I over looked that part of 7.1.7.2 and so on. How did I miss that? Your absolutely correct about AVR's at most they are only capable of outputing umm..lets just use a nice even watt number 80 watts on a 7.1 set up and that's with a flagship AVR. As much as I am already down the rabbit hole with my modest setup I have now,
So yeah more Amps would surely have to come into play when moving up the food chain. You are absolutely right, how can we trust avr's power ratings in a 5.1 or 7.1 much less anything higher than that. My 0nkyo TX-NR656 is rated at 100 X 2 into 8 ohms and I read a pro review where "they said" it tested out at 75 watts into a 7.1. But do I really believe that? Hell No! lolo..at myself for forgetting about the amp side. So umm..yep more amps, more cables, interconnect cables, speaker wire or speaker cables more speakers have to change out the audio right to handle the add-on amps. Umm..yeah it upgrade my AVR to a flagship upgrade front mains to near audiophile entry-level speakers and stay put. Yep that's my ticket. Dam rabbit hole! You just helped me from jumping deeper down that hole Sir!
Mike