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Wow (recording)
Wow is a relatively slow form of flutter (pitch variation) that can affect gramophone records and tape recorders. For both, the collective expression wow and flutter is commonly used. Gramophone records When playing gramophone records, wow is a once-per-revolution pitch variation that could result from warping of the record or from a pressing plate that was not precisely centered. If the grooves are not centered exactly relative to the spindle hole, the linear velocity of the stylus, instead of dropping gradually as the groove spirals towards the center, varies every revolution to be too high (resulting in a higher pitch) when the stylus is further out, and too low when the stylus is further inwards (resulting in a lower pitch). The more eccentric the positioning, the greater the pitch variation. The cause for "wow"-effects on a warped disc is basically the same: a variation in the linear velocity of the stylus relative to the disc. This can be by either radial warping (sim ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Digital Signal Processing
Digital signal processing (DSP) is the use of digital processing, such as by computers or more specialized digital signal processors, to perform a wide variety of signal processing operations. The digital signals processed in this manner are a sequence of numbers that represent Sampling (signal processing), samples of a continuous variable in a domain such as time, space, or frequency. In digital electronics, a digital signal is represented as a pulse train, which is typically generated by the switching of a transistor. Digital signal processing and analog signal processing are subfields of signal processing. DSP applications include Audio signal processing, audio and speech processing, sonar, radar and other sensor array processing, spectral density estimation, statistical signal processing, digital image processing, data compression, video coding, audio coding, image compression, signal processing for telecommunications, control systems, biomedical engineering, and seismology ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Wow And Flutter Measurement
Measurement of wow and flutter is carried out on audio tape machines, cassette recorders and players, and other analog recording and reproduction devices with rotary components (e.g. movie projectors, turntables (vinyl recording), etc.) This measurement quantifies the amount of 'frequency wobble' (caused by speed fluctuations) present in subjectively valid terms. Turntables tend to suffer mainly ''slow wow''. In digital systems, which are locked to crystal oscillators, variations in clock timing are referred to as wander or jitter, depending on speed. While the terms ''wow'' and ''flutter'' used to be used separately (for wobbles at a rate below and above 4 Hz respectively), they tend to be combined now that universal standards exist for measurement which take both into account simultaneously. Listeners find flutter most objectionable when the actual frequency of wobble is 4 Hz, and less audible above and below this rate. This fact forms the basis for the weighting cur ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Phonograph
A phonograph, later called a gramophone, and since the 1940s a record player, or more recently a turntable, is a device for the mechanical and analogue reproduction of sound. The sound vibration Waveform, waveforms are recorded as corresponding physical deviations of a helical or spiral groove engraved, etched, incised, or impressed into the surface of a rotating cylinder or disc, called a ''Phonograph record, record''. To recreate the sound, the surface is similarly rotated while a playback #Stylus, stylus traces the groove and is therefore vibrated by it, faintly reproducing the recorded sound. In early acoustic phonographs, the stylus vibrated a Diaphragm (acoustics), diaphragm that produced sound waves coupled to the open air through a flaring Horn loudspeaker, horn, or directly to the listener's ears through stethoscope-type earphones. The phonograph was invented in 1877 by Thomas Edison; its use would rise the following year. Alexander Graham Bell's Volta Laboratory an ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rumble Measurement
A rumble is a continuous deep, resonant sound, such as the sound made by heavy vehicles or thunder. In the context of Sound recording and reproduction, audio reproduction rumble refers to a low frequency sound from the Bearing (mechanical), bearings inside a turntable. This is most noticeable in low quality turntables with ball bearings. Higher quality turntables use slide bearings, minimizing rumble. Some phono pre-amplifiers implement a rumble filter, in an attempt to remove the noise. A heavier platter can also help dampen this. Rumble measurement is carried out on turntables (for vinyl recordings) which tend to generate very low frequency noise originating from the centre Bearing (mechanical), bearing and from drive pulleys or belts, as well as from irregularities in the vinyl record, record disc itself. It can be heard as low-frequency noise and becomes a serious problem when playing records on audio systems with a good low-frequency response. Even when not audible, rumble ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pitch Control
A variable speed pitch control (or vari-speed) is a control on an audio device such as a turntable, tape recorder, or CD player that allows the operator to deviate from a standard speed (such as 33, 45 or even 78 rpm on a turntable), resulting in adjustments in pitch. The latter term "vari-speed" is more commonly used for tape decks, particularly in the UK. Analog pitch controls vary the voltage being used by the playback device; digital controls use digital signal processing to change the playback speed or pitch. A typical DJ deck allows the pitch to be increased or reduced by up to 8%, which is achieved by increasing or reducing the speed at which the platter rotates. Turntable or CD playing speed may be changed for beatmatching and other DJ techniques, while pitch shift using a pitch control has myriad uses in sound recording. Vari-speed in consumer cassette decks Superscope, Inc. of Sun Valley added vari-speed as a feature of portable cassette decks in 1975. The C ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Celemony
