Technical Description - Marantz SR7500/A1B Service Manual

2. TECHNICAL DESCRIPTION

®
THX is an exclusive set of standards and
technologies established by the world-renowned
film production company, Lucasfilm Ltd. THX
resulted from George Lucas' desire to reproduce
the movie soundtrack as faithfully as possible both
in the movie theater and in the home theater.
THX engineers developed patented technologies
to accurately translate the sound from a movie
theater environment into the home, correcting the
tonal and spatial errors that occur.
When the THX mode of the SR7500 is on, three
distinct THX technologies are automatically
added:
Re-Equalization-restores the correct tonal balance
for watching a movie in a home environment.
These sounds are otherwise mixed to be brighter
for a large movie theater. Re-EQ compensates for
this and prevents the soundtracks from being
overly bright and harsh when played in a home
theater.
Timbre Matching-filters the information going to
the surround speakers so they more closely match
the tonal characteristics of the sound coming from
the front speakers.
This ensures seamless panning between the front
and surround speakers.
Adaptive Decorrelation-slightly changes one
surround channel's time and phase relationship
with respect to the other surround channel.
This expands the listening position and creates
with only two surround speakers the same
spacious surround experience as in a movie
theater with multiple surround speakers.
The Marantz SR7500 was required to pass a
rigorous series of quality and performance tests, in
addition to incorporating the technologies
explained above, in order to be THX certified by
Lucasfilm Ltd.
T H X r e q u i r e m e n t s c o v e r e v e r y a s p e c t o f
performance including pre-amplifier and power
amplifier performance and operation, and
hundreds of other parameters in both the digital
and analog domain.
Movies which have been encoded in Dolby Digital,
DTS, Dolby Pro Logic, stereo and Mono will all
benefit from the THX mode when being viewed.
The THX mode should only be activated when
watching movies which were originally produced
for a movie theater environment.
This is because they were originally mixed for a
small room environment.
THX is a trademark or registered trademark of THX
Ltd. Surround EX is a jointly developed technology
of THX and Dolby Laboratories, Inc. and is a
trademark of Dolby Laboratories, Inc. Used under
authorization. All rights reserved.
THX Surround EX—Dolby DIgital Surround EX is a
joint development of Dolby Laboratories and THX
Ltd.
In a movie theater, film soundtracks that have been
e n c o d e d w i t h D o l b y D i g i t a l S u r r o u n d E X
technology are able to reproduce an extra channel
which has been added during the mixing of the
program. This channel, called Surround Back,
places sounds behind the listener in addition to the
currently available front left, front center, front
right, surround right, surround left and subwoofer
channels. This additional channel provides the
opportunity for more detailed imaging behind the
listener and brings more depth, spacious
ambience and sound localization than ever before.
Movies that were created using the Dolby Digital
Surround EX technology, when released into the
home consumer market may exhibit wording to that
effect on the packaging. A list of movies created
using this technology can be found on the Dolby
web site at www.dolby.com. A list of available
DVD software titles encoded with this technology
an be found at www.thx.com.
Only receiver and controller products bearing the
THX Surround EX logo, when in the THX Surround
EX mode, faithfully reproduce this new technology
in the home. This product may also engage the
THX Surround EX mode during the playback of 5.1
channel material that is not Dolby Digital Surround
EX eocnded. In such case, the information
delivered to the Surround Back channel will be
program dependent and may or may not be very
pleasing depending on the particular soundtrack
and the tastes of the individual listener.
"SURROUND EX™" is a trademark of Dolby
Laboratories. Used under authorization.
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