AC-1, AC-2, and AC-3

Dolby AC-1 was the first digital coding technology introduced in 1987, A development that would later become HDTV (High-Definition TeleVision). Later in 1989, Dolby introduced AC-2, which had a better audio quality and a reduced bitrate. Finally, in 1991, Dolby introduced AC-3, which includes 5.1 channels and operates at 320 kbps.

Sound terms