Lexicon CP-1 Theory Of Operation page 20

Multi-Channel Music & Cinema Systems
Theory and Design
The requirements for processing sound for film viewing are quite different Surround
than those for music listening. Music demands recreation of the original
performance venue, or the evocation of an appropriate setting, as well as the
creation of a believable soundstage. When visual images are introduced, not
only is strong audio imaging necessary to reinforce the illusion that dialog
originates at the screen image, but a diffuse soundfield must be created
which envelops the viewer without distracting attention from the screen.
In addition, films are designed to provide an enveloping experience in
large, reverberant auditoriums where background noise is a significant
consideration, where the screen dominates the field of vision, and where the
sound must be as uniform as possible over a large seating area — in short,
quite a different environment from your living room.
When all of these factors are taken into consideration, it becomes obvious
that no single speaker system or single method of processing is optimal, or
even adequate, for all types of music as well as for audio/video material.
Lexicon processors are able to optimize the listening experience of any
material precisely because they provide such a wide range of processing
options. This flexibility is readily apparent in the variety of Surround effects
available to the user, each optimized for maximizing listener involvement
in different types of material played on a system whose speakers are laid out
primarily for films.
TV MATRIX provides surround effects to enhance television viewing of
monaural, stereo and stereo-synthesized programs. This program has the
most flexibility in adjustment of any of the Surround effects.
MUSIC LOGIC and MUSIC SURROUND use a unique ambience extraction
method which can provide spectacular results with music, as well as
providing seven channels.
PARTY (Full Range) allows unprocessed music to be played over all the
speakers for background music, or for maximum acoustical output of the
system.
MONO LOGIC expands the music and effects on monaural films into the
surround channels while leaving dialog in the front center.
PRO LOGIC provides the same decoding used in Dolby Stereo theater
systems, using as many as eight speakers for front, center, side, rear and
subwoofer channels. All side and rear channels are driven in parallel, or
monaural.
THX Effects combine Dolby Pro Logic decoding and the spectral enhance-
ments of the LucasArts Home THX Cinema system. Home THX Cinema
enhancements are provided for film soundtracks recorded in the Dolby
Digital and DTS formats.
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