#4 What is the difference between Pulse-Code Modulation (PCM) and
Dolby Digital® technology?
Pulse-Code Modulation (PCM) and the Dolby Digital® technology
refer to different types of digital audio recordings. PCM is the
conventional method for converting analog audio into digital audio.
The PCM audio recorded on DVD is a two-channel digital, stereo
audio track.
The Dolby Digital® technology, which was originally called AC3,
was developed specifically for multi-channel applications, including
film sound and digital surround sound in the home. Dolby Digital®
technology uses a 5.1 or six channel format. The 5 channels
include the Stereo left and right front channels, Stereo left and right
surround channels, and the center channel. There is also, a Low
Frequency Effects (LFE) channel for the subwoofer, which is
counted as the 0.1 channel since it functions only when a deep
base effect is needed.