The digital age that we are in today has allowed us to watch films wherever we are on any device from a television set to a computer and smartphone. Still, if you ask people on the street why they still go to the cinema, we bet that one of the most popular answers would be the sound.
While the image can somewhat retain its fidelity when translated to the small screen, even expensive home systems at home cannot reproduce the powerful sound in the film theatre. Today we will tell you more about the various cinematic sound systems and examine their similarities and differences.
Types of Recorded Sound
Before we delve deeper into the exploration of cinematic sound systems, it’s necessary to discuss the different types of recorded sound, so you can better understand the technology. There are three main types of recorded sound – monoaural, stereophonic, and surround.
Monoaural (mono) sound is perhaps the oldest type (though there were attempts to recreate stereo sound in late 19th century) and it was the first to be used in sound cinema, being the standard for (almost) all productions from 1904 till the latter half of the 20th century. Mono sound has a single audio channel and emanates from one position. Around 140,000 films have used mono sound.
Stereophonic (stereo) sound, by contrast, comes from two positions, usually placed on the left and right of the object, and it has two audio channels; when reproduced, the sound is intended to come from two loudspeakers or a set of stereo headphones. Stereo sound is meant to resemble human hearing the most, creating a holistic auditory environment. A little over 45,000 films have stereo sound.
Surround sound was famously introduced by Walt Disney who wanted his now-classic film Fantasia (1940) to fully immerse the viewers in the magical environment. Surround sound uses multiple audio channels to achieve this; Disney’s Fantasound System used five (left, right, front, back, and centre), but nowadays you can find systems with up to 24 audio channels and corresponding speakers, although these ones are only used in television for the 4K and 8K formats; the cinematic standard goes up to 11.1.
Popular Cinematic Sound Systems
In this section, we will discuss the most popular cinematic sound systems from the past and present.
Dolby Stereo
Though now largely unused, the Dolby Stereo was the standard for most film projections from the mid-1970’s until the 1990’s. Inspired by Disney, Dolby developed it in 1976 and it has since been used for over 12,000 films. Dolby Stereo actually refers to two different sound systems Dolby SVA (stereo variable-area) and Dolby Stereo 70mm.
Dolby SVA is the older system which uses 4-channel optical sound tracks on 35mm film, while Dolby Stereo 70mm uses 6-channel magnetic soundtracks on 70mm film.
Dolby also released Dolby Stereo SR in 1986, an improvement of its earlier stereo sound systems. Dolby Stereo SR improves noise reduction and dynamic range. It was used in about 6000 films.
Dolby Digital
Dolby Digital (1991) is the successor to Dolby Stereo; there are multiple sound systems under the umbrella of Dolby Digital. Despite its name, the first Dolby Digital was not used for digital films, instead it produced digital sound in cinemas for features shot on film.
The first reiteration known simply as Dolby Digital uses five audio channels and speakers. Although its classic mode is surround sound, it also provides mono and stereo modes.
In 1999, Dolby introduced two new sound systems – Dolby Digital EX and Dolby Digital Surround EX. Both systems have been used in over 6000 films.
Dolby Digital EX was an improvement to the previous versions, adding another central surround channel and allowing for a 6.1 or 7.1 audio channel output.
Dolby, in partnership with George Lucas’ sound technology company THX, developed Dolby Digital Surround EX. It allowed for 5.1 soundtracks to add a sixth center back surround channel which resulted in better localization of sound effects. The resulting track can be played on 5.1, 6.1 or 7.1 systems.
Dolby Digital Surround EX was famously first used for Lucas’ film Star Wars: The Phantom Menace (1999). The sound system is still used for the DVD versions of Star Wars episodes I-VI.
Dolby Atmos
Dolby Atmos is the youngest Dolby sound system. Released in 2012, Dolby Atmos is a ground-breaking surround sound technology system which creates the impression that sounds are three-dimensional objects by adding height channels. Film theatres use the 9.1 channel-based Dolby Atmos. So far, close to 288 films were made with Dolby Atmos.
DTS
DTS is an American sound technology company, and DTS refers to many different sound systems. In cinema, these are some of their most widely used products – DTS-ES, DTS 70mm, and DTS:X.
DTS-ES (1999) is a surround sound system which has two versions, DTS-ES Discreet 6.1 and DTS-ES Matrix 5.1. The sound system was used in 93 films.
DTS 70mm (1996), similar to Dolby Digital 70mm, is used specifically for 70mm film projection and 6-track surround sound. It was used in 28 films.
DTS:X (2015), similar to Dolby Atmos, is the most advanced product by the company which allows the sound to travel with fluidity as the system is not confined to set channels. The sound is dynamically rendered and based on the number and location of the speakers. So far, 42 films were made with DTS:X.
IMAX
IMAX refers to a system of cameras, film formats, film projectors and film theatres. While there is no IMAX-produced sound system, films have to be played with a specific sound system as the cameras used for IMAX (whether they are IMAX camera or fit for IMAX recording) do not record sound, so they can use more of the image area.
IMAX originally required a 6-channel 35mm magnetic film to be recorded on a film followed locked to the image, working surprisingly similar to the first sound system for spoken word, Vitaphone. Nowadays, IMAX uses a hard drive carrying a single audio file containing all six channels which are then converted to analogue.
In terms of speakers, IMAX uses the advantage of the big film theatre by adding a top centre speaker which cannot be found in non-IMAX theatres.