An Introduction to PA (Public Address) system

Written & Edited by : Mohammed Zaid Shaikh+97152-5953641

Public Address System

A public address system : (PA system) is an electronic sound amplification and distribution system with a microphone, amplifier and loudspeakers, used to allow a person to address a large public.The term is also used for systems which may additionally have a mixing console, and amplifiers and loudspeakers suitable for music as well as speech, used to reinforce a sound source, such as recorded music or a person giving a speech or distributing the sound throughout a venue or building.

Public Address System

Public Address System : (Definition :1)

Public Address System

What is a PA System?A “Public Address” system is anything that amplifies sound so more people can hear it. The most basic example might be a megaphone, or single microphone and speaker, used to make someone’s voice louder. Public address systems consist of input sources, amplifiers, control and monitoring equipment, and loudspeakers. The primary input sources are microphones for live announcements and a source of recorded sound.

Public Address System : : (Definition :2)

Public Address System

There may be a system which allows operators, or automated equipment, to select from a number of standard prerecorded messages. These input sources are fed into 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 local practices these amplifiers will usually 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. This control equipment is also used for separating zones in a PA system. The loudspeaker is used to convert electrical signals into sound.

Public Address System : Microphone

A Microphone :(colloquially called a mic or mike; both pronounced /ˈmaɪk/) is an acoustic-to-electric transducer or sensor that converts sound into an electrical signal. Microphones are used in many applications such as telephones, tape recorders, hearing aids, motion picture production, live and recorded audio engineering, FRS radios, megaphones, in radio and television broadcasting and in computers for recording voice, speech recognition, VoIP, and for non-acoustic purposes such as ultrasonic checking or knock sensors..

Public Address System : Mixer

MixerThere have been two conventional categories of live sound mixers for quite awhile: powered and unpowered analog mixers. Now there is also a new generation of digital consoles designed for studio and live sound applications that bring the added benefits of total recall mixing and onboard effects.

Powered Mixers

Digital Mixers

Public Address System : Amplifiers

Amplifiers

AmplifiersAn Amplifier: is a device for increasing the power of a signal by use of an external energy source.

In an electronic amplifier, the input "signal" is usually a voltage or a current.

Other types exist; a fluidic amplifier increases the power of signals represented as flow of gas or liquid, for example. Amplifiers may be classified in a variety of ways depending on their application, the frequency range they cover, or the active devices used. Ideally an amplifier increases the power of a signal without otherwise altering it; practical amplifiers have finite distortion and noise which they invariably add to the signal.

Public Address System : Loudspeaker

Loudspeaker

A Loudspeaker (or "speaker") is an Electroacoustic transducer that produces sound in response to an electrical audio signal input. Non-electrical loudspeakers were developed as accessories to telephone systems, but electronic amplification by vacuum tube made loudspeakers more generally useful. The most common form of loudspeaker uses a paper cone supporting a voice coil electromagnet acting on a permanent magnet, but many other types exist. Where accurate reproduction of sound is required, multiple loudspeakers may be used, each reproducing a part of the audible frequency range. Miniature loudspeakers are found in devices such as radio and TV receivers, and many forms of music players. Larger loudspeaker systems are used for music, sound reinforcement in theatres and concerts, and in public address systems.

Public Address System

Wired in PA System

Wired in PA System :A public address system (PA system) is an electronic amplification system with a mixer, amplifier and loudspeakers, used to reinforce a sound source, e.g., a person giving a speech, a DJ playing pre-recorded music, and distributing the sound throughout a venue or building.

Public Address System

Wireless Public Address and Intercom Solutions

Wireless Public Address and Intercom Solutions :Public address & intercom line of products, offers an easy and economical way to incorporate a two-way Public Address system for daily and emergency announcements throughout any type of facility. College campuses, schools, medical centers, office buildings, manufacturing plants, military bases and other facilities.

Public Address System : Distribution Amplifier

Distribution Amplifiers : A complete range of distribution amplifiers are made by Precision Test Systems.  A distribution amplifier is used to distribute the output of a frequency reference to many different places.  Usually the frequency is 5 or 10 MHz.In electronics, a distribution amplifier or simply distribution amp, is a device that accepts a single input signal and provides this same signal to multiple isolated outputs.These devices are important because they allow a signal to be distributed to multiple destinations without ground loops or signal degradation. They are used for a number of common engineering tasks, including multiple amplification, cable television, splitting monitor and front of house mixes, and "tapping" a signal prior to sending it through effects units to preserve a "dry" signal for later experimentation.Distribution Amplifier Delivers Full HD Output to 4 Displays.

