According to the numbers you gave me, you have a 14,040 cubic feet listening room and asuming you have moderately sensitive speakers (88db) with an 8 Ohm impedance, what can i say, you'll need something like a MultiChannel Parasound Halo to fill your listening room with adequate sound pressure levels. Your listening room is to large.
This receiver is capable of filling a 3,000 cubic feet listening room with adequate sound pressure levels (according to THX certification).
You can do two things:
1. Buy a dedicated power amp for each channel, or at least for the mains and the center channel and use your receiver for the surrounds (expensive).
2. Change your receiver to another room (less than 3,000 cubic feet in volume).