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Quad Electrostatics
The Quad Electrostatic Loudspeaker (ESL) is the world's first production full-range electrostatic loudspeaker, launched in 1957 by Quad Electroacoustics, then known as the Acoustical Manufacturing Co. Ltd. The speaker is shaped somewhat like a home electric radiator curved slightly on the vertical axis. They are widely admired for their clarity and precision, but known to be difficult speakers to run and maintain. The original ESL, in production between 1957 and 1985, has been hailed in '' Sound & Vision'' as one of the most important speakers of the 20th century. It was succeeded in 1981 by the ESL-63, which remained in production until 1999. As of 2013, Quad maintains four electrostatic speakers in its range. History Acoustical Manufacturing Company had launched a ribbon-hybrid, horn-loaded "Corner Ribbon Loudspeaker" in 1949, but this was not commercially successful. The electrostatics were designed by Theo Williamson, and the company's founder, Peter Walker, from a princip ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Quad ESL-57 Luidspreker
QUaD, an acronym for QUEST at DASI, was a ground-based cosmic microwave background (CMB) Polarization (waves), polarization experiment at the South Pole. QUEST (Q and U Extragalactic Sub-mm Telescope) was the original name attributed to the bolometer detector instrument, while Degree Angular Scale Interferometer, DASI is a famous CMB interferometry experiment credited with the first detection of CMB polarization. QUaD used the existing DASI mechanical infrastructure but replaced the DASI interferometric array with a bolometer detector at the end of a Cassegrain reflector, cassegrain optical system. The mount has housed the Keck Array since 2011. See also * Cosmic microwave background radiation * Cosmic microwave background experiments References External links * http://www.stanford.edu/~schurch/quad.html * http://find.spa.umn.edu/quad/ Submillimetre telescopes Radio telescopes Cosmic microwave background experiments Astronomical experiments in the Antarctic {{phy ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Naim NAIT
The Naim NAIT (acronym for "Naim Audio Integrated amplifier") is an integrated amplifier from the British hi-fi manufacturer, Naim Audio. The original NAIT is one of the most recognisable pieces of hi-fi equipment ever made. Hi-fi critic Lucio Cadeddu recognised its legendary status, referring to it as "one of the most controversial and famous integrated amps in the history of HiFi". Having already made their name producing Solid state (electronics), solid-state pre-amplifier and power-amplifier separates, Naim launched a low-powered integrated amplifier that embodies the qualities of Naim Audio amplification, its amplifiers, aimed at cost-conscious audiophiles. Since the NAIT was launched in 1983, it has had six updates. In 2007, Naim released a high end amplifier, the SUPERNAIT. As of 2018, there are three models available- the entry-level the mid-range , and the flagship . History Up to that point a manufacturer of solid-state pre-/power- amplifier separates, Naim Audio w ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Loudspeakers
A loudspeaker (commonly referred to as a speaker or, more fully, a speaker system) is a combination of one or more speaker drivers, an enclosure, and electrical connections (possibly including a crossover network). The speaker driver is an electroacoustic transducer that converts an electrical audio signal into a corresponding sound. The driver is a linear motor connected to a diaphragm, which transmits the motor's movement to produce sound by moving air. An audio signal, typically originating from a microphone, recording, or radio broadcast, is electronically amplified to a power level sufficient to drive the motor, reproducing the sound corresponding to the original unamplified signal. This process functions as the inverse of a microphone. In fact, the ''dynamic speaker'' driver—the most common type—shares the same basic configuration as a dynamic microphone, which operates in reverse as a generator. The dynamic speaker was invented in 1925 by Edward W. Kello ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
LS3/5A
The LS3/5A (each element pronounced separately, without the stroke) is a small studio monitor loudspeaker originated by the BBC for use by outside broadcast vans to ensure quality of their broadcasts. The speaker concept set out transparent and natural sound as the goal, and the achievement of the result is widely acknowledged. The BBC granted licences to a small number of British firms, who first manufactured the product in 1975. The product underwent a change in 1987 due to consistency issues in manufacturing, and again in around 2003 when original parts from KEF ran out. Upwards of 60,000 pairs of the speaker have been sold. Reviewers have recognised its enormous importance as a bookshelf design. History The LS3/5A is a commercially produced loudspeaker driven by the need of the BBC to monitor and assess broadcast programme quality. It was derived from the LS3/5, which was conceived and developed by the BBC Engineering Department in the early 1970s, when it was under the s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Studio Monitor
