WHAT IS PUBLIC ADDRESS SYSTEM ?
Public address system are used in public venues that requires announcer, performer etc. Public address system is a system that is ready with four channel component. Four components are Microphone, Mixer, Amplifier and Loudspeaker.
First component of public address system is microphone, which is mainly transducer. It coverts acoustic energy to electrical energy. It converts the sound into voltage.
There are two types of Microphone.
1. Wired Microphone
2. Wireless Microphone
Wired- Wired microphone is used for places where there are so many obstacles are in between announcer and performer like schools, Factories, in public place etc.
Wireless-Wireless microphone are used mostly for Indore premises. Like for auditorium, Office and Small event in public place, conference hall etc.
Second Component is mixer machine. The Mixer is an important equipment of the public address system. It is used to control many sound sources simultaneously. Manage all incoming sound in form of voltage signal from microphone and give signal to amplifier.
Third component is of system is Amplifier. The amplifier is device which controls the sound level of loudspeaker. In advance amplifiers mixer is inbuilt to reduce bulky system and cabling work .It is a two port electronic circuit uses electric power from a power supply to increase the amplitude of a signal applied to its input terminals. Gain is a factor value, which shows the amplification done by amplifier. Gain is nothing but the ratio of output voltage or current or power to the input.
Fourth Component is loudspeaker. Loudspeaker is a transducer .it is convert electrical energy to acoustic energy. The sound level of speaker is always higher than the sound level of the source.
Public address system used to allows a person to address large public from one centralized location. Example for announcements of movements at large and noisy area. It is used in small venues such as school, churches, and small bar.
HOW PUBLIC ADDRESS SYSTEM WORKS ?
Public address system is an electronic system which consists of microphones, amplifiers, loudspeakers, and Mixer.
PA system is used to amplify the apparent loudness of a human voice, or musical instrument, or other acoustic sound source or recorded sound or music. This system is used in any public where announcer is required to control performer or audience or mass people, etc. PA system is used at places like public transportation, sports stadiums, and
Other facilities, at live or recorded music venues and events also it is used. A PA system may set of multiple mics or sound sources, a mixing console that mixes and modify multiple sources, and different amplifiers and loudspeakers for louder volume for wider distribution.
Two types of cable used to connect microphone to mixer or amplifier
XLR connector’s cable- XLR connector’s cable is electrical connectors for professional audio and video and stage lighting equipment. Connectors are circular in design between three and seven pins.
TRS connectors cable- An electronics devices such as digital cameras, camcorders, and portable DVD players use 3.5 mm connectors for composite video and audio output. Connection which used for mono unbalanced audio plus video is TRS ,and a TRRS connection for stereo unbalanced audio plus video.
MIXER- The Mixer is the core of public address system. Most important part of mixer is its processing decision, Grain structure control, channel EQ and mix. The channel gain control adjusts the level of the signal in that channel so that it is for the mixer’s circuitry. Some mixers also have a Pad switch, to reduce the level of signals that are too big when they arrive.
Equalizer modes –
- High and Low (fixed frequency)
- High, Mid and Low (fixed frequency)
- High and Low fixed frequency, variable frequency (‘sweepable’or ‘semi-parametric’) Mid
- High and Low fixed frequency, two variable frequency (‘sweepable’or ‘semi-parametric’) Mids
- High and Low fixed frequency, two variable frequency and variable bandwidth (‘fully parametric’) Mids. Four-section fully parametric EQ
The most widely used type of speaker is the dynamic speaker. The dynamic speaker operates on the same basic principle as a dynamic microphone. Speakers are typically housed in a speaker enclosure or speaker cabinet which is often a rectangular square box made of several forms of wood, or sometimes plastic.
There are four types of loudspeaker
- Woofer (low frequency) uses in phone (mobile).
- Sub-woofer (low frequency).
- Squawker (medium frequency)
- Tweeter (high frequency) uses in cinema mall.
WHY TO USES PUBLIC ADDRESS SYSTEM ?
To increase intensity of sound so that it can reach to maximum distance, we cannot use direct microphone and speakers to do so. Hence PA system is used.
If there is any event in a public place, then it is necessary to have a public address system, because public address system has ability to reduce the surrounding noise and create crystal clear sound for audience.
For organising large events in public Places.
In situation where incidents like fire, kayos or any riot happen in any institution or public places then to announce this alert to other people in same vicinity PA System is useful.
Now days in smart city projects PA Systems are designed for two way communication so that performer can commute to announcer who is in control room.
Type of PA Systems,
- Small systems. The simplest, PA systems including a microphone, an amplifier, and one or multiple loudspeakers. …
- Large systems. …
- PA over IP. …
- Long line PA. …
WHERE TO USES PUBLIC ADDRESS SYSTEM
– School auditorium
-industrial area
-Railway station
-Airport
-public meeting
-Political events
-Malls & Multiplexes
