To Warnerwh: My understanding is that SPL falls off by 6 dB with every doubling of distance from a point source (assuming anechoic conditions). In a reverberant environment like a living room this holds true over fairly close distances, but then as the distance increases the reverberant sound will bring up the SPL by a few dB over the predicted anechoic level.
Sound pressure level falls off by 3 dB for each doubling of distance from a line source under anechoic conditions, and once again in a reverberant room the fall-off is a bit less than the anechoic prediction.
Measurements I've taken support these figures.
Duke
Sound pressure level falls off by 3 dB for each doubling of distance from a line source under anechoic conditions, and once again in a reverberant room the fall-off is a bit less than the anechoic prediction.
Measurements I've taken support these figures.
Duke