When choosing an amplifier, it is important to understand the different power ratings that are used to measure amplifier output. There are three main types of power ratings: RMS, peak, and IPP.
- RMS (root mean square) power is the most accurate measure of an amplifier’s output power. It is measured by applying a continuous signal to the amplifier and measuring the average power over a period of time. RMS power is the most relevant power rating for most applications.
- Peak power is the maximum amount of power that an amplifier can output for a short period of time. Peak power is often used in marketing materials to make amplifiers seem more powerful than they actually are. Peak power is not as relevant as RMS power for most applications.
- IPP (instantaneous peak power) is the maximum amount of power that an amplifier can output for an infinitesimally short period of time. IPP is even less relevant than peak power for most applications.
In addition to the three main power ratings, there are a few other power ratings that are sometimes used. These include:
- THD (total harmonic distortion) is a measure of the amount of distortion in an amplifier’s output signal. Distortion is any unwanted signal that is added to the amplifier’s output signal. THD is measured in percent. A lower THD value is better.
- SNR (signal-to-noise ratio) is a measure of the amount of noise in an amplifier’s output signal. Noise is any unwanted signal that is added to the amplifier’s output signal. SNR is measured in decibels. A higher SNR value is better.
When choosing an amplifier, it is important to consider all of the relevant power ratings and specifications. The most important factors to consider are the type of speakers you will be using, the size of the room you will be using the amplifier in, and the type of music you will be listening to.
Here are some general guidelines for choosing an amplifier:
- For small speakers in a small room, a 50-watt amplifier will be sufficient for most listening needs.
- For medium-sized speakers in a medium-sized room, a 100-watt amplifier will be sufficient for most listening needs.
- For large speakers in a large room, a 150-watt or more amplifier will be needed for most listening needs.