I hardly every notice any sound from my single rear QS8 from my 6.1 setup. Typically they are only used for added ambiance to help fill the room with sound. My side surrounds are to my forward position because of the mounting limitations in the room. I get a lot of extra sound out of them and they make a noticeable difference.

https://docs.google.com/spreadsheet/ccc?...amp;usp=sharing