Questions? I have a Yamaha Rxv 471 receiver, 85watts per channel. Thinking of purchasing Polk rti a7's would that be enough power for the rtia7's.. Or would the rti a5's be a better choice. also how do the rti a7's and the rti a5's compare to each other? Currently have Polk monitor 60's front, csi10 center, fxi a4's rear and 2 Polk psw110's. any suggestion. Thanks.