Dynamic range is the ratio between the largest and smallest possible values of a changeable quantity. In audio engineering, dynamic range generally refers to the distance between the loudest possible sound and the quietest possible sound in an audio recording. In a multi-track recording, each constituent track has a unique dynamic range; there is also a “master” or overall dynamic range, which is the total dynamic range of the tracks mixed together into the master bus. Consequently, dynamic range processing is often applied to tracks at an individual basis as well as on the master channel (the over-all mix). Fundamentally, dynamic range can either be increased or decreased, but there a several types of dynamic processors that act on the signal in different ways, producing different effects that utilize the inherent dynamic range of acoustically generated sounds.