Alan..
Man, I'm always getting things backwards ? hahaa.. But, those QS8's mounted on the back wall have sounded great to me.. Both with movies and with music.. Full and believable..
So, the side location needs to be just forward or rear of the seating area ? 20 degrees, eh.. I will have it all installed and fired up by this Sunday (best laid plans of mice an men ?) I post my findings Monday.. This is going to be so cool.. I can't wait !!

LFE ! The rest is just details..