960L Owner’s Maunal Using The Reverb Program
The earliest efforts to improve sound reproduction
concentrated on broadening frequency response and
reducing distortion and noise. But even by the late
1930s, it was obvious that eliminating those barriers
to sonic realism weren’t enough. The spatial element
was missing.
The first attempt to restore this missing element was
stereophonic sound, introduced to the American public
via the Walt Disney film Fantasia, in 1941. Its three-
channel process could simulate surround directionality
by steering signals to speakers around the theater, but
was not true surround.Progress in stereo stalled during
World War II, but in the early ‘50s, stereo reappeared
with the advent of CinemaScope and similar
widescreen processes. Shortly thereafter, stereo
became available for home listening, first via tape, then
phonograph records, and finally, via FM radio.
Stereo added directionality and ambience. The
directionality was useful in movies and opera, but
otherwise of minimal concern to listeners. Room
ambience proved to be stereo’s real selling point for
music, helping create the illusion that the listener was in
a better acoustic venue than his living room. Some of
that illusion had been created in mono days by the
inclusion of reverb in the final mix, largely produced in
echo chambers (small, hard-surfaced rooms containing
speakers to reproduce the original sound and
microphones to pick up the added echoes). But in
mono, reverb levels had to be limited to avoid muddying
the sound. With stereo, the listener could more readily
pick out specifically positioned performers from the
general ambient background, enabling the amount of
reverb to be increased.
At the same time, music was being recorded more and
more with close-miked multi-track techniques that did
not capture the original ambience, and in studios where
there was little or no ambience to capture. This
accounts in large measure for the popularity of reverb
processors such as the Lexicon 480L.
Even with stereo, some spatial elements were missing.
In real life, we hear sounds and ambience from all
around us, not from just the front of the room. Adding
additional channels at the sides or rear of the room
seemed the answer, and surround sound made its
appearance in movies and in the home in the 1970s.In
films, where it served a dramatic purpose and where a
three-channel front speaker arrangement was
standardized, it succeeded.
For several reasons, surround sound flopped in the
home. There was a confusing array of recording
formats, each requiring slightly different playback gear.
The few quadraphonic recordings available were split
among these formats, reducing the choice still further
for listeners who were not equipped for every format.
Record producers could not decide whether to use the
extra channels to encircle the listener with performers
or to provide a front soundstage with surrounding
ambience. Most surround setups placed the extra
speakers in the rear corners of the room despite the
ear’s low sensitivity to lateral directional cues from
behind. And many consumers balked at the idea of
placing two more full-sized speakers in their rooms. A
major reason for the failure of home surround was the
recommended four channel format. Without a center
channel, Quad sound did not improve the listening area
over two channel stereo. To hear a recording one had
to be in the "sweet spot", a requirement that was greatly
reduced in cinema surround.
Surround’s salvation came from the movies and the
development of stereo VCRs. The widescreen films of
the 1950s carried multi-track sound on magnetic
stripes, but rear speakers mainly carried effects and
were often shut off between effects to reduce noise
from the narrow, hissy, mag stripes.With the advent of
70mm film, which had more room for soundtracks,
mixers began using offscreen channels to carry low-
level effects on a continuous basis, adding to the films’
sonic realism.
But most theaters were equipped only for standard
35mm films. In 1976 Dolby Labs introduced Dolby
Stereo, a matrix process that encoded surround sound
into two-channel optical soundtracks that were
compatible with standard cinema projectors. This
enabled a single release print to be used in theaters
with mono, stereo, or surround sound systems. When
these films were released on stereo videocassettes in
the early 1980s, the surround information encoded in
their two-channel soundtracks was carried over to the
home. With the addition of a low-cost matrix decoder
and additional amplifier and speaker channels, a
consumer could now have surround when watching
movies at home via tape and, eventually, via broadcast.
Even some made-for-TV programs incorporated
surround.
At least for home video, there was now a substantial
body of software with a common surround format.There
was also general agreement on where speakers should
be placed: three in front instead of two, and a pair of
surround speakers on the side walls. Home theater
began to take off, aided by the arrival of comparatively
Sound in Space: A Short History of Stereo and Surround5-5