It it were not for Dolby Stereo, the 70mm format would probably have been completely extinct in the early 70s. Dolby´s noise reduction system, known as Type A, was applied to studio recordings of film sound in the early 70s, and subsequently also applied for stereo presentation in cinemas a few years later. That idea was an unprecedented, giant step into better everyday sound presentation in cinema. 

Dolby Stereo´s breakthrough came with the release of "Star Wars" in 1977. Everyone sat up and took notice.

Even though the 35mm optical sound quality was improved, the absolute creme-de-la-creme of movie sound was only obtainable from magnetic sound available only from 70mm prints. Therefore, the 70mm format was reintroduced to cinemagoers, still with 6-track stereo, but now Dolby encoded. The original 6 discrete uncompressed channels were reconfigured into a left, center and right screen channel plus a surround channel (renamed from effects channel). Except for a few rare 70mm show-prints (that used the original 5 discrete channels behind the screen with directional dialogue) used in major first run cinemas in Los Angeles, New York and London, the sound was now "folded in" in such a way that most dialogue came from the center channel. The tag line "In 70mm and 6-Track Dolby Stereo" was a clever marketing gimmick that for 20 years and nearly 250 films secured the best possible sound reproduction in the cinema.

A Brief History of Dolby Laboratories
Edited from www.dolby.com

In 1965, American engineer and physicist Ray Dolby established Dolby Laboratories in London. His aim was to develop practical noise reduction systems for improving sound quality in a variety of professional and consumer environments. The resulting innovations have made Dolby a watchword for quality audio throughout the world.

Today, Dolby Laboratories continues to pursue genuine, long-term improvements in sound quality. The company's research in analogue and digital audio is applied both to the professional products which Dolby manufactures and sells, as well as technology which is licensed to other manufacturers for their own professional and consumer products. Innovations from Dolby Laboratories are used in every country where sound recordings are made, and can be heard in everything from portable cassette players to high-end home theatre systems, radio stations to satellite music systems, quality movie theatres to professional recording studios.

Most recently, the company's latest digital audio technology -- referred to as Dolby Digital (using AC-3) -- has brought new excitement to the soundtracks of a thousand plus films, and to home listeners on current generation laser discs. Dolby Digital also is bringing excitement to home listeners via the audio tracks on DVD, and would be the standard audio on the new high definition television (HDTV) system proposed for implementation in the United States if it ever catches on with the public.

Dolby's Business Philosophy

Design Excellence, Responsive Service, Long-Term Results.

Worldwide Facilities
Dolby Presentation Cinema in San Francisco

Dolby Laboratories' corporate headquarters, housing research and development, marketing, licensing and administrative staff, is located in San Francisco's historic Potrero Hill district, in a renovated brick warehouse dating from the early 1900s. 

The facility includes a state-of-the-art film screening room and listening and testing facilities for the wide range of consumer products incorporating Dolby technology. North American manufacturing operations, using the latest in surface mount and other current manufacturing processes, are housed a short distance away in Brisbane, California. This site serves customers throughout the Americas, Japan and Korea.

Dolby Laboratories' European base, in the Wiltshire, England countryside, is home to marketing, licensing, administrative and manufacturing staff serving customers in Europe and Asia. This facility, constructed to Dolby's specifications, includes a screening room and full-scale manufacturing operations which also use the latest in surface mount and other current manufacturing processes.

Additionally, Dolby Laboratories maintains two film division offices, located in New York and Los Angeles, to provide on-site, responsive service to filmmakers and recording professionals working on Dolby sound mixes. Both offices host frequent technical seminars and other events of interest to the behind-the-scenes film and audio community.

For professional products, Dolby Laboratories' worldwide network of dealers and distributors is available to assist customers with their product needs for studio, broadcast, and cinema sound equipment. For consumer products, retailers throughout the world are familiar with Dolby technologies for cassette noise reduction and home theatre sound.

Dolby Laboratories employs approximately 500 people worldwide.

Dolby Investigates Film Sound

In the late 1960s, even as home stereo B-type noise reduction was coming to market, Dolby began to look further a field for applications of its noise reduction technology. One area that looked promising was film sound, in particular, the photographic or "optical" soundtrack, introduced in the late 1920s. Thanks in great part to Dolby's efforts, that analog optical track is still by far and away the most popular way of providing sound with film.

The optical soundtrack has many advantages, including economy, reliability, and relatively long print life. Equally as important, 35 mm film with optical sound is a truly universal medium: a film made in the U.S., for example, can play in theaters the world over. This universality, however, had its downside.

To forestall compatibility problems after a decade of theaters racing to install differing sound equipment and filmmakers rushing "talkies" into production, in the late 1930s the film industry adopted a standardized theater playback response that today is called the "Academy" characteristic. While this resulted in a relatively uniform system of recording and playback that made it possible for just about any film to sound acceptable in any theater in the world, it lacked the flexibility to incorporate improvements beyond the limitations that existed in the 1930s. Indeed, well into the 1970s conventional optical sound reproduction in film theatres had a frequency response little wider than a telephone's.

Upon investigation, Dolby found that the many of the limitations in optical sound stemmed directly from its significantly high background noise. Essentially to filter this noise, the high-frequency response of theater playback systems was deliberately curtailed (the "Academy" characteristic). To make matters worse, in order to increase dialogue intelligibility over such systems, sound mixers were recording soundtracks with so much high-frequency pre-emphasis that high distortion resulted.