Use this calculator to find the maximum peak Sound Pressure Level (SPL) of a speaker.
- Sensitivity of the speaker (typically measured at 1m)
- Peak rating of the speaker (Watt)
SPLMax = Sensitivity + 10*Log10(PS/PD)
- Sensitivity is the level in dB produced by the speaker when it is driven with 1 watt of amplifier power. It is measured at a distance of 1 meter in front of the speaker
- PS= Peak rating in watts
- PD= Rating in watts at which sensitivity is specified. (This number is usually 1W)
A speaker has a sensitivity rating of 90 dB. This is based on a measurement made at 1 meter from the speaker, with a 1 Watt amplifier input to the speaker. It also has a peak rating of 500 Watt.
Using the calculator, the speaker’s Maximum Sound Pressure Level is 117 dB.
 Yamaha article on calculating Max SPL