Public address system

A public address system (or PA system) is an electronic system comprising microphones, amplifiers, loudspeakers, and related equipment. It increases the apparent volume (loudness) of a human voice, musical instrument, or other acoustic sound source or recorded sound or music. PA systems are used in any public venue that requires that an announcer, performer, etc. be sufficiently audible at a distance or over a large area. Typical applications include sports stadiums, public transportation vehicles and facilities, and live or recorded music venues and events. A PA system may include multiple microphones or other sound sources, a mixing console to combine and modify multiple sources, and multiple amplifiers and loudspeakers for louder volume or wider distribution.

Horn loudspeakers are often used to broadcast sound in outdoor locations.
Rear panel of a medium sized PA system, positioned at one side of the stage at a concert of the musical group Dead Can Dance in 2022, the size being about 3 m from left to right. The setup includes the mixing console for the sound engineer (operating interface with slide controls etc. on the rear) and also the power amplifiers with loudspeaker cables, not in the picture are only the loudspeaker systems distributed around the stage.

Simple PA systems are often used in small venues such as school auditoriums, churches, and small bars. PA systems with many speakers are widely used to make announcements in public, institutional and commercial buildings and locations—such as schools, stadiums, and passenger vessels and aircraft. Intercom systems, installed in many buildings, have both speakers throughout a building, and microphones in many rooms so occupants can respond to announcements. PA and Intercom systems are commonly used as part of an emergency communication system.

The term sound reinforcement system generally means a PA system used specifically for live music or other performances.[1] In Britain any PA system is sometimes colloquially referred to as a Tannoy, after the company of that name, now owned by TC Electronic Group, which supplied many of the PA systems used previously in Britain.[2]


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This article uses material from the Wikipedia article Public address system, and is written by contributors. Text is available under a CC BY-SA 4.0 International License; additional terms may apply. Images, videos and audio are available under their respective licenses.