McIntosh MX130

HOME THEATER
AUDIO
CHANNEL
CONFIGURATION
WITH DOLBY
PRO LOGIC™
AND HOME
THX
®
AUDIO
Ail movies produced by major film companies have soundtracks that are encoded with
Dolby Surround Sound. The decoding process is called Dolby Pro Logic and results in four
separate soundtracks which are Left Front, Center, Right Front, and Surround sound. The Dolby
Pro Logic decoded surround signals are monaural, but are reproduced by a non directional
loudspeaker on each side of the listening area. The Dolby Surround concept is the heart of
the Home Theater audio and video experience.
Dolby Surround encoding is also used for MTS and satellite broadcasts as well as other
audio-only program sources such as compact discs. Use the MX130 CINEMA 1 mode with
its Dolby Pro Logic processing to enjoy listening to these other program sources.
Home THX Audio circuits further process all the Dolby Pro Logic decoded signals including
the generation of separate spatially expanded left and right surround signals. Home THX Audio
also specifies that a subwoofer should be used. A Home THX Audio system therefore requires
six discrete audio channels and six corresponding loudspeakers.
The MX130 provides six audio channels to take full advantage of the exciting sound
reproduction capabilities of a Dolby Surround encoded movie soundtrack. When the Mclntosh
THX-M module is installed in the MX130, the audio enhancements possible by Home THX
Audio signal processing also will be available.
Descriptions of the functions of each channel of a Dolby Surround soundtrack as decoded
by Dolby Pro Logic and the addition of Home THX Audio processing, will help you in better under-
standing the use of the various controls, switches and operating procedures of your MX130.
DOLBY SURROUND, LEFT FRONT and RIGHT FRONT
These two channels are stereo channels in the traditional sense. The left and right signals
provide ambience, depth and spaciousness for reproduction of music and sound from a Dolby
Pro Logic decoded movie soundtrack. The front channels also reproduce similar information
from a two channel stereo source such as a compact disc or audio tape.
DOLBY SURROUND, CENTER FRONT
Dolby Surround movie soundtracks are encoded with a Center channel, which also includes
dialog information, to increase the realism of the home theater experience. The Dolby Pro
Logic decoded Center channel is reproduced through a loudspeaker placed in the front center
location, either above or below the viewing screen. A Center loudspeaker provides greater
intelligibility of a movie dialog and also contributes to the overall sound realism.
DOLBY SURROUND, LEFT and RIGHT
Dolby Surround movie soundtracks are encoded with a specially processed surround sound
signal. When decoded by Dolby Pro Logic processing circuits, the surround sounds can in-
clude all types of acoustical information and sound effects that enhance the listening enjoy-
ment of a movie. The Dolby Pro Logic decoded surround sound channel is monaural, however,
it is reproduced through two separate loudspeakers placed on the left and right walls of the
listening area. The surround loudspeakers should radiate sound in a non directional manner,
allowing the listeners to hear only the sound that is reflected off the wall surfaces and not
directly from the loudspeakers. Properly installed surround loudspeakers will provide ambience,
and should not distract from the direct sound reproduced by the front loudspeakers.
HOME THX AUDIO SURROUND CHANNELS
Home THX Audio circuits add additional processing to all the original Dolby Pro Logic
decoded signals. The monaural surround signal is further processed into two separate spatially
expanded left and right surround signals.
There are specific Home THX Audio requirements for surround sound level calibration. This
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