Currently have a pair of z313 from logitech. Looking for a 2.1 or 5.1 system with a ton of low end, Currently have a soundblaster audgy (need a half height card for a bit) and will be having an xfi music in a couple pay checks. I want these to be reasonably priced, $100, and make me be afraid to turn the volume to max, and the base should rattle me a little. your help is appreciated (by all except my neighbors)