5.1 surround sound ("five-point one") is the common name for surround sound audio systems. 5.1 is the most commonly used layout in home theatres.It uses five full bandwidth channels and one low-frequency effects channel (the "point one"). Dolby Digital, Dolby Pro Logic II, DTS, SDDS, and THX are all common 5.1 systems. 5.1 is also the standard surround sound audio component of digital broadcast and music.
All 5.1 systems use the same speaker channels and configuration, having a front left and right, a center channel, two surround channels (left and right) and the low-frequency effects channel designed for a subwoofer.
A prototype for five-channel surround sound, then dubbed "quintaphonic sound", was used in the 1975 film Tommy .
5.1 dates back to 1976, mm film, notably in 1979 with Apocalypse Now . Instead of the five screen channels and one surround channel of the Todd-AO format, Dolby Stereo 70 mm Six Track provided three screen channels, two high-passed surround channels and a low-frequency surround channel monophonically blended with the two surround channels.when Dolby Labs modified the track usage of the six analogue magnetic soundtracks on Todd-AO 70 mm film prints. The Dolby application of optical matrix encoding in 1976 (released on the film Logan's Run ) did not use split surrounds, and thus was not 5.1. Dolby first used split surrounds with 70
When digital sound was applied to 35 mm release prints, with Batman Returns in 1992, the 5.1 layout was adopted. The ability to provide 5.1 sound had been one of the key reasons for using 70 mm for prestige screenings. The provision of 5.1 digital sound on 35 mm significantly reduced the use of the very expensive 70 mm format. Digital sound and the 5.1 format were introduced in 1990, by KODAK and Optical Radiation Corporation, with releases of Days of Thunder and The Doors using the CDS (Cinema Digital Sound) format.
5.1 digital surround, in the forms of Dolby Digital AC3 and DTS, started appearing on several mid-'90s LaserDisc releases, among the earliest being Clear and Present Danger and Jurassic Park (the latter having both AC3 and DTS versions). Many DVD releases have Dolby Digital tracks up to 5.1 channels, due to the implementation of Dolby Digital in the development of the DVD format. In addition, some DVDs have DTS tracks with most being 5.1 channel mixes (a few releases, however, have 6.1 “matrixed” or even discrete 6.1 tracks). Blu-ray and digital cinema both have eight-channel capability which can be used to provide either 5.1 or 7.1 surround sound. 7.1 is an extension of 5.1 that uses four surround zones: two at the sides and two at the back.
A system of digital 5.1 surround sound has also been used in 1987 at the Parisian cabaret the Moulin Rouge, created by French engineer Dominique Bertrand. To achieve such a system in 1985 a dedicated mixing console had to be designed in cooperation with Solid State Logic, based on their 5000 series, and dedicated speakers in cooperation with APG.The console included ABCDEF channels. Respectively: A left, B right, C centre, D left rear, E right rear, F bass. The same engineer had already developed a similar 3.1 system in 1973, for use at the official International Summit of Francophone States in Dakar.
The order of channels in a 5.1 file is different across file formats. The order in WAV files is (not complete) Front Left, Front Right, Center, Low-frequency effects, Surround Left, Surround Right.
In music, the main goal of 5.1 surround sound is a proper localization and equability of all acoustic sources for a center-positioned audience. Therefore, ideally five matched speakers should be used.
For playback of 5.1 music, the International Telecommunication Union (ITU) recommends the following configuration (ITU-R BS 775):
70 mm film is a wide high-resolution film gauge for motion picture photography, with negative area nearly 3.5 times as large as the standard 35 mm motion picture film format. As used in cameras, the film is 65 mm (2.6 in) wide. For projection, the original 65 mm film is printed on 70 mm (2.8 in) film. The additional 5 mm are for four magnetic strips holding six tracks of stereophonic sound. Although later 70 mm prints use digital sound encoding, the vast majority of existing and surviving 70 mm prints pre-date this technology.
Sony Dynamic Digital Sound is a cinema sound system developed by Sony, from which compressed digital sound information is recorded on both outer edges of the 35 mm film release print. The system supports up to eight independent channels of sound: five front channels, two surround channels and a single sub-bass channel. The eight channel arrangement is similar to large format film magnetic sound formats like Cinerama and Cinemiracle. The five front channels are useful for very large cinema auditoriums where the angular distance between center and left/right channels may be considerable. SDDS decoders provide the ability to downmix to fewer channels if required.
Dolby Digital, originally synonymous with Dolby AC-3, is the name for what has now become a family of audio compression technologies developed by Dolby Laboratories. Originally named Dolby Stereo Digital until 1995, except for Dolby TrueHD, the audio compression is lossy, based on the modified discrete cosine transform (MDCT) algorithm. The first use of Dolby Digital was to provide digital sound in cinemas from 35 mm film prints; today, it is now also used for applications such as TV broadcast, radio broadcast via satellite, digital video streaming, DVDs, Blu-ray discs and game consoles.
