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Hafler Circuit
The Hafler circuit is a passive electronics circuit with the aim of getting derived surround sound or ambiophony from regular stereo recordings without using costly electronics. Such circuits are generally known as matrix decoders. The Dynaquad system works using similar principles. Named after its early proponent audio engineer David Hafler, the circuit exploits the high amount of stereo separation between Left and Right channels and sound phase. This type of system is called ''2:2:4'', since the rear channels are simulated from a two-channel stereo track, with no actual extra tracks encoded. The rear channels will playback out of phase sounds, while the forward channels are unaffected. Using the circuit typically reduces stereo separation by only about 2 dB and the rear speakers are only required to reproduce a limited frequency range (allowing them to be smaller and cheaper). Operation The rear sound level in a live performance recorded in stereo is reproduced abou ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Surround Sound
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 (surround channels). 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 (left, center, and right) 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 (at ground level) around the listener. The technique enhances the perception of sound spatialization by exploiting sound localization: a listener's ability to identify the location or origin of a detected sound in direction and distance. This is achieved by using multiple discrete audio channels routed to an array of loudspeakers. Surround sound typically has a listener location ( sweet ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Quatravox
Realistic is a brand produced by RadioShack, a division of Tandy Corporation, to market audio and video products for home use. The brand name was phased out in the mid 1990s and discontinued in 2000, then returned briefly in 2016. History The brand began in 1954 under the name ''realist'', but was subsequently changed due to a prior camera trademark, Stereo Realist. The company's most notable products under the Realistic brand included the extensive line of TRC series Citizens Band radio transceivers, which dominated the CB Radio market during the 1970s, and included the Navaho series of CB base station units. A 1977 motion picture entitled '' Handle with Care'' was sponsored at the time by Tandy Corporation, in part to showcase the line. Also notable were their 8-track tape recorders under the TR- model line and their compact cassette decks under the SCT- model line. They are also the company responsible for the Realistic Mach speaker line. A very wide range of products was mark ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Octophonic Sound
Octophonic sound is a form of audio reproduction that presents eight discrete audio channels using eight speakers. For playback, the speakers may be positioned in a circle around the listeners or in any other configuration. Typical speaker configurations are eight spaced on a circle by 45° (oriented with first speaker 0° or at 22.5°), or the vertices of a cube to create a double quadraphonic set-up with elevation. In reference to his own work, Karlheinz Stockhausen made a distinction between these two forms, reserving the term "octophonic" for a cube configuration, as found in his '' Oktophonie'' and the electronic music for scene 2 and the Farewell of ''Mittwoch aus Licht'', and using the expression "eight-channel sound" for the circular arrangement, as used in ''Sirius'', '' Unsichtbare Chöre'', or Hours 13 to 21 of the '' Klang'' cycle. While quadraphonic sound uses four speakers positioned in a square at the four corners of the listening space (either on the ground or rai ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Multitrack Recording
Multitrack recording (MTR), also known as multitracking or tracking, is a method of sound recording developed in 1955 that allows for the separate recording of multiple sound sources or of sound sources recorded at different times to create a cohesive whole. Multitracking became possible in the mid-1950s when the idea of simultaneously recording different audio channels to separate discrete "tracks" on the same reel-to-reel tape was developed. A "track" was simply a different channel recorded to its own discrete area on the tape whereby their relative sequence of recorded events would be preserved, and playback would be simultaneous or synchronized. A multitrack recorder allows one or more sound sources to different tracks to be simultaneously recorded, which may subsequently be processed and mixed separately. Take, for example, a band with vocals, guitars, a keyboard, bass, and drums that are to be recorded. The singer's microphone, the output of the guitars and keys, and e ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Matrix Decoder
Matrix decoding is an audio technology where a small number of discrete audio channels (e.g., 2) are decoded into a larger number of channels on play back (e.g., 5). The channels are generally, but not always, arranged for transmission or recording by an encoder, and decoded for playback by a decoder. The function is to allow multichannel audio, such as quadraphonic sound or surround sound to be encoded in a stereo signal, and thus played back as stereo on stereo equipment, and as surround on surround equipment – this is "compatible" multichannel audio. Process Matrix encoding does ''not'' allow one to encode several channels in ''fewer'' channels without losing information: one cannot fit 5 channels into 2 (or even 3 into 2) without losing information, as this loses dimensions: the decoded signals are not independent. The idea is rather to encode something that will both be an acceptable approximation of the surround sound when decoded, and acceptable (or even superior) stereo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Four-channel Compact Disc Digital Audio
