An Introduction To PA Systems

You must have heard the announcements being made on a railway station or an airport. These announcements are made using PA systems. PA systems (Public Address Systems) are special audio systems which allow a message to be communicated to a large number of people who are present at a certain place.

PA systems are made of four basic components - the microphone, the audio mixer, an amplification device and loud speakers. Each of these is integral part and the PA systems cannot function in absence of any of these components.

A microphone is the very basic component of PA systems. It is the device that captures the voice of a speaker and converts it into electronic signals. These signals are then processed by the rest of the PA system. It is must that the microphone must be of good quality because the quality of microphone is going to affect the signals that are sent to the PA systems.

There are different types of microphones but only a unidirectional microphone must be used with PA systems because they can only catch sound coming from a particular direction. This means that unwanted noise would not enter the system.

Then comes the mixer of PA systems. It is the task of mixer to take the input from microphone or a number of microphones and send it to the amplifier. The mixer also takes the output from amplifier and forwards the signals to multiple loudspeakers. While the mixer does not affect the audio quality by itself, if low quality connectors are used the sound quality may suffer a bit.

The third component of PA systems is the amplifier. As shown by its name, the job of amplifier is to boost the electronic signals so that they can easily travel to the loudspeakers through the complex web of wires. An amplifier is considered to be crucial for PA systems because they have immense effect on the sound quality and usage of low quality amplifiers can lead to severe distortion of sound.

The loudspeaker is the fourth component of PA systems. They are connected through the mixer and it is their task to convert the electronic signals into sound waves which people can understand. Most of the people tend to buy low quality speakers to cut costs. But if every other component is top quality and speakers are cheap, everything becomes a waste because the sound quality will be adversely affected.

As told earlier, PA systems are used to communicate messages to a large number of people at the same time. It is used in areas where a lot of people want to listen to one person like in speeches, music shows, or within buildings in order to inform everyone about something. PA systems are also used to to call a particular person when a number of people are present and it is difficult to locate the person concerned.

PA Systems