Compression isn't the only automatic gain-changing effect that has applications at mixdown—it's one of a whole family called “dynamics processes,” or simply “dynamics.” Other members of this family seem frequently to be ignored in the small studio, but they can also have their uses. This chapter explains some of these potential applications.
Whereas compression reduces dynamic range by turning down loud sounds, expansion does the opposite—it increases the dynamic range by turning down quiet sounds. There are a number of common applications for expanders when balancing a mix, including the following:
Reducing low-level background noise between vocal or instrument phrases
Reducing hi-hat ...