A friend of mine wants to get a "system" for his PC at home for when hes not in the car. He has a standard dell workstation and although I have not looked in the back, Im sure it has on board audio. He has a budget of $200-$250 and wants something that hits hard bass wise (all he really cares about is bass) Any suggestions? I dont know anything about computer audio so I was wondering if he could just buy a sub and hook it up or will he need a receiver etc? Any help would be greatly appreciated.