Take for example the Marantz sr4200 which is rated at 70x5. NOw it appears common knowledge that this reciever will not put out anywhere near that power with all channels driven ( lets say 30x5). The question I have is does the power to every channel drop to 30W as soon as you go to 5.1 mode. Or do they do some tricky stuff. The reason I ask is because in a movie you will probably never drive all the speakers at the same volume. I hope this makes sense.