I strongly, strongly recommend AGAINST the Klipsch S4. The treble for me was so harsh, it rendered them unlistenable. On top of that, mids are recessed, and that's where most of the crunch in metal music will be. I love Iron Maiden and the S4 did them no justice. I actually bought them for $34 and still found them to not be worth anything close to that price in sound quality.
If OP can use eBay, the answer for his question begins and ends with Vsonic GR06 (strong bass, strong mids, strong volume, $63). If he can't, then maybe Meelectronics A161 (less strong bass, awesome mids, strong volume, $100) or Sony MDR EX310 (strong bass, strong volume, $85).
S4 treble harsh and mids recessed? Wow, that's not what I heard from them at all. In fact, the treble was lacking sparkle and mids were forward, with a little bass bleed through. Did you burn yours in?
But of course the S4 aren't the best bang-for-your-buck.