Classe Audio SSP-800/CT-SSP owner manual Understanding Surround Sound

how many channels?

matrix or discrete?

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Understanding Surround Sound

Today’s sophisticated surround sound systems have spawned a bewildering array of technologies and acronyms. In this section, we’ll give you a basic understanding of what all that jargon means. As a result, you’ll be better equipped to take advantage of the best that home entertainment has to offer.

Today’s home entertainment systems reproduce soundtracks that include anything from one to eight separate channels of information. Examples include:

• Watching mono movies, such as Casablanca or The Wizard of Oz, having only a single channel of audio information in the soundtrack.

•Listening to a musical CD, which is typically stereo or 2-channel sound.

•Watching the original Star Wars in the original Dolby Surround Pro Logic format, which is four channels of information derived from two channels.

•Watching a recent movie or T.V. show in a 5.1-channel or

7.1-channel surround format, which identifies that the source material has either five or seven full-range signals for the front, surround, and rear speakers plus the .1 signal for the Low Frequency Effects (LFE), also referred to as the LFE channel, for the subwoofer.

Your SSP handles all of these tasks with ease, switching to an appropriate processing mode automatically upon sensing the nature of the incoming signal.

However, you may still have to select from the available choices. For example, disc-based media often contains multiple soundtracks with varying numbers of channels and even different languages. Because you may have to choose the one you want to hear using the menu of the media itself, you should know what jargon you’ll likely see.

When movie-makers first wanted to expand beyond simple stereo (left and right audio channels), they had a problem - the entire infrastructure on which they depended was stereo.

Dolby Laboratories solved that problem with a system called Dolby® Surround that embedded two extra channels of audio sound into the existing stereo pair so that specialized circuitry could retrieve the extra information with reasonable accuracy. This technique, whereby channels are mixed together with the intention of separating them later, is called matrix encoding and decoding.

The disadvantage, as you might expect, is that it is difficult to completely and perfectly separate two channels that have been mixed together.