HI and Thank You for clarifying the M80's dual 6 1/2 inch drivers
not being subs.

corrected room dimensions:

18ft x 13.5ft x 8ft = 1944 ft3

listening distance ~8ft , varies tween 6-10ft
listening level ~ -41dB , movies and music

Listed are various listening levels per device/media:

bluray via hdmi to denon 788, DVD set to DTS 5.1
e.g., Norah Jones "live from austintx" -53.0 dB = low to quiet
-40.0 dB = low to mod
-28.5 dB = fairly loud
-19.0 dB = very loud


Thank You very Much,
Lawrence