Sound amplification by stimulated emission of radiation phenomenon, known as the Larsen effect, is the result of a positive feedback. In general, every oscillator consists of three main parts. These are the power source or pump, the amplifier and the positive feedback leading to the output. The corresponding parts in a SASER device are the excitation or pumping mechanism, the active (amplifying) medium, and the feedback leading to acoustic radiation. Pumping can be performed, for instance, with an alternating electric field or with some mechanical vibrations of resonators. The active medium should be a material in which sound amplification can be induced. An example of a feedback
A/B Sound System eliminate the comb-filtering effect.” An A/B system is used in the Avon Theatre at the Stratford Festival in Canada. Stratford Festival sound designer William Fallon said, "I've found that it has also helped in creating separation and clarity in large production numbers, by being able to send half the cast down one path and the other half down another, either based on parts, blocking, leads vs ensemble, etc." A/B Sound System An A/B Sound System is a type of Sound reinforcement system or Public address system. Unlike a more typical sound reinforcement system, an A/B Sound System provides two electrically