Microphone helps in magnifying the volume of the sound originating from audio devices. Microphones of condenser variety can defy the elements and create high-quality audio signals. Mixer permits the sound originating from various channels to broadcast at, unlike levels. CD tracks can be plugged into the Public Address system. Amplifier might be used in parallel or in combination with the mixer. It manipulates the frequency variants. The decibel quality of the sound emitting from the speakers is termed as Amplifier gain.