Mark is correct. If you had a huge ballroom-size home theater, you could set up 4 direct-radiating surrounds on each side wall and a couple at the back to duplicate the surround-speaker arrays in movie theaters.
The whole point of Axiom's quad-polar QS8 surrounds is to mimic the effect of rows of direct-radiating surrounds in cinemas, and to do it far more conveniently and less expensively.
The 10 direct-radiating surrounds in movie theaters create a big wash of direct and reverberant sounds. The QS8s, by virtue of their design, acoustically imitate the same wash of direct and reverberant sound.
By the way, in much smaller mixing and demo theaters, Dolby does in fact use multi-polar surrounds (M&K in the small theater in Manhattan). In the Criterion remastering studio here on Park Avenue, they use QS8s--in fact, an entire Axiom Epic 80/500 system is in place.
Axiom Resident Expert