RMS and Peak power are ratings used to determine the overall performance of home audio products, such as speakers, subwoofers, and amplifiers. This article is an overview of how these ratings work and are applied.
RMS Power referers to Root-Means-Square power. The formula for determining RMS power is 70.7 x Peak Power Rating. The RMS power rating is a measure of continuous power measured in watts and the higher the RMS power means the device is either able to provide or accept the specified power over a significant length of time without fail.
Many suppliers use the PEAK POWER ratings in their specifications. We do not recommend the use of Peak Power ratings when assessing the capabilities of a music product because Peak Power does not reflect a product's capabilities under normal, every day use. It is simply a measure of how much power can be generated of handled for a very short period of time. Speakers, subwoofers and amplifiers should be compared using the RMS power ratings to ensure that the right product is chosen for the application in question.
As an example, if a speaker has a RMS wattage rating of 100 watts and a connected amplifier has a RMS wattage rating of 100 watts, the speaker should theoretically, be a perfect match regarding power capabilities and result in optimum performance from both products. Most importantly do not be fooled by "Peaker Power" or the erroneous numbers often made up by the supplier. Only true power, under everyday, realistic circumstances actually means anything.