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Dolby S
A Dolby noise-reduction system (Dolby NR) is one of a series of noise reduction systems developed by Dolby Laboratories for use in analog audio tape recording. The first was Dolby A, a professional broadband noise reduction system for recording studios that was first demonstrated in 1965, but the best-known is Dolby B (introduced in 1968), a sliding band system for the consumer market, which helped make high fidelity practical on cassette tapes, which used a relatively noisy tape size and speed. It is common on high-fidelity stereo tape players and recorders to the present day. Of the noise reduction systems, Dolby A and Dolby SR were developed for professional use. Dolby B, C, and S were designed for the consumer market. Aside from Dolby HX, all the Dolby variants work by companding: compressing the dynamic range of the sound during recording, and expanding it during playback. Process When recording a signal on magnetic tape, there is a low level of noise in the backgroun ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dolby A
A Dolby noise-reduction system (Dolby NR) is one of a series of noise reduction systems developed by Dolby Laboratories for use in analog audio tape recording. The first was Dolby A, a professional broadband noise reduction system for recording studios that was first demonstrated in 1965, but the best-known is Dolby B (introduced in 1968), a sliding band system for the consumer market, which helped make high fidelity practical on cassette tapes, which used a relatively noisy tape size and speed. It is common on high-fidelity stereo tape players and recorders to the present day. Of the noise reduction systems, Dolby A and Dolby SR were developed for professional use. Dolby B, C, and S were designed for the consumer market. Aside from Dolby HX, all the Dolby variants work by companding: compressing the dynamic range of the sound during recording, and expanding it during playback. Process When recording a signal on magnetic tape, there is a low level of noise in the backgrou ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dolby C
A Dolby noise-reduction system (Dolby NR) is one of a series of audio noise reduction, noise reduction systems developed by Dolby Laboratories for use in analog audio tape recording. The first was #Dolby A, Dolby A, a professional broadband noise reduction system for recording studios that was first demonstrated in 1965, but the best-known is #Dolby B, Dolby B (introduced in 1968), a sliding band system for the consumer market, which helped make high fidelity practical on cassette tapes, which used a relatively noisy tape size and speed. It is common on high-fidelity stereo tape players and recorders to the present day. Of the noise reduction systems, Dolby A and #Dolby SR, Dolby SR were developed for professional use. Dolby B, #Dolby C, C, and #Dolby S, S were designed for the consumer market. Aside from #Dolby HX/HX-Pro, Dolby HX, all the Dolby variants work by companding: compressing the dynamic range of the sound during recording, and expanding it during playback. Process W ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dolby B
A Dolby noise-reduction system (Dolby NR) is one of a series of noise reduction systems developed by Dolby Laboratories for use in analog audio tape recording. The first was Dolby A, a professional broadband noise reduction system for recording studios that was first demonstrated in 1965, but the best-known is Dolby B (introduced in 1968), a sliding band system for the consumer market, which helped make high fidelity practical on cassette tapes, which used a relatively noisy tape size and speed. It is common on high-fidelity stereo tape players and recorders to the present day. Of the noise reduction systems, Dolby A and Dolby SR were developed for professional use. Dolby B, C, and S were designed for the consumer market. Aside from Dolby HX, all the Dolby variants work by companding: compressing the dynamic range of the sound during recording, and expanding it during playback. Process When recording a signal on magnetic tape, there is a low level of noise in the backgro ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dolby Stereo
Dolby Stereo is a sound format made by Dolby Laboratories. It is a unified brand for two completely different basic systems: the Dolby SVA (stereo variable-area) 1976 system used with optical sound tracks on 35mm film, and Dolby Stereo 70mm noise reduction on 6-channel magnetic soundtracks on 70mm prints. Dolby SVA significantly improves the development of sound effects in films and theorization of sound design by Walter Murch. In 1982, it was adapted for home use as Dolby Surround when hi-fi capable consumer VCRs were introduced, and further improved in 1987 with the Dolby Pro Logic #Dolby_Surround/Dolby Pro Logic (home decoders), home decoding system. Dolby SVA Of the two, Dolby SVA is by far the more significant, bringing high-quality stereo sound within the reach of virtually every cinema. Though 6-track magnetic stereo had been used in Cinerama films since 1952, and Fox had introduced 4-track stereo magnetic sound as part of the Cinemascope, CinemaScope system in 1953, the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dolby Laboratories
Dolby Laboratories, Inc. (Dolby Labs or simply Dolby) is a British-American technology corporation specializing in audio noise reduction, audio data compression, audio encoding/compression, spatial audio, and high-dynamic-range television (HDR) imaging. Dolby licenses its technologies to consumer electronics manufacturers. History Dolby Labs was founded by Ray Dolby (1933–2013) in London, England, in 1965. In the same year, he invented the Dolby noise-reduction system, Dolby Noise Reduction system, a form of audio signal processing for reducing the background hissing sound on cassette tape recordings. His first U.S. patent on the technology was filed in 1969, four years later. The method was first used by Decca Records in the UK. After this, other companies began purchasing Dolby’s A301 technology, which was the professional noise reduction system used in recording, motion picture, broadcasting stations and communications networks. These companies include BBC, Pye Records ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
