The designated digital audio format for DVD, HDTV, and select laserdiscs and satellite TV broadcasts, Dolby Digital can include from one to six channels of sound. "5.1-channel" Dolby Digital has 6 discrete digital audio channels: 5 full-bandwidth channels (for front left/right, center, and surround left/right) and 1 "low frequency effects" subwoofer channel.

Some receivers have Dolby Digital decoding built-in; others, known as "5.1-ready," have a 6-jack input for hooking up an external Dolby Digital decoder (or a DVD player with built-in decoding).