Apparently, we have a similar situation. My basement ceiling is about 7 3/4'. I placed QS8 number one on the left (full) wall about 6 3/4' feet above the floor (about a foot from the ceiling) and the second QS8 on the right partial wall heat duct 18" overhang thingy about 7 1/4' feet from the floor (about six inches from the ceiling). With sound shooting out and bouncing in all sorts of directions from the QS8, all is well.

Phil