If you want to tailor the sound, get a 32 band 1/3 octave equalizer.
If you want to hear what the source sounds like, get real hifi gear without tone controls and let the HD800 do their stuff.
Let the great sound great, and let the rotten sound rotten.
This is reality...................
If you don't like reality, get what suits you, but please........ don't call it hifi.