Why is seeing a movie at the cinema is so much more immersive than at home? The giant screen plays a part, as do those delicious sugary treats. But what else is missing? If you said, “well it's due to the surround sound dummy”, firstly you are correct and secondly there is no need for name calling.
Origins
One of the earliest instances of surround sound was in the 1940 Walt Disney film Fantasia. “Disney sound engineer William Garity took separate recordings of each orchestra section and mixed them to produce four distinct audio tracks, which were recorded as optical tracks on a separate reel of film” (Harris, 2001). An additional projector was used to play the soundtrack, with the sound begin sent to 4 speakers throughout the auditorium.
5.1 (baby one in five)
You’ve most likely heard the phrase 5.1 surround sound or seen it written on a DVD (remember those) cover, but what does it mean? Basically “three full-range speakers across the front of the listener, two behind, and a subwoofer” (Robjohns, 2001).
In order to set up a 5.1 speaker system in your own home it is recommended that “the right surround (LS) and left surround (RS) speakers be placed between 100 and 120 degrees with respect to the center front monitor. 110 degrees is a good place to start” (Perry, Dolby vs ITU: The 5.1 & 7.1 Speaker Placement War, 2015).
(Perry, Speaker and Studio Monitor Placement Secrets, 2015)
The Future
Moving past the restrictions of 5.1 and 7.1 (add two speakers behind the listener) set ups, we are now in the era of 3D sound. With 5.1 and 7.1, you can get the sound of something going left to right, but not above and below, losing the immersion factor. This is something Dolby Atmos is rectifying.
“Dolby Atmos had its public debut in the US in June 2012, introduces a ceiling array to the traditional surround speaker configuration and allows object-based sound design for the first time” (Pino, 2019). Sounds are assigned to a space, not a channel, so if sound is heard in the top right-hand corner, it will be spread between the speakers covering that area.
Bibliography
Harris, T. (2001, December 20). How Surround Sound Works. Retrieved from How Stuff Works : https://electronics.howstuffworks.com/surround-sound1.htm
Perry, T. (2015). Dolby vs ITU: The 5.1 & 7.1 Speaker Placement War. Retrieved from Arqen: http://arqen.com/acoustics-101/surround-sound-speaker-placement/
Perry, T. (2015). Speaker and Studio Monitor Placement Secrets. Retrieved from Arqen: http://arqen.com/acoustics-101/room-setup-speaker-placement/
Pino, N. (2019, November 13). Dolby Atmos: The ins, outs and sounds of the object-based surround system. Retrieved from Techradar: https://www.techradar.com/au/news/audio/dolby-atmos-a-step-by-step-guide-to-the-premature-speaker-tech-1305066
Robjohns, H. (2001, November ). Surround Sound Explained: Part 4. Retrieved from SoundonSound: https://www.soundonsound.com/techniques/surround-sound-explained-part-4
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