The "565/dimension" shortcut comes from the fact that you get room reinforcement at the frequency where the distance between walls is a half wavelength -- half wavelength between walls = 1 wavelength round trip. You also get reinforcement at 2x the frequency, 3x, 4x etc..

If speed of sound is 1130 feet per second (can you check that while you're at it ?) then the frequency where you have a full wavelength between walls would be at freq = 1130/distance and you would have a half wavelength between walls at 565/distance.

I'm relying on JohnK to step in if I have this wrong

Last edited by bridgman; 06/17/07 10:46 PM.
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