VU Meter
A volume unit (VU) meter or standard volume indicator (SVI) is a device displaying a representation of the Signal-to-noise ratio, signal level in audio equipment. The original design was proposed in the 1940 Institute of Radio Engineers, IRE paper, ''A New Standard Volume Indicator and Reference Level'', written by experts from CBS, NBC, and Bell Labs, Bell Telephone Laboratories. The Acoustical Society of America then standardized it in 1942 (ANSI C16.5-1942) for use in telephone installation and radio broadcast stations. Consumer audio equipment often features VU meters, both for utility purposes (e.g. in recording equipment) and for aesthetics (in playback devices). The original VU meter is a passive electromechanical device, namely a 200 μA DC Jacques-Arsène d'Arsonval, d'Arsonval movement ammeter fed from a Metal rectifier, full-wave copper-oxide rectifier mounted within the meter case. The mass of the needle causes a relatively slow response, which in effect Integral, i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Signal-to-noise Ratio
Signal-to-noise ratio (SNR or S/N) is a measure used in science and engineering that compares the level of a desired signal to the level of background noise. SNR is defined as the ratio of signal power to noise power, often expressed in decibels. A ratio higher than 1:1 (greater than 0 dB) indicates more signal than noise. SNR is an important parameter that affects the performance and quality of systems that process or transmit signals, such as communication systems, audio systems, radar systems, imaging systems, and data acquisition systems. A high SNR means that the signal is clear and easy to detect or interpret, while a low SNR means that the signal is corrupted or obscured by noise and may be difficult to distinguish or recover. SNR can be improved by various methods, such as increasing the signal strength, reducing the noise level, filtering out unwanted noise, or using error correction techniques. SNR also determines the maximum possible amount of data that ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Decibel
The decibel (symbol: dB) is a relative unit of measurement equal to one tenth of a bel (B). It expresses the ratio of two values of a Power, root-power, and field quantities, power or root-power quantity on a logarithmic scale. Two signals whose level (logarithmic quantity), levels differ by one decibel have a power ratio of 101/10 (approximately ) or root-power ratio of 101/20 (approximately ). The strict original usage above only expresses a relative change. However, the word decibel has since also been used for expressing an Absolute scale, absolute value that is relative to some fixed reference value, in which case the dB symbol is often suffixed with letter codes that indicate the reference value. For example, for the reference value of 1 volt, a common suffix is "#Voltage, V" (e.g., "20 dBV"). As it originated from a need to express power ratios, two principal types of scaling of the decibel are used to provide consistency depending on whether the scaling refer ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Breathing (noise Reduction)
Noise reduction is the process of removing noise from a signal. Noise reduction techniques exist for audio and images. Noise reduction algorithms may distort the signal to some degree. Noise rejection is the ability of a circuit to isolate an undesired signal component from the desired signal component, as with common-mode rejection ratio. All signal processing devices, both analog and digital, have traits that make them susceptible to noise. Noise can be random with an even frequency distribution (white noise), or frequency-dependent noise introduced by a device's mechanism or signal processing algorithms. In electronic systems, a major type of noise is ''hiss'' created by random electron motion due to thermal agitation. These agitated electrons rapidly add and subtract from the output signal and thus create detectable noise. In the case of photographic film and magnetic tape, noise (both visible and audible) is introduced due to the grain structure of the medium. In photogr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tape Bias
Tape bias is the term for two techniques, AC bias and DC bias, that improve the fidelity of analogue tape recorders. DC bias is the addition of direct current to the audio signal that is being recorded. AC bias is the addition of an inaudible high-frequency signal (generally from 40 to 150 kHz) to the audio signal. Most contemporary tape recorders use AC bias. When recording, magnetic tape has a nonlinear response as determined by its coercivity. Without bias, this response results in poor performance, especially at low signal levels. A recording signal that generates a magnetic field strength less than the tape's coercivity cannot magnetise the tape and produces little playback signal. Bias increases the signal quality of most audio recordings significantly by pushing the signal into more linear zones of the tape's magnetic transfer function. History Magnetic recording was proposed as early as 1878 by Oberlin Smith, who on 4 October 1878 filed, with the U.S. pa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Preemphasis
In signal processing, pre-emphasis is a technique to protect against anticipated noise and loss. The idea is to boost (and hence distort) the frequency range that is most susceptible to noise and loss beforehand, so that after a noisy and lossy process (transmission over cable, tape recording...) more information can be recovered from that frequency range. Removal of the distortion caused by pre-emphasis is called de-emphasis, making the output accurately reproduce the original input. Emphasis is commonly used in many places ranging from FM broadcasting ( preemphasis improvement) and vinyl (e.g. LP) records to PCI Express. For example, high-frequency signal components may be emphasized to produce a more equal modulation index for a transmitted frequency spectrum, and therefore a better signal-to-noise ratio for the entire frequency range. In audio signals In processing electronic audio signals, pre-emphasis refers to a system process designed to increase (within a frequency ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
