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Taking into consideration the effect of the inverse square law on the propagation of sound waves in free air, how would you calculate the loss in dB per meter? For example, a sound source, a one K tone burst produces a level of 90 dB at 3ft. away from the source. What would be the level in dB at 100yds? If possible, establish a norm for temperature and relative humidity. Just a musician trying to design an outdoor sound system. Thanks!

The direct answer to your question is that in terms of power, dB(100 yds) = dB(3 ft)-200, assuming a pure inverse r-squared law.

Jack L. Uretsky

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