[audio] CX is a noise reduction system for recorded analog audio. It was developed by CBS Laboratories (a division of CBS) in the late 1970s as a competitor to other noise reduction (NR) systems such as Dolby and dbx, and was officially introduced in 1981. The name CX was derived from `Compatible eXpansion,` a feature of the technique. The ... Found on http://en.wikipedia.org/wiki/CX_(audio)