I need to purchase a subwoofer for my system and I want a member of the RSW series. I'm running two cornwalls for mains, two heresys in parallel for center and rs-7's for surrounds. To begin with, would the RSW-12 be powerful enough for my system or should I save for RSW-15. Or if anyone can suggest better subs at a comperable price it would also be welcomed. Any input would be appreciated.