At the moment I am using the Mordaunt Short 500 series THX system with a Pioneer VSX-D912 Amp and a Pioneer 565 dvd player. The front speakers (502's) both have 10" subs in them. I think they normally work pretty well to deliver the bass needed for loud films. However, I was wondering what you thought on adding another sub to the system, namely the Mordaunt Short 309W. The system is being used in a large room at the moment which means everything needs to be turned up that bit louder. I was wondering whether this would ease the strain placed on the front speakers as I find they tend to distort when pushed quite hard. If I was to go ahead with this extra sub I think there may be wiring complications as the amp has no extra sub connections, and am not even sure if its possible to wire it all up. Any ideas are appreciated.