While the system itself might have more or fewer components based on the need of the event and the complexity of the system, they all work in generally the same way. They take in audio, whether it is music or simply someone speaking, and it then amplifies the signal so that everyone at the event will be able to hear it clearly. The complex systems can actually manipulate the audio in real time to get certain sounds and to ensure that it is as clear as possible. It all depends on the situation and event, as well as the venue.