Hi, The avr330 is a 7.1 receiver. The speaker layout does not show a 5.1 set up. They assume you are doing a 7.1. I am doing a 5.1 right now and in a few weeks will add a rear center speaker for a 6.1 Exluding the fronts there are four surround back speakers shown in the 330 manual: Surround Left (shown on rear left wall) Surround Right (shown on rear right wall) Surround Back Left (shown behind listener on left back wall) Surroung Back Right (shown behind listener on right back wall) which outputs on the receiver do i use for my two back speakers? The Surround L/R or the Surround BACK L/R? When my extra 6.1 speaker comes in next week where do I connect it? Thanks.