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Ground Lift
In sound recording and reproduction, ground lift or earth lift is a technique used to reduce or eliminate ground-related noise arising from ground loops in audio cables. It may also increase or decrease noise from other sources. Activating the ground lift on a particular piece of equipment opens the connection between the equipment ground and the shielding conductor of audio cables attached to the equipment, leaving those cables grounded only at their opposite end. If all pieces of equipment are tied to a common ground reference without establishing ground loop, no current flows in the ground conductors and cable shields, and no noise is introduced into signal circuits. In applications such as sound reinforcement for a concert, however, it is difficult to ensure all equipment shares a common ground reference. Ground lift switch Professional audio equipment intended for use with balanced lines may have a ground lift switch for the cable shield. The ground lift switch eliminates ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sound Recording And Reproduction
Sound recording and reproduction is the electrical, mechanical, electronic, or digital inscription and re-creation of sound waves, such as spoken voice, singing, instrumental music, or sound effects. The two main classes of sound recording technology are analog recording and digital recording. Sound recording is the transcription of invisible vibrations in air onto a storage medium such as a phonograph disc. The process is reversed in sound reproduction, and the variations stored on the medium are transformed back into sound waves. Acoustic analog recording is achieved by a microphone diaphragm that senses changes in atmospheric pressure caused by acoustic sound waves and records them as a mechanical representation of the sound waves on a medium such as a phonograph record (in which a stylus cuts grooves on a record). In magnetic tape recording, the sound waves vibrate the microphone diaphragm and are converted into a varying electric current, which is then converted to ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ground (electricity)
In electrical engineering, ground or earth is a reference point in an electrical circuit from which voltages are measured, a common return path for electric current, or a direct physical connection to the Earth. Electrical circuits may be connected to ground for several reasons. Exposed conductive parts of electrical equipment are connected to ground, to protect users from electrical shock hazard. If internal insulation fails, dangerous voltages may appear on the exposed conductive parts. Connecting exposed parts to ground will allow circuit breakers (or RCDs) to interrupt power supply in the event of a fault. In electric power distribution systems, a protective earth (PE) conductor is an essential part of the safety provided by the earthing system. Connection to ground also limits the build-up of static electricity when handling flammable products or electrostatic-sensitive devices. In some telegraph and power transmission circuits, the ground itself can be used as one condu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Noise (audio)
Noise is unwanted sound considered unpleasant, loud or disruptive to hearing. From a physics standpoint, there is no distinction between noise and desired sound, as both are vibrations through a medium, such as air or water. The difference arises when the brain receives and perceives a sound. Acoustic noise is any sound in the acoustic domain, either deliberate (e.g., music or speech) or unintended. In contrast, noise in electronics may not be audible to the human ear and may require instruments for detection. In audio engineering, noise can refer to the unwanted residual electronic noise signal that gives rise to acoustic noise heard as a hiss. This signal noise is commonly measured using A-weighting or ITU-R 468 weighting. In experimental sciences, noise can refer to any random fluctuations of data that hinders perception of a signal. Measurement Sound is measured based on the amplitude and frequency of a sound wave. Amplitude measures how forceful the wave is. The ene ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ground Loop (electricity)
In an electrical system, a ground loop or earth loop occurs when two points of a circuit are intended to have the same ground reference potential but instead have a different potential between them. This is typically caused when enough current is flowing in the connection between the two ground points to produce a voltage drop and cause two points to be at different potentials. Current may be produced in a circular ground connection (ground loop) by electromagnetic induction. Ground loops are a major cause of noise, hum, and interference in audio, video, and computer systems. Wiring practices that protect against ground loops include ensuring that all vulnerable signal circuits are referenced to one point as ground. The use of differential signaling can provide rejection of ground-induced interference. Removal of safety ground connections to equipment in an effort to eliminate ground loops also eliminates the protection the safety ground connection is intended to provide. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
XLR Cable Connectors
XLR may refer to: * XLR connector, an electrical connector commonly used in audio equipment * Cadillac XLR, a retractable hardtop convertible automobile * ''Megas XLR'', an American animated television series * X-linked recessive inheritance * XLR-8 XLR-8 (pronounced "accelerate") was a suspended roller coaster located at the defunct Six Flags AstroWorld. Manufactured by Arrow Huss at a cost of $3.2 million, the ride opened to the public in 1984, where it operated until the park's closure i ..., a roller coaster * XL programming language runtime See also * {{dab ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sound Reinforcement System
A sound reinforcement system is the combination of microphones, signal processors, amplifiers, and loudspeakers in enclosures all controlled by a mixing console that makes live or pre-recorded sounds louder and may also distribute those sounds to a larger or more distant audience. In many situations, a sound reinforcement system is also used to enhance or alter the sound of the sources on the stage, typically by using electronic effects, such as reverb, as opposed to simply amplifying the sources unaltered. A sound reinforcement system for a rock concert in a stadium may be very complex, including hundreds of microphones, complex live sound mixing and signal processing systems, tens of thousands of watts of amplifier power, and multiple loudspeaker arrays, all overseen by a team of audio engineers and technicians. On the other hand, a sound reinforcement system can be as simple as a small public address (PA) system, consisting of, for example, a single microphone connected to ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Balanced Line
