is there peak power for amps ?

[tank]

I just wanted to now if there is peak power for amps like for speaker? and if yes is there an average of the peak power vs rms power. i will buy speakers of 300 w rms and 800w peak, and i'm looking between 2 amps a 300w rms or a 500w rms. thanks

[cmchamp]

I believe that amps are rated differently than speakers. If an amp says 300w @ 8?, then it's 300w @ 8?, and there's no 'peak' above that. If your speaker handles 800w peak at 8?, you want to drive it with at least an 800w amp, if not a 900w as I believe you want a bit extra just for dynamic overhead.

[DAS]

It depends on what is meant in context by peak. RMS is, by definition, .707 of peak. In other words, If peak power is 100 watts, then the RMS value is 70.7. Conversely, if the RMS value is 100, then peak is (100 x 1.414) 141.4. This is true of a single sine wave, before you even begin to think about the dynamic range of music signals.

Every amp has a peak amount of power it can put out, just as every speaker has a peak amount of power it can handle. Nailing down exactly what this is, however, is very tricky. So these specs are always a little vague. The general rule of thumb is to try to use amps that are rated at roughly twice the power handling ability of the speaker. This gives you 3 dB of headroom for clean amp power beyond the maximum of where you should operate the speaker. The purpose of this is largely to make sure the power going to the speaker is undistorted (or clipped). Clipping amps is the cause of far more speaker destruction than overpowering.