Graham, a few thoughts: 1)fill the stands with sand bags; 2)place the QS8s on the back wall about 3' above ear level and spread as widely as possible(they're still side surrounds), maybe to about a foot from the side walls; 3)sure, plugging it in at the same spot will make it less likely for a hum to appear because of a ground loop between different electrical locations;4)a regular fan would help a little, but the general idea isn't to blow air over the receiver but to have a fan located so as to suck air out of the vents more quickly. Does the 806 absolutely have to be crammed into this compartment? Can't it be placed somewhere higher up on the TV stand where it wouldn't be enclosed?
Congratulations, and enjoy the great sound.
