I have some classics (K371, K702, Koss KSC75) and the controversial Sennheiser HD 700 (sounds very nice with EQ).
Recently needed a pair of headphones for phone calls with a better built-in mic and recalled Beyerdynamic released some Made-In-China "gaming" headsets (MMX 100 and MMX 150).
I have the MMX 100 and it's pretty good. It has accentuated treble (but not like DT990 from my memory) and some kind of hole in the mids that make it sound spacious for a closed back. Good bass too. The cable though is horribly microphonic.
Not much info on this one, but there is a nice disassembly video here:
SoundGuys did a measurement of those on BK5218 and it's not horrible either.
I do get seemingly more bass than they did, though.
The Beyerdynamic MMX 100 brings a straightforward approach—No big features, just a nicely made gaming headset. Is that enough?
www.soundguys.com
Anyway, I actually like how they present music, but they just sound a bit off for games. I expected the opposite