Audio power
| Sound measurements | |
|---|---|
Characteristic | Symbols |
| Sound pressure | p, SPL, LPA |
| Particle velocity | v, SVL |
| Particle displacement | δ |
| Sound intensity | I, SIL |
| Sound power | P, SWL, LWA |
| Sound energy | W |
| Sound energy density | w |
| Sound exposure | E, SEL |
| Acoustic impedance | Z |
| Audio frequency | AF |
| Transmission loss | TL |
Audio power is the electrical power transferred from an audio amplifier to a loudspeaker, measured in watts. The electrical power delivered to the loudspeaker, together with the speaker's efficiency, determines the sound power generated (with the rest of the electrical power being converted to heat).
Amplifiers are limited in the electrical power they can output, while loudspeakers are limited in the electrical power they can convert to sound power without being damaged or distorting the audio signal. These limits, or power ratings, are important to consumers in finding compatible products and comparing competitors.