There are a number of microphones and speakers in a PA system. All these devices work in tandem with each other because they are interconnected via a PA system mixer. The PA system mixer is a hub from where the audio signals are directed towards the proper direction.

PA system mixer is just like any other audio mixer. It has a number of channels to take audio from different sources as well as to distribute the audio signal to a number of target devices (speakers). Depending upon the type and make of the PA system mixer, it might be able to handle both analog and digital signals.

The input strip of the PA system mixer is the place which receives audio signal from microphones. It is equipped with XLR connector sockets where an XLR cable coming from microphone is plugged. Depending upon the number of connectors on the input strip the number of channels of a mixer is decided. The most common PA system mixers are the 8 channel mixers and 16 channel mixers. The other input sockets which are available on a mixer are RCA and quarter inch.

The second component of the PA system mixer is the EQ section. This is where the audio mixing takes place. All the signals from different channels converge here to form a single output audio signal. The signal coming out form the PA system mixer is sent to the amplifier where its strength is boosted manifold.

Once the amplifier has boosted the signal strength of the audio input given to it by the mixer, the signal is sent back to another mixer. Here the job of PA system mixer gets reversed. Instead of collecting multiple inputs into a single stream, the PA system mixer take the amplified audio signal from mixer and sends the stream out to various loud speakers so there is one input and many outputs as opposed to many input and one output in previous case.

You must be aware that while the mixer does not affect the sound quality per se, if any of the connector sockets, jacks and pins etc are made of low quality material, they would degrade the overall audio quality. High quality mixers come with specially coated connectors which provide the right balance between conductivity and resistance of electronic signals that are supposed to travel through these connectors.

The single most important consideration when you purchase a PA system mixer is the number of channels (connectors) that you want. The more there are channels in a PA system mixer, the more costly it will become. Remember that PA system mixer you want to purchase must have enough channels to accommodate the number of microphones as well as number of speakers in your PA system.