Sound System Design Equations
Sound Design Equations
Sound Power (W) - the amount of power a source converts to sound in watts.
Sound Power Level (LW) - a logarithmic comparison of sound power output by a source to a reference sound source, W0 = (10 -12 watt).
LW = 10 log 10(W/W0 ) dB
Sound Pressure (P) - pressure associated with sound output from a source. Sound pressure is what the human ear reacts to.
Sound Pressure Level (Lp) - a logarithmic comparison of sound pressure output by a source to a reference sound source, P 0 (2 x 10-5 Pa).
Lp = 20 log 10(P/P0) dB
Even though sound power level and sound pressure level are both expressed in dB, There is not a direct conversion between Sound power level and sound pressure level. A constant sound power output will result in significantly different sound pressures and sound pressure levels when the source is placed in different environments.