which is best? i have the denon 3805, a huge room 35' x 40' x 10'. the 8' projection screen and 7.1 are positioned fine (i still have to play around with the sub placement however). the seating area is about 15' away from the screen, but off-center, because of a support holding up the floor above that's in the way. this used to be a church. now my question....is it better to use an spl meter with calibration disc, or a denon reference mic to get everything setup properly? this is used mostly for theater. thanks.