Celemony Software GmbH is a German musical software company that specializes in digital audio pitch correction software. It produces Melodyne, a popular audio pitch modification tool similar to Auto-Tune, although the program itself is manual tuning software. History Celemony was founded in October 2000 by Peter Neubäcker, Prof. Dr. Hildegard Sourgens and Carsten Gehle. It is based in Munich, Germany. In 2009, Melodyne won an MIPA Award for Most innovative product. In 2011, Celemony released Capstan, a stand-alone audio restoration software that eliminates wow and flutter from digital recordings. In October 2011, Celemony and PreSonus introduced Audio Random Access (ARA), an extension for audio plug-in formats like AU and VST that permits to exchange data between them which is supported by several DAWs. Celemony received a Special Merit/ Technical Grammy Award at the 54th Grammy Awards in February 2012 for "contributions of outstanding technical significance to the rec ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Capstan (software)
Celemony Software GmbH is a German musical software company that specializes in digital audio pitch correction software. It produces Melodyne, a popular audio Pitch correction, pitch modification tool similar to Auto-Tune, although the program itself is manual tuning software. History Celemony was founded in October 2000 by Peter Neubäcker, Prof. Dr. Hildegard Sourgens and Carsten Gehle. It is based in Munich, Germany. In 2009, Melodyne won an MIPA Award for Most innovative product. In 2011, Celemony released Capstan, a stand-alone audio restoration software that eliminates wow and flutter from digital recordings. In October 2011, Celemony and PreSonus introduced Audio Random Access (ARA), an extension for audio plug-in formats like Audio Units, AU and Virtual Studio Technology, VST that permits to exchange data between them which is supported by several Digital audio workstation, DAWs. Celemony received a Special Merit/Technical Grammy Award at the 54th Grammy Awards in Fe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Timebase Correction
Time base correction (TBC) is a technique to reduce or eliminate errors caused by mechanical instability present in analog recordings on mechanical media. Without time base correction, a signal from a videotape recorder (VTR) or videocassette recorder (VCR), cannot be Vision mixer, mixed with other, more time-stable devices such as character generators and video cameras found in television studios and post-production facilities. Time base correction counteracts errors by buffering the video signal as it comes off the videotape at an unsteady rate, and releasing it after a delay at a steady rate. A sync generator provides the timing reference for all devices in the system. By adjusting the delay using a waveform monitor, the corrected signal can be made to match the timing of the other devices in the system. If all of the devices in a system are adjusted so their signals meet the video switcher at the same time and at the same rate, the signals can be mixed. Though external TBCs ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Flutter (electronics And Communication)
In electronics and communication, flutter is the rapid variation of signal parameters, such as amplitude, phase, and frequency. Examples of electronic flutter are: *Rapid variations in received signal levels, such as variations that may be caused by atmospheric disturbances, antenna movements in a high wind, or interaction with other signals. *In radio propagation, a phenomenon in which nearly all radio signals that are usually reflected by ionospheric layers in or above the E-region experience partial or complete absorption. *In radio transmission, rapidly changing signal levels, together with variable multipath time delays, caused by reflection and possible partial absorption of the signal by aircraft flying through the radio beam or common scatter volume. *The variation in the transmission characteristics of a loaded telephone line caused by the action of telegraph direct currents on the loading coils. *In recording and reproducing equipment, the deviation of freque ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Videotape
Videotape is magnetic tape used for storing video and usually Sound recording and reproduction, sound in addition. Information stored can be in the form of either an analog signal, analog or Digital signal (signal processing), digital signal. Videotape is used in both video tape recorders (VTRs) and, more commonly, videocassette recorders (VCRs) and camcorders. Videotapes have also been used for storing scientific or medical data, such as the data produced by an electrocardiogram. Because video signals have a very high Bandwidth (signal processing), bandwidth, and Tape head, stationary heads would require extremely high tape speeds, in most cases, a helical scan, helical-scan video head rotates against the moving tape to record the data in two dimensions. Tape is a Linear motion, linear method of storing information and thus imposes delays to access a portion of the tape that is not already against the heads. The early 2000s saw the introduction and rise to prominence of high-q ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Stiction
Stiction (a portmanteau of the words '' static'' and ''friction'') is the force that needs to be overcome to enable relative motion of stationary objects in contact. Any solid objects pressing against each other (but not sliding) will require some threshold of force parallel to the surface of contact in order to overcome static adhesion. Stiction is a ''threshold'', not a continuous force. However, stiction might also be an illusion made by the rotation of kinetic friction. In situations where two surfaces with areas below the micrometer scale come into close proximity (as in an accelerometer), they may adhere together. At this scale, electrostatic and/or Van der Waals and hydrogen bonding forces become significant. The phenomenon of two such surfaces being adhered together in this manner is also called stiction. Stiction may be related to hydrogen bonding or residual contamination. Automobiles Stiction is also the same threshold at which a rolling object would begin to slide ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
