The fronts are essentially actively biamped, so six channels feed the front, center, and right mains. Then there's four surrounds, so that adds up to ten channels. The subs are running off the S800s as bridged units, so that's all four channels of those two amps, totaling 14 channels.
The S400 is not part of the main system but will be employed to drive a second two-channel zone, so there you have all sixteen channels.
I could have left the S400 out, but there was plenty of room and it seemed extra cool to have a five-stack of amps, which makes this stack 25% bigger than the other guys who got the same system.
Sheesh! Who's acting like a kid now?
As for the OPPO, it's tempting, very tempting...