It is probably indeed because the HD 600 is bass shy. I too enjoy them quite a bit without EQ, but as soon as I crave that DnB, their flaws become apparent and all enjoyment is lost.

I'd try EQ, if I were you. I recommend starting with Oratory's settings. You can also only apply the bass EQ, if you feel the rest to be unnecessary. Then adjust band three (the low shelf) to preference.