What is a PA System?

PA Systems are used in many industries and what they consist of are various speakers which are placed in various places around a building or in one place depending on the purpose of it. It also has an amplifier and mixer which will increase sound levels depending on how loud they are needed to be and vary them. A microphone is also used to transmit messages that a user would speak through, it sends it to the speakers in the various locations so people can hear important messages. So simply it accepts sound from the source, amplifies it to a level you desire and distributes it to an audience. It can get sent to more than one place and has become an essential tool in most businesses. Some modern PA systems there are functionalities for the audience to speak back to the PA system so these messages are carried over to the original speaker of the message; it is kind of like sending back a reply to a message. There are 3 different components which are vital. These being:1)    The mixer – The mixer is the device which will set the tone of the original sound, it can change the level, pitch, tone and other acoustic settings, sometimes in concerts where people are singing loud an engineer will sit for sometimes the whole show and adjust the settings depending on where and when needed.2)    Amplifier – What an amplifier does is well, amplifies sounds and signals depending on what is desired. It will make the sound louder or quieter depending on what is needed. The amp however does not change the quality of the sound but will only make it louder and quieter.3)    Speakers – The speaker will distribute the sound, depending on where the PA system is used, and then the audience who are intended to receive messages from the PA will only be able to see the speakers. Unless it is at a show or concert or business seminar etc where you are focusing on the person on the stage. The speaker is one of the main features and many people believe the quality of the speaker will determine the quality of the system as a whole.Some schools use PA Systems, as well as hospitals, train stations, bus stations, airports, shopping centre's, supermarkets and many more. They use them to transmit important messages and announcements to everybody in the building as it may be too large to reach everybody without a PA system. They can also send messages out for members of staff to report to a certain area of the building without the hassle of finding them and telling them.There are also large scale PA systems which are used to amplify sounds for Theatre productions or concerts and gigs. They are a lot more complex than the average PA system and generally will need a few technicians to operate them correctly. What these systems do is transmit any on stage noise into the audience and inform any people back stage of what is going on on-stage. They are extremely complex and they take the name SR systems. They have a lot of microphones as more than one person may need to speak or sing at the same time.