AUL/AAS Sound & Stage/StagecraftIntro to PAs - Small PA

PAstands forPublic AddressNOT Parents Association, Port Authority or Pennsylvania IN THE PRODUCTION WORLD

Lo-Z Low ImpedanceHi-Z High Impedance

Impedance is a measure of resistance.IN THE PRODUCTION WORLD

EQ stands for EQUALIZE or EQUALIZERAn EQUALIZER allows you to CUT ( - ) or BOOST ( + ) the frequencies of an audio signal IN THE PRODUCTION WORLD

VenueMeans the site, place, location, scene, setting or spot where an event is. The word venue derives from the Latin venire (to come), and implies a place that people come to. IN THE PRODUCTION WORLD

TransducerA transducer is a device, usually that converts one type of energy or physical attribute to another.IN THE PRODUCTION WORLD

ElectroacousticThe conversion of sound into electricity and vice versa, as in a microphone or a speaker. Electro: Electricity + Acoustic: having to do with hearing or with sound as it is heard IN THE PRODUCTION WORLD

i.e. (id est) is a Latin phrase meaning that is"That is (to say)" in the sense of "that means" and "which means", or "in other words", or sometimes "in this case", depending on the context GENERAL KNOWLEDGE

e.g. (exempli gratia ) is a Latin phrase meaning 'for the sake of example' Usually shortened in English to 'for example'. Often confused with id est (i.e.). GENERAL KNOWLEDGE

A public address or "PA" system is an electronic amplification system used to reinforce a given sound, e.g., a person making a speech, prerecorded music, or message, and distributing the sound throughout a venue.

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.

There is some disagreement over when to call these audio systems Sound Reinforcement (SR) systems or PA systems.

Some audio engineers distinguish between the two by technology and capability, while others distinguish by intended use, e.g. SR systems are for live music, while PA systems are usually for reproduction of speech and recorded music in buildings and institutions.

Small 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.

Small systems cont. 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.

Large venue systemsFor popular music concerts, a more powerful and more complicated PA System is used to provide live sound reproduction.

Large venue systems cont.In a concert setting, there are typically two complete PA systems: the "main" system and the "monitor" system. Each system consists of microphones, a mixing board, sound processing equipment, amplifiers, and speakers.

Large venue systems cont.The "main" system (also known as "Front of House", commonly abbreviated FOH), which provides the amplified sound for the audience, will typically use a number of powerful amplifiers driving a range of large, heavy-duty loudspeakers.

Large venue systems cont.A large club may use amplifiers to provide 1000 to 2000 watts of power to the "main" speakers; an outdoor concert may use 10,000 or more watts.

Large venue systems cont.The "monitor" system reproduces the sounds of the performance and directs them towards the onstage performers (typically using wedge-shaped monitor speaker cabinets), to help them to hear the instruments and vocals.

Large venue systems cont.The monitor system in a large club may use amplifiers to provide 500 to 1000 watts of power to the "monitor" speakers; at an outdoor concert, there may be several thousand watts of power going to the monitor system.

Large venue systems cont.At a concert in which live sound reproduction is being used, sound engineers and technicians control the mixing boards for the "main" and "monitor" systems, adjusting the tone, levels, and overall volume of the performance.

Power amplifiersPower amplifiers boost a signal level and provide current to drive a loudspeaker. Generally, an amplifier or simply amp, is any device that changes, usually increases, the amplitude of a signal.

MixerIn professional audio, a mixing console, or audio mixer, also called a board, soundboard, or desk is an electronic device for combining (also called "mixing"), routing, and changing the level, timbre and/or dynamics of audio signals.

Mixer cont.A mixer can mix analog or digital signals, depending on the type of mixer. The modified signals (voltages or digital samples) are summed to produce the combined output signals.

SpeakerA loudspeaker (or "speaker") is an electroacoustic transducer that converts an electrical signal into sound.

Speaker cont.The speaker pulses in accordance with the variations of an electrical signal and causes sound waves to propagate through a medium such as air or water.