Dolby Noise-reduction System - Dolby C

Dolby C

Dolby C was introduced in 1980. It provides about 15 dB noise reduction (A-weighted). It is constructed by combining the effect of two Dolby B systems together with an expansion to lower frequencies. The resulting recordings sound much worse when played back on equipment that does not have Dolby C noise reduction. Some of this harshness can be mitigated by using Dolby B on playback. It utilises anti-saturation and spectral skewing techniques. Dolby C first appeared on higher end cassette decks in the 1980s. The first commercially available tape deck with Dolby C was NAD 6150C, which came into the market in ca. 1981. It was also used on professional video equipment for the audio tracks of the Betacam and Umatic SP videocassette formats.