I have a surround sound setup with Yamaha RX-A770 Receiver - Monitor Audio Bronze 2 speakers up front - monitor center and 4 monitor CS160's in the ceiling - My amp allows me to set the ohms to 6 or 8 only for all my speakers - My Bronze 2's are 8 ohm and my CS160's are 6 Ohms. Which one should I select? - I have it at 8 Ohms currently and it sounds good