A public address system (PA system) is a sound amplification system used to allow a person or persons to address an audience at a greater volume than would be possible or practicable without such a system. At a minimum, such a system comprises a microphone, an amplifier and a loudspeaker. Examples of content include announcements and other audio material at sports stadiums, air and rail terminals, and the sound produced by a singer, musician or musical ensemble, as well as recorded music. A PA system may include multiple microphones and/or other sound sources, a mixing console to combine and modify multiple sources, and multiple amplifiers and loudspeakers for louder volume, greater coverage and/or wider distribution, such as that required to provide sound throughout an entertainment venue, an office building or retail space, or an outdoor environment.A public address or “PA” system is an electronic amplification system with a mixer, amplifier and loudspeakers, used to reinforce a given sound, e.g., a person making a speech, prerecorded music, or message, and distributing the sound to the general public around a building.