Scamp, as I've mentioned several times, I'm unenthusiastic about the Crown calculator. The main reason is that if it was used as shown on the calculator page the result would be far too high. Only in their discussion page do they point out that the result pertains only to anechoic or out-of-doors conditions and suggest using a 6dB correction factor to account for a typical room contribution. Of course, 6dB means that the result would then be 1/4th of the calculator result.
What my analysis would be is that the M22 has a sensitivity of 89dB(anechoic)and the studies of Dr. Toole and others indicate that sound level in home listening rooms(counting both direct sound and room reflections)drops off about 3dB per doubling of distance. At 3 meters(also about what my listening distance is)the level would be a bit over 4dB lower than at the 1 meter measurement distance. For about 85dB at 3 meters the M22 would use 1 watt. For the 90dB peak you measured during Also Sprach Zarathustra a bit less than 4 watts would be used.
Incidentally, I've also taken my SPL meter to concerts a couple times. As compared to what I could afford when I was a student, I now sit a lot more up front and the peak measurement on the Max setting was 106dB(during the Shostakovich 5th Symphony). I also had to explain what the meter was to some rather apprehensive patrons. They were satisfied that it wasn't a bomb and likely felt that although I was a nut, I wasn't a dangerous one. To duplicate that 106dB at home(I certainly almost never listen that loud)requires about 100 watts used by an M22.
