PMPO versus RMS

Root mean square (also known as RMS) is a measurement used to acquire the output values of the Power Outputs. It is also known as the most accurate way of garnering these measurements. The RMS is also known as the quadratic mean. In this case, it is used to measure amplifier power. It is used in conjunction with the electric efficiency of an electronic amplifier, and is a way to measure the ratio of mean (or average) output power to mean (or average) output power.

Peak music power output (or PMPO) is a term that is used mostly to advertise the quality of sound that is expelled from amplifiers. It is not quite a defined term; however, it is thought to be the sum of the peak power that the amplifiers use in any sound system. As it is a loosely based term and has not been concretely defined, the definition changes often, as does the ratio of PMPO to the continuous power output. The PMPO can at best be estimated by taking a look at the input current.

Simply put, the RMS, square root of the average of the squares of a set of values – are based on a continuous time waveform. As a quadratic equation, it takes the following form:

xrms=x12+x22+…+xn2n 

There are several permutations therein that define the RMS for waveforms, a function over all time, electrical power, and amplifier power efficiency

PMPO is not to be confused with peak momentary power output (which shares the same acronym). They have two separate specifications, and are therefore measured differently. As such, the two cannot be transferred between each other, i.e. you cannot convert peak music power output to peak momentary power output. Regarding those professionals in the field, the term is meaningless, and ultimately confusing, when defining the power of an amplifier. PMPO can only be sustained for a short period of time without causing serious – and in some cases irreparable – damage to an amplifier.

RMS is used very effectively in calculations of power (such as voltages found on power outlets). As a result of their versatility, peak values are also calculated using RMS, and signal outputs can also be calculated using the RMS of the above equation.

Summary:

1. RMS is used to acquire the output values of Power Outputs; PMPO is a widely used term for advertisement