Speaker Amplifier Matching Calculator

This tool calculates the Amplifier (or Amp) Output Power (Watt) required to provide a specified Sound Pressure Level (SPL) at a distance away from the speaker.

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  • Speaker sensitivity (1W/m) in dB
  • Amplifier Headroom (in dB)
  • Distance from the speaker (in feet or meters)
  • Target Sound Pressure Level (dB) at this distance



Example Calculation

As an example let’s design an audio system where

  • The listening position is 50 feet (or 15.2 meters) away from the speaker
  • The desired Sound Pressure Level is 95 dB SPL

The speaker chosen for the job has a sensitivity rating of 85 dB. Apply a minimum recommended amplifier headroom of 3 dB.

According to the calculator, an amplifier that can supply at least 4634 watts to the loudspeaker is required.

What is speaker sensitivity?

Sensitivity measures how well power input to the speaker is converted to sound energy.

As an example, the sensitivity of a speaker might be rated as 90 dB (1W/1m). This means that speaker produces a level of 90 dB when driven with an amplifier that provides 1 Watt of power. The measurement is made 1 meter in front of the speaker.

The higher the number in dB, the more sensitive the speaker and the more efficient it is in converting the power output of an amplifier to audio.

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