My Boom Box or home Hi-Fi says it is 500 watts, why does it sound so ordinary when I use it at a party?
Quite a lot of people have rung us and said something like… “We had a party and we used our own hi-fi system because it’s 500 watts, and that’s loud I think, but it didn’t sound all that good”.
Well, that is very often the case, and there are several reasons why most home audio gear doesn’t perform all that well when worked really hard. However let’s concentrate on the watts issue first. There are three different ways amplifiers and speakers can be rated. Watts RMS (Root Mean Square), Watts PMP (Peak Music Power) and Watts Peak Transient Load.
Because marketers will be marketers, it is most likely your 500 watt hi-fi system is 500 watts PMP, not RMS. Some brands (no names-no pack drill) may even have marketed a system claiming 500 watts peak transient load.
Well, unless you are an electronics head you are probably just as much in the dark after reading that paragraph as when you started; so lets explain the differences between these power ratings.
Maximum watts RMS: This is the TRUE maximum power level the amplifier/speakers can deliver constantly. As a rule of thumb this is about HALF of watts PMP! So your 500 watt system may be in truth be only capable of delivering approx 250 watts constantly.
Watts PMP: This is the maximum amount of power delivered in the form of a short controlled burst of high power signal that the amplifier and or speakers will tolerate for a short time without doing damage. Usually this is around TWICE the RMS wattage of a system.
Peak transient load is the “abuse” a speaker/amplifier system will tolerate for a few milliseconds without blowing up!