Thanks, but I'm not looking to buy additional equipment other than inexpensive adapters if necessary. The system I just bought was only $180, and I can't afford to spend substantially more. The passive sub is actually good enough for my application, but if it was a matter of spending a few bucks to convert speaker wire to RCA and I'd get better sound from the old sub I would have done that. It looks like that's not the case, so I'll just use the new system as intended. Thanks for the help guys.