You might think that surround sound is a relatively new development. But the concept of having a soundtrack surrounding the listener starts well before today's home theater erain fact, it dates all the way back to the 1940s!
Surround Sound in the Movies
Surround sound started as a way to immerse movie-going audiences in the film they were watching. From the very beginning, the movies have driven the development of surround sound technology.
The 1940s: Fantasia
In many ways, Walt Disney can be considered the inventor of surround sound. When the groundbreaking movie Fantasia was still in development, Disney met with conductor Leopold Stokowski to discuss the film's classical music score. Stokowski suggested that Disney contact the engineers at Bell Labs, who were working on a nascent multiple-microphone stereo recording technology. Intrigued by the technology, Disney thought it would be wonderful if, during the movie's "Flight of the Bumblebee" segment, the musical sound of the bumblebee could be heard flying all around the audience, not just in front of them.
Disney put his engineers to work on the challenge, with the result that Fantasia, released in 1941, became the very first film to incorporate surround sound. Disney employed the proprietary Fantasound technology to create a surround sound field with left front, center front, right front, left rear, and right rear channels. The main soundtrack incorporated only the front three channels; the two rear channels were recorded on a separate reel of film, and "steered in" separately when needed.
Unfortunately, the additional equipment necessary to reproduce Fantasound was too costly to roll out on a widespread basis. Only two Fantasound systems were sold to theaters: New York's Broadway Theater and the Carthay Circle Theater in Los Angeles. These installations cost $85,000 apiece and included 54 speakers placed throughout the auditorium. Disney also produced two scaled-back road show versions of the Fantasound system, at $45,000 each, although these traveling versions didn't include the surround speakers.
The 1950s: Multiple-Channel Stereo
The Fantasound system proved too complex and too costly for other studios to adopt. It took another decade for Hollywood to embrace a more affordable multiple-channel sound technologywhich it did in conjunction with the birth of the new widescreen film formats, in particular Cinerama and CinemaScope.
The new wider-screen formats needed multiple channels to fill the entire front field of the movie screen. The solution was a wall of sound, employing four to six audio channels for a widescreen stereo effect. Among the earliest multiple-channel movies were 1952's This is Cinerama (with seven-channel surround sound) and 1953's The Robe (in Cinemascope, with four-channel sound).
Prior to this point, one sound channel was optically encoded onto a strip of film, the same way the picture itself was recorded. To fit more sound tracks onto a strip of film, multiple tracks were encoded magnetically. A film frame has room for up to six of these magnetic audio tracks. Several of the early widescreen formats added a surround sound channel to this standard stereo setup. In a standard four-channel setup, the tracks are assigned to left, center, right, and surround. The mono surround channel was fed to multiple speakers along the sides and rear of the theater. The surround channel was typically used for ambient background noise or other sound effects, thus inspiring the name "effects channel."
Unfortunately, the cost of these technologies proved prohibitive, and theatrical surround sound died out by the end of the 1950s.
The 1970s: Dolby Stereo
True surround sound made a comeback in the 1970s with the introduction of Dolby Stereo. In spite of its name, this was an optical four-channel technology, introduced in 1976 by Dolby Laboratories.
Instead of using magnetic audio tracks, which tended to be of lower fidelity, Dolby reverted back to the earlierand superioroptical recording technology. It also added noise-reduction technology for clearer playback.
The big boost for surround sound was the release of a single movie1977's Star Wars, with its swooping rear-channel effects. The success of Star Wars inspired theater owners to upgrade their sound equipment to the Dolby Stereo standard, and led to other producers and studios embracing the surround sound format.
The 1980s: Dolby SR and THX
Throughout the 1980s, more and more movies employed the Dolby Stereo surround sound system. In 1983, Lucasfilm introduced THX certification (named after George Lucas' first film, THX 1138), a set of technical standards designed to ensure a high-quality playback of film soundtracks in specially equipped movie theaters. In 1987, Dolby introduced Dolby SR, an optical four-channel system that offered wider dynamic range and a broader frequency response than the previous Dolby Stereo system.
The 1990s: Dolby Digital Surround, DTS, SDDS, and EX
Cinema surround sound became digital in 1992 with the introduction of Dolby Digital Surround (originally known as Dolby AC-3, short for audio coding 3). This system still encodes the audio information on a film's optical tracks, but in digital format instead of in analog fashion. Dolby Digital also introduced more channelsa 5.1 configuration with left front, center front, right front, left surround, right surround, and a separate low frequency effects (LFE) channel for deep bass.
In 1993, the Digital Theater Systems company introduced the competing DTS surround sound technology. Like Dolby Digital, DTS is a digital 5.1-channel system. Unlike Dolby Digital, however, DTS records the audio channels on CD, which on playback is synchronized to the film's time code. The first DTS movie was 1993's Jurassic Park.
A third company entered the surround-sound fray in 1993. Developed by Sony, the Sony Dynamic Digital Sound (SDDS) technology is an optical system like Dolby Digital, but with 7.1 channels arranged in a unique patternfive front channels (left, left center, center, right center, right), left and right surrounds, and the low frequency effects (subwoofer) channel. This multiple-front speaker system purportedly produces better dialogue imaging; the first SDDS film was 1993's The Last Action Hero.
In 1999, Dolby introduced yet another new surround sound technology, Dolby Digital Surround EX. This 6.1-channel optical system adds a rear surround channel to the previous left and right surrounds. The first EX movie was Star Wars: Episode OneThe Phantom Menace.