RMS v/s PMPO

Okay, so how many of you have been to a shop to buy that much awaited Music System but got confused at the last moment by the dazzling numbers on wattage (Yeah, curse that..).

Well, lets get versed with the acronyms  first.

RMS means Root Mean Square.

PMPO stands for Peak Momentary Power Output.

RMS, as the name suggests is the is the average power output of the speaker over a long period of time.

While, PMPO is the maximum power achieved for a speaker under perfect conditions.

RMS is derived from an equation which produces the most mathematically accurate measure of a speaker's power output. The RMS value is often seen listed as "wattsRMS" on product packaging.  An RMS power value is referred to as the real music power output of the speaker. It is a true indication of the output power of a given speaker across its range of pick up frequencies.

On the other hand, PMPO is the term, which is more often used as a marketing ploy. This is because the conditions under which the PMPO is achieved is next to impossible, plus the wattage that comes out at PMPO is only peak. You cannot drive your equipment at continuously that much power (who would really drive their home theatre at 3000W or 6000W).

And yes, there is no particular formula on how to convert PMPO to RMS or vice-versa.  PMPO is the ability to deliver a particularly large amount of power for a fraction of a second. This depends on the individual amp design & depends largely on the size of the filter caps.

Being cleared on this, next time you visit a store for music equipments, you are now more well informed about the product details. So don let that sales person get to you ;)