NO.. it will have a set standard wattage per channel.. be it 80, 90, 100, etc. so, there will be no increase of wattage to the channels in a 5.1 set-up, if you are using a 7.1 receiver.
although, and i am sure this will start a small controversary, it is debatable that the more channels driven, the greater the decrease in the wattage stability per channel. in other words, the HARDER you drive the receiver(volume), the harder it is for the receiver to send a strong wattage signal to the speakers.
bigjohn
