I had a pair of 803d's in a medium size room - 17 x 13 and thought they over powered it and took them out. The 804d2's may have been a better fit, though I never compared the two. My 803d's did love power though. Went from 1 MC352 to 2 MC352's to a pair of MC601 Mono's and noticed improvement with each upgrade. I only used 6 to 60 watts max.
