My idea was to use a receiver with multi-channel analog inputs, was to take a dedicated playback device (like a CD player), and run it into the DSP's inputs, then take the DSP outputs, and run front channels into the L&R mains, and the rear into the L&R surrounds, and then power the speakers with the outputs on the receiver.

Pioneer PDP-5020FD, Marantz SR6011
Axiom M5HP, VP160HP, QS8
Sony PS4, surround backs
-Chris