I just ordered a Polk LsiC for my home theater. And i plan on replacing my mains (Rti100s) with LSi15s. Will i be able to move the Rti100s to the rear channels? Will having 4 ohm fronts mixed with 8 ohm surrounds have any bad effects? I noticed the LSis are not as sensitive as the Rtis... My reciever is a H/K 7200. Thanks. i hope i dont have to spend another $900 on LSi surrounds...