Misfit_Toy,
I'm using three QS8's in a 6.1 configuration, hanging from a 9' ceiling (see my picture
here). My side QS8's are 14' apart from each other, so I have found that a single QS8 in between them fills the void very well. If my side speakers were farther apart (say 18' or more) then an additional QS8 in the rear would be probably be better.
The drivers in the QS4/8 are in-phase. For this reason, their overall sound is closer to a direct-radiating speaker than a dipole. I have found these speakers to perform very well with DVD-A and SACD. Yet they have enough dispersion (through the down and up firing midrange drivers) to offer some dispersion for movie soundtracks. The best of both worlds, IMO.
Jason
