Small PA systems

The simplest PA systems consist of a microphone, a modestly-powered mixer-amplifier (which incorporates a mixer and an amplifier in a single cabinet) and one or more loudspeakers. Simple PA systems of this type, often providing 50 to 200 watts of power, are often used in small venues such as school auditoriums, churches, and small bars.

In North America, PA systems are also sometimes referred to as "sound reinforcement systems" or simply "sound systems." In colloquial English, a PA system installed for public address in a building is sometimes referred to as a "Tannoy" system after the company of that name. Compact Oxford English Dictionary "Tannoy": http://www.askoxford.com/concise_oed/tannoy?view=uk

Public address systems typically consist of input sources, preamplifiers and/or signal routers, amplifiers, control and monitoring equipment, and loudspeakers. Input sources refer to the microphones and CD Players that provide a sound input for the system. These input sources are fed into the preamplifiers and signal routers that determine the zones to which the audio signal is fed. The preamplified signals are then passed into the amplifiers. Depending on a countries' regulation these amplifiers may amplify the audio signals to 50V, 70V or 100V speaker line level. Control equipment monitors the amplifiers and speaker lines for faults before it reaches the loudspeakers.

Taken from the WikiPedia article on Public Address. There is further extensive detail in the wikipedia entry.

External Links

• Source Wikipedia article on Public Address