Compact Disc recordings contain two channels of 44.1-kHz 16-bit linear Pulse-code modulation, PCM audio. However, creators of the CD originally contemplated a four-channel, or quadraphonic, mode as well. The proprietary Red Book (CD standard), Red Book specification, as published by Sony and Philips, briefly mentions a four-channel mode in its June 1980,"Red Book" Audio CD specification, June 1980, Sony/Philips September 1983,"Red Book" Audio CD specification, September 1983, Sony/Philips and November 1991"Red Book" Audio CD specification, November 1991, Sony/Philips editions. On the first page, it lays out the "Main parameters" of the CD system, including: "Number of channels: 2 and/or 4 simultaneously[*] sampled." The footnote says, "In the case of more than two channels the encoder and decoder diagrams have to be adapted." The Red Book also reserved the first bit of the so-called Q subchannel "control field" to signal the presence of four-channel audio, but did not specify a met ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dolby Pro Logic
Dolby Pro Logic is a surround sound processing technology developed by Dolby Laboratories, designed to decode soundtracks encoded with Dolby Surround. Dolby Stereo (also known as ''Dolby MP'' or ''Dolby SVA'') was developed by Dolby in 1976 for analog cinema sound systems. The format was adapted for home use in 1982 as Dolby Surround when HiFi capable consumer VCRs were introduced. It was further improved with the Dolby Pro Logic decoding system after 1987. The ''Dolby MP Matrix'' was the professional system that encoded four channels of film sound into two. This track used by the ''Dolby Stereo'' theater system on a 35mm optical stereo print and decoded back to the original 4.0 Surround. The same four-channel encoded stereo track was largely left unchanged and made available to consumers as ''"Dolby Surround"'' on home video. However, the original Dolby Surround decoders in 1982 were a simple passive matrix three-channel decoder: L/R and Mono Surround. The surround was li ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Azimuth Co-ordinator
The Azimuth Co-ordinator was the first panning control for a quadraphonic sound system, at that time a new concept. Pink Floyd became the first band to use it in their early shows. The Azimuth Co-ordinator uses four rotary rheostats housed in a large box. The rheostats were converted from their standard 270 degrees rotation to operate over the narrower 90 degree range imposed by the physical constraints of the control lever with the box top aperture. The system was operated using two joysticks, which allowed an audio signal to be panned between up to six loudspeakers placed around the hall. The Azimuth Co-ordinator was operated by keyboardist Rick Wright. As he operated the joystick, the source of the sound moved from speaker to speaker around the auditorium. With the controls in the central position, the sound output would be equal in all speakers. It was constructed by a technical engineer Bernard Speight at EMI’s Abbey Road Studios. The original was stolen after the fi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ambisonics
Ambisonics is a ''full-sphere'' surround sound format: in addition to the horizontal plane, it covers sound sources above and below the listener. Unlike some other multichannel surround formats, its transmission channels do not carry speaker signals. Instead, they contain a speaker-independent representation of a sound field called ''B-format'', which is then ''decoded'' to the listener's speaker setup. This extra step allows the producer to think in terms of source directions rather than loudspeaker positions, and offers the listener a considerable degree of flexibility as to the layout and number of speakers used for playback. Ambisonics was developed in the UK in the 1970s under the auspices of the British National Research Development Corporation. Despite its solid technical foundation and many advantages, Ambisonics had not until recently been a commercial success, and survived only in niche applications and among recording enthusiasts. With the easy availability of power ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Radio Shack
RadioShack, formerly RadioShack Corporation, is an American retailer founded in 1921. At its peak in 1999, RadioShack operated over 8,000 worldwide stores named RadioShack or Tandy Electronics in the United States, Mexico, United Kingdom, Australia, and Canada. Outside of those territories, the company licensed other companies to use the RadioShack brand name in parts of Asia, North Africa, Latin America, and the Caribbean. In February 2015, RadioShack Corporation filed for Chapter 11 protection under United States bankruptcy law after 11 consecutive quarterly losses. By then, it was operating only in the United States and Latin America. In May 2015, General Wireless Inc., an affiliate of Standard General, bought the company's assets, including the RadioShack brand name and related intellectual property, for US$26.2 million. General Wireless Operations Inc. was formed to operate the RadioShack stores, and General Wireless IP Holdings LLC was formed to hold the intellectual p ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Realistic (brand)
Realistic is a brand produced by RadioShack, a division of Tandy Corporation, to market audio and video products for home use. The brand name was phased out in the mid 1990s and discontinued in 2000, then returned briefly in 2016. History The brand began in 1954 under the name ''realist'', but was subsequently changed due to a prior camera trademark, Stereo Realist. The company's most notable products under the Realistic brand included the extensive line of TRC series Citizens Band radio transceivers, which dominated the CB Radio market during the 1970s, and included the Navaho series of CB base station units. A 1977 motion picture entitled '' Handle with Care'' was sponsored at the time by Tandy Corporation, in part to showcase the line. Also notable were their 8-track tape recorders under the TR- model line and their compact cassette decks under the SCT- model line. They are also the company responsible for the Realistic Mach speaker line. A very wide range of products was marke ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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