A system that amplifies or enhances the sound of a speaking person, singer, or musical instrument. Sound-reinforcement systems are used to increase the clarity of the original sound as well as to add loudness and reverberation. Those that improve loudness and clarity are often called public address systems, and those that improve reverberation characteristics are called reverberation enhancement systems. Systems for increased loudness are used when listeners are located far from the sound source, as in a large audiorium or outdoors. Systems for increased clarity are used to overcome the effects of unwanted noise or excessive reverberation in a room (such as concert halls and churches with reverberation characteristics designed for music). Reverberation enhancement systems are used to add sound field components, such as reverberation to rooms having unsuitable levels of direct, early reflected sound and reverberant sound or having short reverberation times.