The sound system term refers to public sound systems used to address as many customers as possible. Sound systems usually have a distribution system (the whole route is generally powered by one amplifier with an output transformer connected to a great number of speakers with a conversion transformer).
Essential sound system features include broadcast clarity, sufficient volume, possibility of connection and collaboration with electronic security and fire alarm systems, high reliability in long-term operation, independence of grid outage, background music, and speaker division to groups (zones) and so-called forced listening.
