Zak, with the couch that close to the back wall you don't have enough room behind you to really get an ideal back surround effect from the 6th and 7th speakers. If your main question is about the side surround QS8s(4th and 5th speakers),they should be a little in front of the couch, say about 3 feet from the back wall. Then do the best that you can with the back speakers despite the lack of room; put them on the back wall about 6 feet up and separated enough so that they're at least outside of the edges of the couch.
