ABSTRACT
Performance audio systems traditionally break down into two basic types: reinforcement and playback. Reinforcement systems use microphones, mixers, amplifiers, and speakers to bring live music, singing, speech, or other sounds to a larger audience than otherwise would be possible acoustically. These systems are used in musical or other live productions-everything from rock and roll to Broadway theatre. Playback systems present prerecorded music, dialogue, or effects to an audience, such as those found in legitimate and corporate productions, special events, theme parks, product launches, and even rock-and-roll concerts (although the audience may not know it). With the explosion of digital sound technology, more and more productions are using hybrid reinforcement/playback systems-the (human) reinforcement mixer for a Broadway show is able to press a single button and initiate complete sound-effects sequences. Conversely, a playback operator for a corporate presentation could also control a few channels of microphones. However, because sound and audio is so complex and is significantly affected by environmental conditions, performer variability, and other factors, many audio systems, while digital, are entirely manually operated-although the (human) mixers may use considerable computer horsepower to make their mixing jobs easier.
