hmm...there is an impendence switch for 8 and 4 ohms on the back of my receiver. on the position i have it on now is for 8 ohms on the mains, center and rear channels. but if i flip the switch, my manual says that i should have 1 set of mains that are 4 ohms or higher each (or 8 ohms for each speaker if using 2 sets a/b), and 6 ohms or higher for the center and rear channels. would this switch limit the output of power if i were to set it on the lower impendence setting, or should i just leave it at the 8 ohms (for more power?)? because the switch seems to be pertinent to the speakers that i have/will buy.