Dynaquad Channels Surround Sound
Dynaquad, or DY, was a matrix decoder 4-channel quadraphonic sound system developed by Dynaco in 1969. The system originally had four speakers that were arranged in a diamond shape (centre-front, centre-left, centre-rear, centre-right). Initially (first available in 1969 with th ''Dynaco SCA-80Q'' amplifier ), it was introduced as a derived (2:2:4) four channel "decoding" system based on the Hafler circuit, where the back channels played ambient sounds recovered from standard stereo sounds. As such it wasn't used initially used as an encoding method (a similar approach was used on the Electrovoice Stereo-4 system). Commercial usage A simpler form of Dynaquad was adopted, allowing an easy adaptation of existing home setups. The two forward speakers remain in their normal positions, with the user only needing to add two similarly positioned back speakers, forming a square (front-left, front-right, back-left, back-right). Four channel record pioneers Vanguard Records started to ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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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]   |
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Quadraphonic Sound
Quadraphonic (or quadrophonic and sometimes quadrasonic) 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 (wholly or in part) independent of one another. Four channel quadraphonic surround sound can be used to recreate the highly realistic effect of a three-dimensional live concert hall experience in the home. It can also be used to enhance the listener experience beyond the directional limitations of ordinary two channel stereo sound. Quadraphonic audio was the earliest consumer product in surround sound. Since it was introduced to the public in the early 1970s many thousands of quadraphonic recordings have been made. Quadraphonic sound was a commercial failure when first introduced due to a variety of technical issues and format incompatibilities. Four channel audio formats can be more expensive t ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Dynaco
Founded by David Hafler and Ed Laurent in Philadelphia, Pennsylvania in 1955, Dynaco was an American hi-fi audio system manufacturer popular in the 1960s and 1970s for its wide range of affordable, yet high quality audio components..Dunn, Greg, Dynaco Company History', retrieved 8 August 2011 Its best known product was the ST-70 tube stereo amplifier. They also manufactured other tube and solid state amplifiers, preamplifiers, radio tuners and bookshelf loudspeakers. Dynaco was liquidated in 1980, and the trademark is now owned by Radial Engineering Ltd. Early company history In 1950 David Hafler and Herb Keroes started a Philadelphia-based company called Acrosound to build and sell audio-quality output transformers, primarily for home electronics hobbyists. The two men refined and developed the ultra-linear audio circuit pioneered by British audio electronics engineer Alan Blumlein, using taps from the output transformer to feed signal back into the output stage screen grid ci ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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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]   |
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Electrovoice
Electro-Voice (EV) is an American manufacturer of audio equipment, including microphones, amplifiers, and loudspeakers, focused on pro audio applications such as sound reinforcement. As a subdivision of Robert_Bosch_GmbH, Bosch Communications Systems Inc. since 2006, Electro-Voice markets products for use by consumers as well as small or large concert venues, broadcasting, houses of worship, and in retail situations. History On September 1, 1927, Lou Burroughs and Albert R. Kahn began a small business called Radio Engineers, servicing radio Receiver (radio), receivers in the basement of the Century Tire and Rubber Company in South Bend, Indiana. Because of the Great Depression, according to Kahn, “We found ourselves insolvent to the extent of $5,000” ($ today). They decided to focus their business on audio products. The company designed a PA system for Notre Dame football coach Knute Rockne. Rockne, who had difficulty being heard at football practices due to health problems th ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Stereo-4 Stereo-4, also known as EV (from Electro-Voice) or EV-4, was a matrix 4-channel quadraphonic sound system developed in 1970 by Leonard Feldman and Jon Fixler. The system was heavily promoted by RadioShack stores in the United States, and some record companies released LP albums encoded in this format. It was the first commercial quadraphonic sound system for LP records. Development The original EV system was compatible with the Dynaquad DY system, and is related to Sansui's QS Regular Matrix system. T |