The QS'8s are very forgiving with placement.

See the pics in this thread:
http://www.axiomaudio.com/boards/ubbthreads.php?ubb=showflat&Number=189625#Post189625

I have one QS8's against a brick wall, and one next to an opening to my kitchen. I have not noticed any weird surround effects due to one having a wall to bounce off of and not the other.

-David