Classe Audio SSP-300 - Manual (Page 35)

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The disadvantage of matrix decoding is what you might expect – it is tough to
completely and perfectly separate two things that have been mixed together.
Once you have baked a cake, it is difficult to get back to the eggs and flour.
By contrast, modern soundtracks use discrete channels of information. That is,
each speaker has a distinct signal that is completely independent of every other
channel. This approach is clearly more desirable, since it gives the movie makers
more creative control over the quality of your experience. Musicians also prefer
discrete formats, since it allows them to place their instruments and voices with
greater precision, to create the musical effects they desire.
There is a host of various multichannel formats available. Here is a summary
grid to help you sort out the possibilities.
multichannel formats Name # Chs Discrete? Notes
analog stereo 2 yes as found on almost all sources,
including tape decks & CD players
multichannel in 6-8 yes a multichannel analog input used
mostly for SACD & DVD-Audio
Dolby Surround 4 matrix the original matrix decoding system
Pro Logic designed to squeeze four channels
into two and then retrieve them
Dolby Digital 1.0-5.1 yes the most common modern digital
(AC-3) source, used in HDTV, DVD, etc.
Dolby Digital EX 6.1 mostly yes the center rear channel is a matrixed
channel hidden in the left and right
surround channels; all others are
discrete
DTS 1.0–5.1 yes similar to Dolby Digital in practice,
though it uses a different technology
DTS-ES Matrix 6.1 mostly yes the center rear channel is a matrixed
channel hidden in the left and right
surround channels; all others are
discrete
DTS-ES Discrete 6.1 yes all 6.1 channels are discrete
post-processing possibilities Once the SSP-300 has decoded the signal it is provided in the appropriate
manner, you still have some options as to whether you would like additional
processing of the signal.
This point is sometimes confusing. The first thing any surround processor must
do is to recover the various channels that were intended to be delivered into
your home. This might be a single mono signal, or a Dolby Digital Surround
EX soundtrack with 6.1 channels, or anything in between; it may have been
delivered to your home via a satellite receiver, a cable set top box, or a simple
DVD disc. Regardless, the first task is to recover as many channels as are being
delivered, with great accuracy and fidelity.