We recently moved into a new home with a different home theater setup than before and as such I am contemplating adding a 2nd sub. the new theater is 15x15x8.5 but is open on one side into another area of the lower level (another 500 sq ft or so). Being the lower level, it is on concrete. I have a Klipsch speaker setup - RF62's in front with the matching center and surrounds. Receiver is Denon 3313ci. the subwoofer is an older Klipsch model - an RW-8. I like the idea of having 2 subs and would like to proceed with that unless someone has a strong argument against it. the question is can I purchase a current Klipsch Sub (maybe an SW-110 or 112) and use it in tandem with my RW-8? Looks like I could pick up a used RW-8 on ebay or craigslist for about $150. Would that help my situation at all? Total budget available right now is about $600 so buying a pair of new ones isn't really an option. Thanks for any suggestions!