Surround Sound has its beginnings in the
movies. Surround Sound was an essential way of drawing audiences
into the world of cinema. In addition to the screen images, the
dialog, the feeling of 'being there" through sound effects, and
the music that embraces audiences have been combined to create a
thoroughly enjoyable cinematic experience.
Dolby Laboratories has contributed significantly to movie sound
development. Its first major development was Dolby Stereo,
followed in 1982 by Dolby Surround for the consumer market.
Improvements in this technology led to the development of Dolby SR
(Spectra Recording), which was introduced for consumers in the
form of Dolby Surround Pro Logic in 1987.
The primary difference between the consumer formats of Dolby
Surround and of Dolby Surround Pro Logic is that Dolby Surround
uses three channels (Left, Right and Surround), while Pro Logic
uses four channels (Left, Right, Surround and Centre). With the
addition of the Centre channel, the distribution of sound elements
becomes clearer In addition, by installing the adaptive matrix
circuit into the playback side, Pro Logic emphasises the sound
Dolby Pro logic is a totally analogue format, the advantages are a
Pro Logic amp can take the stereo sound from any stereo input and
decode the pro logic encoding in the stereo sound track. Pro Logic
has since been superseded by Dolby Digital, a superior sound
format that is mainly found on DVDs, fortunately nearly all Dolby
Digital amps are backward compatible with Pro Logic and therefore
your VCR and TVs sound output .