12 Public address
It would be as well to start with a clarification of the term ‘public address’, or ‘PA’ for short. It obviously means having a system of loudspeakers placed so that the output of microphones or other sources can be fed to a relatively large number of people. It is, though, convenient to realize that there are three quite different applications:
1. The audience is remote from the microphones. A typical example is that of a sporting event where the commentator is usually in a small room some distance from the loudspeakers. Another good example is on railway stations where the aim is to inform people of train arrivals, delays and so on. In both cases intelligibility is (or should be!) the most important factor. Sound quality ...