The Dolby Digital format uses six independent audio channels: For professionals, instead of an AC3 decoder, Dolby Digital uses a system called SR-D. For this reason, the Dolby Digital format is sometimes called Dolby AC3. This algorithm can compress audio streams by a factor of 10 to 12 with a 16-bit sampling rate of 48 kHz, for an overall bitrate of 384 kbps. It should be noted that Dolby Digital is often incorrectly confused with the generic term 5.1.įor consumer electronics, the Dolby Digital format relies on a compression algorithm called Audio Coding 3 (AC3). The Dolby Digital format's bandwidth falls between 20 Hz and 20 kHz, which is also the human hearing range (note that it varies between individuals).ĭolby Digital audio tape can be encoded in either of the following formats: