Ifyou go to the Klipsch web site, search for your speakers (RF-7) then click on FAQ and scroll down. They have a very good chart that shows a speakers effeciency and the amount of power needed to achieve different SPL's. Your RF-7's would need 64 watts to achieve 120dB, my inefficient NHT's would need 2048 watts to achieve the same SPL. Your center would need about 300 watts for the 120dB. In the larger picture I doubt you will listen to anything at such levels. Maybe the chart will help put SH's advice into perspective.