We've also been experimenting with no QS10s and Stereo PCM vs. DTS. Perhaps it's no surprise but DTS is far more dynamic and clear.

What is most surprising is that we both prefer the QS10s off. So DTS but with actives and subs only. I estimate I have a 140 degree sound field with the QS10s off and it sounds more natural.

I'll also point out there's a big difference in the quality and quantity of bass with the twin 500s fed off the twin DSPs as opposed to just routing all the bass through the 800.

I'm not saying the QS10s aren't useful for music but this Eagles concert sounds better without them.

House of the Rising Sone
Out in the mid or far field
Dedicated mid-woofers are over-rated