PMPO is a poor measure of amplifier power output. It is a mostly arbitrary figure that can be easily manipulated to make an amplifier look better on paper than it really is. Always use RMS power (continuous power) when judging the power output of an amplifier.MPO is different than peak power (music power). Peak power is related to RMS power by an amplifier's headroom (dynamic headroom). A headroom of 3dB indicates a doubling of continuous power, so an amp with 3dB of headroom and a continuous (RMS) power rating of 100 watts could produce 200 watts of peak power. If its headroom were 6dB, it could produce 400 watts of peak power. Note, however, that most quality amplifiers do not have headroom values of greater than 3dB. A higher headroom value typically indicates a poor power supply that cannot provide sufficient power at normal levels of output.he PMPO term is not a reliable measure of amplifier performance.