Maybe I'm geezing, but I've wondered what happens to the unused power amps that are not utilized when a 7-channel A/V Receiver is used in a 5-channel home-theater system. I have the Marantz SR7001, which claims impressive capacity with all seven channels driven. Do these two amplifiers sit idle? Can they contribute capacity to the five "used" channels? This is never mentioned in an operating manual. I did inhale when I was younger.