In telecommunications and professional audio, a balanced line or balanced signal pair is a circuit consisting of two conductors of the same type, both of which have equal impedances along their lengths and equal impedances to ground and to other circuits. The chief advantage of the balanced line format is good rejection of common-mode noise and interference when fed to a differential device such as a transformer or differential amplifier.G. Ballou, ''Handbook for Sound Engineers'', Fifth Edition, Taylor & Francis, 2015, p. 1267–1268. As prevalent in sound recording and reproduction, balanced lines are referred to as balanced audio. Common forms of balanced line are twin-lead, used for radio frequency signals and twisted pair, used for lower frequencies. They are to be contrasted to unbalanced lines, such as coaxial cable, which is designed to have its return conductor connected to ground, or circuits whose return conductor actually is ground (see earth-return telegraph). Bal ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
XLR Connector
The XLR connector is a type of electrical connector primarily used in professional audio, video, and stage lighting equipment. XLR connectors are cylindical in design, and have three to seven connector pins, and are often employed for analog balanced audio interconnections, AES3 digital audio, portable intercom, DMX512 lighting control, and for low-voltage power supply. XLR connectors are included to the international standard for dimensions, IEC 61076-2-103. The XLR connector is superficially similar to the smaller DIN connector, with which it is physically incompatible. History and manufacturers The XLR connector (also Cannon plug and Cannon connector) was invented by James H. Cannon, founder of the Cannon Electric company, Los Angeles, California. The XLR connector originated from the ''Cannon X'' series of connectors in 1915; by 1950, a latching mechanism was added to the connector, which produced the ''Cannon XL'' model of connector, and by 1955, the female connector ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Audio Engineering Society
The Audio Engineering Society (AES) is a professional body for engineers, scientists, other individuals with an interest or involvement in the professional audio industry. The membership largely comprises engineers developing devices or products for audio, and persons working in audio content production. It also includes acousticians, audiologists, academics, and those in other disciplines related to audio. The AES is the only worldwide professional society devoted exclusively to audio technology. Established in 1948, the Society develops, reviews and publishes engineering standards for the audio and related media industries, and produces the AES Conventions, which are held twice a year alternating between Europe and the US. The AES and individual regional or national ''sections'' also hold ''AES Conferences'' on different topics during the year. History The idea of a society dedicated solely to audio engineering had been discussed for some time before the first meeting, but was ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cheater Plug
A cheater plug, AC ground lifter or three-prong/two-prong adapter is an adapter that allows a NEMA connector, NEMA 5-15P Ground (electricity), grounding-type AC power plugs and sockets, plug (three prongs) to connect to a AC_power_plugs_and_sockets#NEMA_1-15_.2815_A.2F125_V_ungrounded.29, NEMA 1-15R non-grounding receptacle (two slots). They are needed to allow appliances with 3-wire power cords to plug into legacy ungrounded (two slot) receptacles found in older buildings. The use of such an adapter avoids the need to replace receptacles, but is potentially hazardous if the grounding tab is not connected to electrical ground. These adapters are illegal in some jurisdictions, in particular throughout Canada. A safer and more reliable alternative identified in the US and Canadian electrical codes is to replace the outlet with a Ground Fault Circuit Interrupter (GFCI) breaker outlet. Cheater plugs are also used to break Ground loop (electricity), ground loops in audio systems. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Leslie Harvey
Leslie Cameron Harvey (13 September 1944 – 3 May 1972) was a Scottish guitarist in several bands of the late 1960s and early 1970s, most notably Stone the Crows. He was the brother of Alex Harvey. Biography Harvey was born in Govan, Glasgow. In the 1960s, he was asked to join the Animals by Alan Price but chose to stay with his brother in the Alex Harvey Soul Band. He later joined the Blues Council, another Scottish band. The Blues Council made one record, ''Baby Don't Look Down''. In March 1965, their tour van crashed, killing vocalist Fraser Calder and bassist James Giffen, and the rest of the band went their separate ways. In 1969, Harvey joined Scottish band Cartoone to record some tracks for their second album. He also accompanied Cartoone on their live tour of the United States supporting Led Zeppelin. They also supported the US band Spirit in 1969. John Lee Hooker, whose songs both Harvey and Cartoone used to cover on their tour of the UK, was their opening act. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Keith Relf
William Keith Relf (22 March 194312 May 1976) was an English musician, best known as the lead vocalist and harmonica player for rock band the Yardbirds. He then formed the band Renaissance with his sister Jane Relf, The Yardbirds ex-drummer Jim McCarty and ex-The Nashville Teens keyboardist John Hawken. Early life Relf was born in the Richmond Institution on 22 March 1943 to Mary Elsie Relf (née Vickers) and William Arthur Percy Relf. Keith had a sister Jane. His father was a builder, while his mother stayed at home. Musical career Relf started playing in bands around the summer of 1956 as a singer, guitarist, and harmonica player. His blues harp and vocals were as key to the Yardbirds' sound and success as were the group's three superstar lead guitarists Eric Clapton, Jeff Beck, and Jimmy Page. Relf co-wrote many of the original Yardbirds songs ("Shapes of Things", "I Ain't Done Wrong", "Over Under Sideways Down", "Happenings Ten Years Time Ago"), later showing a leaning ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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