I recently bought a LSI Center speaker. The speaker is supposed to be run at 4 ohms. I have a Yamaha receiver model rx-v2300 which only supports 8 or 6 ohms. I turned the receiver to 6 ohms. Is it o.k. to run this speaker at 6 ohms or will it damage it. My system is a 6.1 I have the LSI as my center, mains are RTi 800's, rear's are F/X i30's and my rear main is a CSI 40. Also I recently purchased RTi's for the mains and the right speaker seems to be making noises as if the driver is blown. Is it difficult to replace the drivers on this speaker. I never did it before. I imagine you can buy replacement drivers from Polk. Is that correct. Thanks.