I know many of us haven’t been in a theater for a while, so I wanted to write this short missive about the underappreciated world of theater sound before my next product design post drops. If this sort of technical nerdery isn’t your thing, I get it. Expect the next post on product development in your inbox next week.
In the early days of movie releases, theaters were largely monaural. The first “surround sound” attempt was Disney’s Fantasia. In the 40s it used a 5 speaker array: 3 in the front and 2 in the rear, with the rear channels stored on a separate reel of film. This system was called Fantasound
, and it didn’t catch on. Fantasound was expensive, and in the end it was only used in two theaters: New York’s Broadway Theater and the Carthay Circle Theater in Los Angeles.
Other attempts were made using multiple magnetic tape channels for multiple tracks of audio (think the scratchy-hissy mess of old cassette tapes), or using two optical “stereo” optical tracks with one track being the main movie audio and the second track just for the “surround effects”. Neither of these solutions worked well or were widely implemented, and so surround sound as an idea faded out of fashion through the 50s.
This would be the status quote to the 70s. Even when a studio made a magnetic 4 or 7 channel audio score for their film, only large theaters would invest in the technology to play back magnetic audio. In fact, many theaters would only have mono optical audio for their big screens! This is the environment where Dolby Stereo launched.