Speaker Power Calculator — Required Amplifier Wattage

For small venues (50 people): 200-500W. Medium venues (200 people): 500-2000W. Large venues (500+): 2000-10000W+. These are rough guidelines — the actual requirement depends on speaker sensitivity, distance, room acoustics and desired SPL.

The calculation gives the minimum continuous power. Music has peaks 6-20 dB above average level. You need headroom (typically 6-10 dB) to handle these peaks cleanly. Under-powered amplifiers clip, producing harsh distortion that can damage tweeters.

Sensitivity (dB SPL at 1W/1m) tells you how loud a speaker is per watt of power. Typical PA speakers are 95-100 dB. High-efficiency horn-loaded speakers can reach 105-110 dB. Every 3 dB more sensitivity halves the required amplifier power.

A common recommendation is to use an amplifier rated at 1.5-2 times the speaker continuous power rating. This provides headroom for peaks. Under-powering is more dangerous than over-powering because clipping produces damaging harmonics.