servo-loop mechanism


(n.) A self-regulating feedback system. It consists of a sensing element, an amplifier, and a servomotor to automatically control a mechanical device. In audio, this usually refers to a class of electronic control circuits comprised of an amplifier and a feedback path from the output signal that is compared with a reference signal. This topology creates an error signal that is the difference between the reference and the output signal. The error signal causes the output to do whatever is necessary to reduce the error to zero. One example is a loudspeaker system with motional feedback. A sensor is attached to the speaker cone and provides a feedback signal that is compared against the driving signal to create more accurate control of the loudspeaker.