Public Address System

A public addressing system (PA) consists of certain electronic devices such as microphones, loudspeakers, amplifiers, console and other acoustic sound sources which are used to produce sound or send messages in a noisy environment. Public addressing systems are usually employed in public venues where civilians or people gather in large groups. Important announcements or updates are communicated through public addressing systems in places like stadiums, prayer halls, railway stations, metro stations, subways, airplanes, and other relevant places. The best application of public address systems is for emergency communication or to pass updates during an emergency. The major constituents of Public addressing systems are Speakers and Amplifiers. Public Address systems are also called as sound reinforcement systems where a couple of acoustic sound sources are paired for the purpose of producing a sound of high quality. These devices further assist in amplification and distribution on soundwaves which are captured from a source these are mostly used for alerting people during an emergency. The key features of each of the following devices are as follows

Speakers

A loudspeaker is an electronic device that works as an acoustic transducer that captures electronic audio signals from a source and further amplifies them into sound. Public address system speakers are usually conical-shaped devices and are widely used in a dynamic environment. Besides these, there are also rectangular enclosures of speakers that are used for reproducing high audio frequencies called tweeters. Dynamic loudspeakers are usually for emergency communication or to alert people of large noisy groups. The quality of sound largely depends on the kind of materials used to build the frame of the speakers or the body of the speaker.

Amplifiers

Amplifiers or amps are devices used to strengthen voltages or power of signals. There are two major types of amplifiers, weak signal amplifiers or power amplifiers. Power amplifiers are usually used in sound reinforcement systems to amplify audio signals to a high-quality sound. Amplifiers are connected to speakers which become the final source for producing sound. Public address systems altogether are used in areas like stadiums, railway stations, metro stations, schools, prayer halls, industrial premises, and other similar places to make important announcements or for emergency communication. Public address speakers or amplifiers also are of high importance in the field of defense which are used for communication to people or fellow officers during emergency call outs.

Microphones

Every Public Address System needs Microphones. There are basically two categories of microphones; The Condenser and Dynamic.

Condenser mics generally work on phantom power and would require mixers with sufficient built-in phantom-powered inputs. They are made to capture more intricacies and are used to handle high sound pressure levels. They are usually for live sound and recording. Condenser mics phantom power can also be delivered from other sources like mic cable, mic preamp, or from a standalone phantom power device.

Dynamic mics provide multi-pattern function by netting sounds from different directions. Dynamic mics are long-lasting, reliable, and are made for onstage use. While condenser mics are good for high frequencies also note that they are prone to breakage, which is a downside to their usage. Other kinds of microphones include the wired and wireless microphones.

Mixers

A mixer allows for multiple input of audio signals and equalizes them for broadcast at different levels. If a microphone or another acoustic source is used in a Public Address system, it is plugged into a mixer. A professional level mixer will have multiple inputs to accommodate lots of microphones while a simple mixer will only allow few inputs. There different types of mixers depending on what’s suitable for you; Digital mixers (They use digital signal processing technology), Analog mixers (for adjusting volume and tone of input audio signals) and Powered mixers (Powered mixers are analog mixers with built-in power amplifiers).