Tis, welcome back; we've all been waiting eight years for your second post! The QS4s are just slightly bigger than your QS2s. For newer members,
here's the old QS2 ad. Although they were described as "The sweetest little rears..."(wonder if the guy who wrote that is still with Axiom), and Dianne R. of Oakville said that they were "...sooo cute. I had to have them!", they were discontinued.
The QS4s should be your side surrounds, directly to the sides of your listening position and about 2-3' above ear level. The QS2s can be the back surrounds, at the same height and separated about as far as your sitting distance from them(but at least wide enough to be to the outsides of the listening positions).
