The charts show that its pretty balanced aside from the sub bass bump. The bump is from about 0-80 hz so the beat of a song should be a bit louder than normal, which seems to be what oldschool969 is looking for.
My personal opinions (which may not be relevant because i'm not an audiophile):
Its pretty comfortable when you don't wear glasses.
The noise isolation is good
The overall sound seems to be neutral in terms of "color". It sounds a little warm with a zune hd and fiio e6, but i'm pretty sure thats the zune.
Overall clarity and detail seems very good to me
In terms of value, the koss prodj100 seems to beat everything to me. The vocals sound very good because of the mid bump apparently. Imaging and detail are awesome for the price (I would say it beats the 280 pros in imaging). It sounds really good on pretty much any genre, especially jazz. The only problem for me is that the ear cups are small.
If you want even more bass there is the beyerdynamic dt770 (better comfort, more detail, and isolation than the m50s.) and the audiotechnica athm50 (a little too bass heavy for me although bassheads would love it. Very comfortable)
I can't compare any of them against the krk 8400 because I haven't heard the krk. I can only try to imagine the sound signature through frequency response graphs. In the frequency response graphs, the krk8400 seems like the most bassy out of the headphones I mentioned.
Edited by zunehdrocks - 2/23/14 at 4:52pm