DPL or Dolby Pro Logic sound begins with 4 channels and is mixed down and encoded as 2 channels for transfer. This encoded signal is easily carried via videotape, satellite, laserdisc, DVD or TV broadcast: or any stereo source. During playback, your DPL receiver processes the compatible signal back to 4 channels from 2.
Types of Channels:
2 discrete, full-bandwidth channels (front left and right); 1 matrixed, full-bandwidth channel (center); 1 matrixed, limited-bandwidth channel (surround left and right)
Dolby Pro Logic is a matrixed multichannel system, which means that some channels are actually derived from other channels. In this case, center channel sounds are created from parts of the front right and left channels. The single matrixed surround channel is split and sent to the surround speakers, so both surround speakers play the same sounds.
The Entrance of Dolby Pro Logic II
Dolby Pro Logic II, on the other hand, improves on
original Dolby Pro Logic with special circuitry that creates a convincing
5.1-channel experience with stereo, full-bandwidth surround channels! And yet
Dolby Pro Logic II is using the same Dolby Surround-encoded and stereo sources
that Dolby Pro Logic uses. Receivers with Dolby Pro Logic II will give extra
intensity to the 12,000 VHS movies with Dolby Surround and the limitless TV
broadcasts and music available as stereo sound. Yet even this format is only a
supplement to the impressive 5.1-, 6.1- and 7.1-channel surround sound
available from digital sources.
Types of Channels:
2 discrete, full-bandwidth channels (front left and right); 3 matrixed,
full-bandwidth channels (center, surround left and right); 1 subwoofer
channel via Pro Logic II's bass management
Works sited - Crutchfield
Copyright 2002. All rights reserved. Reprinted by permission.
