Which subs are best for home theater?


I now have a double 12" self-powered sub that I'm using in the front channel for home theater. I am thinking of adding a rear-channel subwoofer. My dealer has suggested using a single 15" down firing sub in both front and rear channels. Would a 15" in the rear be overkill? Should I use a 15" for the front? And maybe use the double 12" sub for the rear channels?

Another question would be is a double 12" sub better on audio than the single 15" sub?

Thank you in advance for your suggestions.

MR.upgrade
mrupgrade
albert: good questions. and i will add my own: are you, marakanetz, as i assume, also retromingent? -cfb
I would have to throw my vote for an Earthquake Supernova MKIV-15. It uses a 15" woofer and a 15" passive radiator, and can pump out extremely high levels of sound well below 20 Hz. I can sell these subwoofers for less than anyone on the net, so if you are interested, please let me know.