Audio System Restaurant audio systems contain a variety of components including amplifiers, pre-amplifiers, mixers, source components and multiple speakers. Commercial sound systems contain sensitive circuitry and electronics prone to damage from power surges and other electrical disturbances. Not to be confused with inexpensive stereo systems, commercial grade audio systems may have significant value; large sophisticated systems may cost many thousands of dollars. © 2007 The Boiler Inspection & Insurance Company of Canada.     All rights reserved.