I'm curious as to why you have your sub set at 80 when you are also using the crossover in the receiver? Seems redundant. I know when I got my SVS they recommend that if you are going to be using the receivers crossover, there is no point in using the sub's. Crank the crossover on the sub to max as it's not doing anything anyway. Why add yet another crossover into the signal path when you don't it!
:-)
On another note. I'm also running the QS8's and you will find on some movies etc that the surround mix is subtle. This is normal as has been mentioned above. Keep in mind they are surrounds, not mains!