Public Address System : Audio Power Amplifier

Audio Power Amplifier

An audio power amplifier is an electronic amplifier that amplifies low-power audio signals (signals composed primarily of frequencies between 20 - 20 000 Hz, the human range of hearing) to a level suitable for driving loudspeakers and is the final stage in a typical audio playback chain.The preceding stages in such a chain are low power audio amplifiers which perform tasks like pre-amplification, equalization, tone control, mixing/effects, or audio sources like record players, CD players, and cassette players. Most audio power amplifiers require these low-level inputs to adhere to line levels.While the input signal to an audio power amplifier may measure only a few hundred microwatts, its output may be tens, hundreds, or thousands of watts.

Public Address System8 Steps to building your first PA system

If you've ever thought to yourself, "What do I need to put together a PA system?", you've come to the right place! While there is a lot to know about sound reinforcement, this article is meant to give you some basics regarding the various components of a live sound system - just enough to get you pointed in the right direction. There is a TON of additional information in the Live Sound Buying Guides, a LOAD of live sound equipment to choose from online right at Sweetwater, and we welcome your phone call at 1-800-222-4700 where you can speak with someone who understands the ins and outs of live sound and can further answer your questions.Just about every live sound system (or"PA" system) is comprised of the following basic components. Just follow this step-by-step guide and you'll find that building your own system is completely within reach.

Public Address SystemStep – 3 : Choose Appropriate PA Speakers

Choose Appropriate PA SpeakersPA speakers can be active (powered) or passive (unpowered). "Active" means that the speakers have amplifiers built in, which provides the advantage of not having to buy, carry, and match speaker to a power amp. Conversely, passive speakers do not have built-in amplification, but they come in a wide variety of configurations, generally have a much higher power capacity, and can be convenient if you already own power amps. Beyond choosing powered or unpowered, there are a number of other factors to consider, such as bi-amped, tri-amped, and whether or not to add a subwoofer to your system.

Public Address SystemStep – 4 : Pick Out the Right Monitor System

Pick Out the Right Monitor SystemYour vocalist will be more likely to sing in key, your bass and drummer will be more likely to play in the pocket, and your lead guitar player will know when to stop playing licks IF they can all hear what's going on. There are more options today for stage monitoring than ever before. You can go with traditional unpowered stage wedges, in-ear monitoring systems (wired or wireless), smaller stage fills, and/or powered solutions. Wireless Monitor System ...

Wired Monitor System ...

Public Address SystemStep – 5 : Get the Right Power Amplification

Get the Right Power AmplificationIf you're going with a powered mixer or powered speaker system, then you might not need outboard amps at all. However, if you need to match a power amp to a PA speaker, a general rule of thumb is to pick an amplifier that can deliver power equal to twice the speaker's continuous IEC power rating. This will allow for extra headroom offering clean, undistorted power.

Stereo Audio Power Amplifier

Public Address SystemStep – 6 : Add Signal Processing

Add Signal ProcessingSignal processing (effects) for live sound usually involves reverb and delay, EQ (graphic or parametric), and compression and limiting. It is important to choose an effects processor that is optimized for live performance. Like powered mixers, effects processing is another area where all-in-one products like the DriveRack PA by dbx are simplifying and greatly improving the quality of live sound.

Public Address SystemStep – 7 : Cable up Your Rig

Cable up Your RigOften overlooked (until you actually try to get sound out of your live sound rig that is), good cables and proper cable management will mean the difference between your audience getting to hear your music or not. Because cables tend to be abused in live performance situations, we strongly suggest solid cables that will last. To begin with, you'll need enough microphone cables to handle your mic setup, plus line or speaker cables to run from your mixer to the speakers.

Public Address SystemStep – 8 : Rack Up and Pack Up Your Equipment

Rack Up and Pack Up Your EquipmentWhether you're planning to gig out live by yourself at your favorite coffee house, or on a national tour with a ten-piece band, keeping your gear and other sound "stuff" organized in properly constructed racks and cases will allow you to set up and take down quickly and let's face it, your investments will last a lot longer than if you lugged it all around in your father's old suitcases. If you plan on going out on the road, a wood-constructed hard case rack is what your rack mount gear will need, but for those of us playing out around town, the molded plastic style portable racks suffice nicely. Be sure to plan for the future. Try to purchase a rack that allows for room to grow.

Rack Up Equipment

Rack Up Equipment

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