http://www.axiomaudio.com/tips_subwoofer_placement.html



for the answer to your sub placement question...



i had my qs8's about 6" behind my head in my last house. and it was fine, just get an spl meter, with one of those, you can fix any placement issues, remember you can change the level, delay of all of your speakers, with a good receiver... so even with poor placement the receiver can make up for that short coming, of reality..