PA System Calculations

Some Commonly-Used Sound System Calculations

Use the left-hand field(s) in any row to enter values. The result will be displayed in the right-hand field(s) in that row.

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Signal and Power Levels


Input Voltage Output Voltage dB Difference
Input Voltage dB Difference Output Voltage
Volts dBu
dBu Volts
dbV dBu
dBu dbV


Power 1 (W) Power 2 (W) dB Difference
Power 1 (W) dB Difference Power 2 (W)


Output Levels


(dB SPL, 1W/1m)


Peak Power (W)


Peak SPL (dB, 1m)

Cabinet SPL (dB) Number of Cabinets Combined SPL (dB)
SPL 1 (dB) SPL 2 (dB) Combined SPL (dB)
SPL @ 1 metre (dB) Distance (metres) SPL @ Distance (dB)


Target SPL (dB)

Cabinet SPL

(dB, 1m)


Distance (metres)


Cabinets Required



Frequency, Wavelength and Delay

Frequency (Hz) Wavelength (m) Cancellation (m)
Wavelength (m) Frequency (Hz) Cancellation (Hz)
Distance (m) Delay (ms)
Delay (ms) Distance (m) Distance (ft)


Loudspeaker/Amplifier Connections

Combined Impedance

Single Speaker

Impedance (Ω)

Number of



Combined Load (Ω)

Cable Resistance and Damping Factor

Cable Length (m) Core Size (mm2) Load Impedance (Ω) Cable Resistance (Ω)

Damping Factor


Damping Factor


Damping Factor


Damping Factor


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