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There are many multi-channel formats available. Table1, below, identifies
the most common multi-channel formats to help you sort out some of the
possibilities.
Table 1: Common multichannel modes
Name
# Chs
Matrix/Discrete
Comments
analog stereo
2
Discrete
Found on almost all sources, including
tape decks, tuners, and CD players.
analog multi-
channel input
6-8
Discrete
A multi-channel analog input used
mostly for SACD & DVD-Audio.
Dolby Surround
Pro Logic
4
Matrix
The original matrix decoding system
designed to squeeze four channels into
two and then retrieve them.
Dolby Pro
Logic II
Up to 5.1
Matrix
An improvement of Dolby’s original
Pro Logic matrix decoder, Dolby PLII
is designed for 5.1 surround systems.
Dolby Pro
Logic IIx
Up to 7.1
Matrix
An improvement of Dolby PLII, this
version uses the 2ch or 5.1channel
source audio to create as many as 7.1
channels (depending on speaker setup)
of surround sound.
Dolby Digital
(formerly AC-3)
1.0-5.1
Discrete
The most common modern digital
source, used in HDTV, DVD, etc.
Dolby
Digital EX
6.1
Discrete
A 7th channel of discrete information
was recorded during filming and
is encoded into the media. This
information is used to create a single
rear center, or two mono rear centers
depending on the speaker setup (6.1
or 7.1).
DTS
1.0-5.1
Discrete
Similar to Dolby Digital in practice,
though it uses a different technology.
DTS-ES Matrix
6.1
Mostly Discrete The center rear channel is a matrix
channel encoded into the left and
right surround channels. The
processor reads flags and “unfolds”
the center rear channel information;
all other channels are discrete.
DTS-ES Discrete
6.1
Discrete
All 6.1 channels are discrete
DTS Neo:6
5-6
Matrix
Designed for the playback of film or
music sources and can derive 5 or 6
channels with surround and/or rear
speakers
