What is the difference between the "RMS" value and"PMPO"value in audio or sound systems or in general speakers

Answer 1

RMS (Root Mean Square) is the actual rating of an amplifier (or speakers), meaning, it is the realistic value. A 120 watt per channel RMS is already monstrous. PMPO (Peak Music Power Output), on the other hand, is the PEAK, meaning this is the highest wattage it can reach but for a very split second only, in short bursts. Usually, PMPO is used by manufacturers who try to fool their customers by claiming their product is so powerful. These are commonly found on boom boxes because boom boxes are bought mostly by average household listeners, and putting such figures may entice an average buyer. They don't use these for real home theater machines where buyers understand. Imagine, a 5-channel boombox with 70-watt (PER CHANNEL) may be labeled as 3000 watts total PMPO (That is the PEAK power for ALL channels combined).

Also remember, a higher wattage doesn't always translate to good sound output. There are dozens of specs that can influence a good audio.

So don't use this as your basis in buying. Listen to the product...that's what matters most.

Answer 2

What is often called RMS is actually continuous power; the amount of power that an amplifier will put out over a period of time. For this spec to be valid, you need to know the frequency or frequency range over which it is measured and the amount of distortion.

Peak Music Power is a number that the manufacturer grabs out of thin air. Supposedly, it represents the power that the amp will put out (or a speaker will accept) for a quick burst of sound like a drumbeat. This spec is meaningless and should not be used as an indication of any kind of quality.

Reputable manufacturers do not provide PMP specs.

Answer 3

See this http://en.wikipedia.org/wiki/PMPO

PMPO is a marketing gimmick that boost the apparent power spec of the amp. "RMS" represents the real power delivering capability of an amp, and should be rated over the full frequency range.