their soundstage isn't that big. It's rather small, perhaps smaller than the DJ100 and most certainly smaller than the KRK KNS8400. But it's not terrible or flat, just more narrow. This gives these headphone a more Grado-esque presentation, as they are a more forward headphone with the treble and bass.
Overall I am incredibly surprised by these. I'd wager that they are better than the KRK KNS8400. These however are not "studio" headphones. They are not neutral as Koss marketed them. They are warm and bassy. But now the question is how do they compare to the ATH-M50? Well I don't have one to compare to but these are easily the best under $200, perhaps more than that. I really, really like them, and I rarely like stuff from Koss.
