If the bass on the HD58X does come across on the light (underwhelming) side the Dekoni standard (no additional cost option) ear pads might be something to consider. I found that these Dekoni pads increased and tightened the bass on my HD650. Be aware though that theses pads also moved the soundstage a bit forward as compared to the stock pads.
EvshrugThe EV typically raise the lower and mid registers the most. After that would be hybrids. The sheepskin tend to have more affect in the upper-mids and high registers.
jaydunndidditI just got a bunch of HD 600 series pads, so I’ll be able to hear for myself. I was asking Tuneslover because it isn’t immediately clear which Dekoni pads he got.