I have been asked a few times "why so much power" Here is the answer from the Crown web site.
"Because music has transient peaks that are 6 to 25 dB above the average level, the power amplifier needs to produce enough power to handle those peaks without distortion.
For example, if you need 100 watts continuous power to achieve the desired average SPL, you need 1,000 watts continuous to handle 10 dB peaks, 3,162 watts to handle 15 dB peaks, and 10,000 watts to handle 20 dB peaks. Clearly, the peaks require far more power than the average levels. In the calculator's Peak Headroom field, enter 6 dB for rock music that is compressed or limited, or enter 20 to 25 dB for uncompressed live music. If you can live with some short-term clipping which may be inaudible, enter 10 to 15 dB"
Now 100 watts of continuous power is a lot, so just take one digit off of the example = 10 Continuous watts of power needs, 100 watts for 10 db peaks, 316 watts for 15 db peaks and 1000 watts for 20 db peaks.
Kind regards,
Guy