For passive speakers, compare the speaker’s RMS power handling with the amplifier’s continuous RMS output per channel at the speaker’s rated impedance, while also accounting for 70V or 100V transformer taps when applicable. A similar amplifier rating is a practical starting point, and a higher-rated amplifier can work when the system uses appropriate gain structure and limiting to manage peaks and prevent clipping.

RMS power describes the speaker’s sustained power-handling or output capability during normal operation, making it a useful figure for matching speakers with amplifiers. Peak power refers to the higher level a speaker may handle briefly during musical or program transients, so it should not be used as the primary basis for continuous system planning.

Choose an RMS power rating based on the speaker’s continuous power handling, amplifier output, room size, listening level, speaker sensitivity, and whether the system serves background audio, paging, foreground music, or live sound. For residential, commercial, and installed audio systems, select speakers and amplification with compatible RMS ratings and reasonable headroom, then account for impedance, low- or high-impedance distribution, coverage, and the installation environment.

For low-impedance speakers, match the amplifier to the speaker’s nominal impedance, such as eight ohms, and select an amplifier RMS output that fits the speaker’s RMS power handling. For 70V or 100V systems, choose the speaker’s transformer tap based on the desired wattage, add the tap settings for all connected speakers, and select an amplifier with suitable capacity for the combined load.