Difference between rms and PMPO

[electronics_shamim]

Sirs,

Can anyone clarify the difference between rms value and pmpo calculation, with respect to audio amplifier ICs. ICs datasheet shows 4.5w, whereas the pmpo is written as 40watt. Is it the 10x times of rms?

regards,
shamim
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[audioguru2]

Hi Shamin,
The power rating of an audio amplifier is supposed to be with its built-in power supply (if it has one, or its supply voltage should be mentioned), all channels operating continuously with a sine-wave from 20Hz to 20kHz and at low distortion below clipping. The power rated will be continuous RMS power at low distortion at any audible frequency per channel.

But the marketing guys lie about power:
1) Peak (or also called maximum) power is simply the power number doubled.
2) Music Power is only for a moment before the power supply voltage sags or before something gets too hot and melts.
3) They turn up the volume way too high so the clipped extra output is harmonics from severe distortion.
4) They use a load resistance that is way too low so the instantaneous current (and power) is much higher.

A 4-channel car amplifier is rated at 200W. It is actually only 15W per channel.

 

[electronics_shamim]

Sir,

Thanks for the guidance on the above.  Hope to get similar co-operation in future.

regards,
shamim
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[ben23]

basically

PMPO is bullshit
RMS is what u should be looking at