never eq the bass up, only eq everything else down. i use electriq on foobar and would recommend using a parametric eq. others use graphic ones and swear by them. if you want, pm me and ill recommend some settings or whatever, right now iv got to rush out for work -_-
I'm pretty sure it doesn't matter which way you equalize because you're still limited by the potential of the amp/headphones.
It's okay to EQ things up as long as you preamp down by the same, or more amount of dB to give it more headroom