your system!
MOTION PICTURE SOUND:
A BRIEF HISTORY
In the early 40’s, the large movie studios owned their own theatres and could enforce
quality standards. In those days motion picture theaters provided higher quality sound
reproduction than home radios or phonographs.
An anti-trust action forced the studios to sell their theatre holdings in the 50’s. When the
theatres became independently owned, each theatre could choose which films it wanted
to show. In turn, the studios eliminated their technical staffs which had been responsible
for maintaining sound quality standards. As a result, the quality of sound in the theatres
failed to keep pace through the 50’s and 60’s.
The turning point came in the 70’s with the introduction of the Dolby Stereo
®
recording
process by Dolby Laboratories. The consumer electronics market tends to think of Dolby
exclusively as a noise reduction system used in cassette decks, but a significant portion
of Dolby’s business is in the professional audio industry. Dolby Stereo allows four channels
of sound to be recorded on the two available optical soundtracks of a 35mm movie print,
with excellent results. One of the first commercial successes of this new technology was
STAR WARS in 1977.
The impact of STAR WARS on the movie-watching public is hard to overestimate. The
quality of the sound track caught everyone’s attention and changed what people expect-
ed from film sound. Suddenly, people rushed to see new releases in better-sounding the-
atres, and the ones which upgraded their sound systems were rewarded with increased
revenues.
Unfortunately, there was no standard of performance for the sound systems in theatres.
Even the best auditoriums sounded different from each other and from the sound the
director heard in the film studio because of variations in room acoustics and sound sys-
tems. In 1982, George Lucas gave his full support to create a new movie theatre sound
system standard: the THX Sound System.
The THX Sound System was designed to complement and enhance the playback of
Dolby Stereo, which was the established standard for film sound recording. THX picked
up where Dolby Stereo left off, encompassing standards and technologies for power
amplifiers, speakers, patented Lucasfilm technology and the acoustics of the theatres
themselves to ensure the best possible reproduction of movie soundtracks.
By 1991, THX systems had been installed in nearly 500 movie theatres and studios world-
wide, with many more in various stages of construction. THX has become the industry
standard for post-production mixing facilities as well as for theatres and/or studios.
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