User's Manual

H3-D Surround Sound Microphone User Guide
Rising Sun Productions Ltd. page 5
A Brief Overview of Surround Sound
In the beginning there was mono. No matter how many speakers
there were, the sound coming from each speaker was the same. In
monaural recording, the effect was as if all the sound was recorded
from the same single location, and for the most part this was how it
was recorded.
In 1940, Disney introduced surround sound to cinemas with the
movie Fantasia, using three channels behind the movie screen,
with additional speakers on either side and at the rear.
Implementation was expensive, and the results were demonstrated
in only two theaters — one in New York and one in Los Angeles.
In the 1950s, stereo recording was introduced to the mass
consumer market. Stereo is based on the premise that we have two
ears. If the sound is recorded from two sources, we get a better
image of where the sound is coming from. Through the 1960s,
stereo sound swept monaural out of the marketplace.
Throughout the seventies there were a number of experiments with
quadraphonic sound for the home market. Quad sound failed to
catch on for a variety of reasons — lack of material, high cost of
systems and lack of consumer demand.
In 1970, George Lucas’s Star Wars introduced Dolby Stereo to
movie theaters, and within a few years it became the most common
audio format. Contrary to its name, Dolby Stereo can actually
deliver four sound sources, thanks to an ingenious principle called
matrixing: left, right, center and rear. If the theater is not set up for
four channels, the sound is delivered effectively as conventional
stereo. Dolby Surround and Dolby ProLogic are home cinema
versions of Dolby Stereo. For television home video, the four
signals are compressed into two conventional stereo tracks, and
then decompressed into four if the home equipment supports
surround sound. This compression is referred to as 4-2-4.
Today, surround sound in theaters is delivered most commonly by
Dolby Digital systems, including Dolby Digital 5.1, Dolby AC-3
and Dolby SR-D (Spectral Recording Digital). Dolby Digital
employs six sound sources, as follows:
• Center
• Left
• Right
• Left surround
• Right surround
• LFE (or Low Frequency Effects)