Audio Power - Peak Power

Peak power is the maximum level of work or energy output that is measured during an observation period. Peak power here refers to the maximum amount of power an electronic component can possibly handle for an instant without damage. Because of the highly dynamic nature of many audio signals (e.g., music, which accounts for an alternative name, music power) there is some sense in attempting to characterize the ability of equipment to handle quickly changing power levels. But, how small an instant is a matter of some variation from observer to observer and so a peak power rating is necessarily more than a little indeterminate.

It always produces a higher value than the continuous ("RMS") figure, however, and so has been tempting to use in advertising. Generally, whatever the definition of instant used, distortion is also higher for an instant. For instance, an amplifier (especially a surround sound receiver), may be rated at 1,000 watts peak power, but the harmonic distortion level might be 10 percent under those conditions. Peak power is also referred to as max power or PMPO (Peak Music Power Output). It is often five or six times greater than the continuous ("RMS") rating.

Ambiguity: Among amplifiers, the peak power rating is fairly ambiguous as it varies depending on "acceptable" maximum harmonic distortion. For example, the peak power output rating of surround sound receivers is often taken at 10 percent THD. The highest generally acceptable level of total harmonic distortion is considered to be 0.1%. Hence, two max power output ratings are sometimes provided, one at 0.1% THD, and another at 10% THD.