PA System Calculations

Calculating Some Commonly-Used Sound System Values

You can also find tools for frequency calculations on the page dealing with Parametric EQ in the Equipment Guide.

To calculate and display the variable in the right-hand field of any row, enter values in the left-hand field(s.

These functions use JavaScript. They will work in most up-to-date browsers as long as JavaScript is enabled.


Signal and Power Levels


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


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


Loudspeaker 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)
SPL @ 1 metre (dB) Target SPL Range (metres)


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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