Home cinema, also called home theaters or theater rooms, are home entertainment audio-visual systems that seek to reproduce a movie theater experience and mood using consumer electronics-grade video and audio equipment that is set up in a room or backyard of a private home. Some studies show films are rated better and generate more intense emotions when watched in a movie theater, however, convenience is a major appeal for home cinemas. In the 1980s, home cinemas typically consisted of a movie pre-recorded on a LaserDisc or VHS tape; a LaserDisc or VHS player; and a heavy, bulky large-screen cathode ray tube TV set, although sometimes CRT projectors were used instead. In the 2000s, technological innovations in sound systems, video player equipment and TV screens and video projectors have changed the equipment used in home cinema set-ups and enabled home users to experience a higher-resolution screen image, improved sound quality and components that offer users more options. The development of Internet-based subscription services means that 2016-era home theatre users do not have to commute to a video rental store as was common in the 1980s and 1990s
Quadraphonic sound – equivalent to what is now called 4.0 surround sound – uses four audio channels in which speakers are positioned at the four corners of a listening space. The system allows for the reproduction of sound signals that are independent of one another.
WinDVD is a commercial video player and music player software for Microsoft Windows. It enables the viewing of DVD-Video movies on the user's PC. DVD-Video backups stored on hard disk can also be played. The player can also be used to play videos and audio/music files in other formats encoded with different codecs, for instance DivX, Xvid, Windows Media Video video and MP3 and AAC audio. Newer versions also support full Blu-ray Disc and HD DVD playback with menus, with CPRM DRM support.
Surround sound is a technique for enriching the fidelity and depth of sound reproduction by using multiple audio channels from speakers that surround the listener. Its first application was in movie theaters. Prior to surround sound, theater sound systems commonly had three "screen channels" of sound that played from three loudspeakers located in front of the audience. Surround sound adds one or more channels from loudspeakers to the side or behind the listener that are able to create the sensation of sound coming from any horizontal direction around the listener.
The low-frequency effects (LFE) channel is a band-limited audio track that is used for reproducing deep and intense low-frequency sounds in the 3–120 Hz frequency range.
Dolby Pro Logic is a surround sound processing technology developed by Dolby Laboratories, designed to decode soundtracks encoded with Dolby Surround.
Dolby Laboratories, Inc. is an American company specializing in audio noise reduction and audio encoding/compression. Dolby licenses its technologies to consumer electronics manufacturers.
A movie projector is an opto-mechanical device for displaying motion picture film by projecting it onto a screen. Most of the optical and mechanical elements, except for the illumination and sound devices, are present in movie cameras. Modern movie projectors are specially built video projectors.
DTS, Inc. is an American company that makes multichannel audio technologies for film and video. Based in Calabasas, California, the company introduced its DTS technology in 1993 as a competitor to Dolby Laboratories, incorporating DTS in the film Jurassic Park (1993). The DTS product is used in surround sound formats for both commercial/theatrical and consumer-grade applications. It was known as The Digital Experience until 1995. DTS licenses its technologies to consumer electronics manufacturers.
Dolby Stereo is a sound format made by Dolby Laboratories. There are two basic Dolby Stereo systems: the Dolby SVA 1976 system used with optical sound tracks on 35mm film, and Dolby Stereo 70mm which refers to Dolby noise reduction on 6-channel magnetic soundtracks on 70mm prints.
7.1 surround sound is the common name for an eight-channel surround audio system commonly used in home theatre configurations. It adds two additional speakers to the more conventional six-channel (5.1) audio configuration. As with 5.1 surround sound, 7.1 surround sound positional audio uses the standard front left and right, center, and LFE (subwoofer) speaker configuration. However, whereas a 5.1 surround sound system combines both surround and rear channel effects into two channels, a 7.1 surround system splits the surround and rear channel information into four distinct channels, in which sound effects are directed to left and right surround channels, plus two rear surround channels.
Dolby TrueHD is a lossless, multi-channel audio codec developed by Dolby Laboratories for home video, used principally in Blu-ray Disc and compatible hardware. Dolby TrueHD, along with Dolby Digital Plus and Dolby AC-4, is one of the intended successors to the Dolby Digital (AC-3) lossy surround format. Dolby TrueHD competes with DTS's DTS-HD Master Audio, another lossless surround sound codec.
An audio/video receiver (AVR) is a consumer electronics component used in a home theater. Its purpose is to receive audio and video signals from a number of sources, and to process them and provide power amplifiers to drive loudspeakers and route the video to displays such as a television, monitor or video projector. Inputs may come from a satellite receiver, radio, DVD players, Blu-ray Disc players, VCRs or video game consoles, among others. The AVR source selection and settings such as volume, are typically set by a remote controller.
Cinema Digital Sound (CDS) was a multi-channel surround sound format used for theatrical films in the early 1990s. The system was developed by Eastman Kodak and Optical Radiation Corporation. CDS was quickly superseded by Digital Theatre Systems (DTS) and Dolby Digital formats.
Megasound was the name of a movie theater sound system created by Warner Bros. and was officially deployed during the early 1980s. Warner Bros. used it to provide deep-bass enhancement to premiere engagements for a handful of their features, including:
Center channel refers to an audio channel common to many surround sound formats. It is the channel that is mostly, or fully, dedicated to the reproduction of the dialogue of an audiovisual program. The speaker(s) connected to the center channel are placed in the center of and behind the perforated projection screen, to give the effect that sounds from the center channel are coming from the screen. In many home surround sound units, the center channel is positioned above or below the video screen.
In sound recording and reproduction, audio mixing is the process of optimizing and combining multitrack recordings into a final mono, stereo or surround sound product. In the process of combining the separate tracks, their relative levels are adjusted and balanced and various processes such as equalization and compression are commonly applied to individual tracks, groups of tracks, and the overall mix. In stereo and surround sound mixing, the placement of the tracks within the stereo field are adjusted and balanced. Audio mixing techniques and approaches vary widely and have a significant influence on the final product.