Studio monitors are loudspeakers in speaker enclosures specifically designed for professional audio production applications, such as recording studios, filmmaking, television studios, radio studios and project or home studios, where accurate audio reproduction is crucial. Among audio engineers, the term ''monitor'' implies that the speaker is designed to produce relatively flat (linear) phase response, phase and frequency responses. In other words, it exhibits minimal emphasis or de-emphasis of particular frequencies, the loudspeaker gives an accurate reproduction of the tonal qualities of the source audio ("uncolored" and "transparent" are synonyms), and there will be no relative absolute phase, phase shift of particular frequencies—meaning no distortion in sound-stage perspective for stereo recordings. Beyond stereo sound-stage requirements, a linear phase response helps impulse response remain true to source without encountering "smearing". An unqualified reference to a ' ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
BBC Listening Room
The British Broadcasting Corporation (BBC) is a British public service broadcaster headquartered at Broadcasting House in London, England. Originally established in 1922 as the British Broadcasting Company, it evolved into its current state with its current name on New Year's Day 1927. The oldest and largest local and global broadcaster by stature and by number of employees, the BBC employs over 21,000 staff in total, of whom approximately 17,200 are in public-sector broadcasting. The BBC was established under a royal charter, and operates under an agreement with the Secretary of State for Culture, Media and Sport. Its work is funded principally by an annual television licence fee which is charged to all British households, companies, and organisations using any type of equipment to receive or record live television broadcasts or to use the BBC's streaming service, iPlayer. The fee is set by the British government, agreed by Parliament, and is used to fund the BBC's radio, TV ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Consumer Electronics Show
CES (; formerly an initialism for Consumer Electronics Show) is an annual trade show organized by the Consumer Technology Association (CTA). Held in January at the Las Vegas Convention Center in Winchester, Nevada, United States, the event typically hosts presentations of new products and technologies in the consumer electronics industry. History The first CES was held in June 1967 in New York City. It was a spin-off of the Chicago Music Show which, until then, had served as the main event for exhibiting consumer electronics. The event had 17,500 attendees and over 100 exhibitors; the kickoff speaker was Motorola chairman Bob Galvin. From 1978 to 1994, CES was held twice each year: once in January in Las Vegas as the ''Winter Consumer Electronics Show'' (WCES) and once in June in Chicago as the ''Summer Consumer Electronics Show'' (SCES). The winter show was held in Las Vegas in 1995 as planned. However, since the summer Chicago shows were beginning to lose popularity, the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sound Pressure Level
Sound pressure or acoustic pressure is the local pressure deviation from the ambient (average or equilibrium) atmospheric pressure, caused by a sound wave. In air, sound pressure can be measured using a microphone, and in water with a hydrophone. The International System of Units, SI unit of sound pressure is the Pascal (unit), pascal (Pa). Mathematical definition A sound wave in a transmission medium causes a deviation (sound pressure, a ''dynamic'' pressure) in the local ambient pressure, a ''static'' pressure. Sound pressure, denoted ''p'', is defined by p_\text = p_\text + p, where * ''p''total is the total pressure, * ''p''stat is the static pressure. Sound measurements Sound intensity In a sound wave, the complementary variable to sound pressure is the particle velocity. Together, they determine the sound intensity of the wave. ''Sound intensity'', denoted I and measured in Watt, W·Metre, m−2 in SI units, is defined by \mathbf I = p \mathbf v, where * ''p'' is th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Extra High Tension
High voltage electricity refers to electrical potential large enough to cause injury or damage. In certain industries, ''high voltage'' refers to voltage above a certain threshold. Equipment and conductors that carry high voltage warrant special safety requirements and procedures. High voltage is used in electrical power distribution, in cathode-ray tubes, to generate X-rays and particle beams, to produce electrical arcs, for ignition, in photomultiplier tubes, and in high-power amplifier vacuum tubes, as well as other industrial, military and scientific applications. Definition The numerical definition of depends on context. Two factors considered in classifying a voltage as high voltage are the possibility of causing a spark in air, and the danger of electric shock by contact or proximity. The International Electrotechnical Commission and its national counterparts (IET, IEEE, VDE, etc.) define ''high voltage'' as above 1000 V for alternating current, and at ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Potential Difference
Voltage, also known as (electrical) potential difference, electric pressure, or electric tension, is the difference in electric potential between two points. In a static electric field, it corresponds to the work needed per unit of charge to move a positive test charge from the first point to the second point. In the International System of Units (SI), the derived unit for voltage is the ''volt'' (''V''). The voltage between points can be caused by the build-up of electric charge (e.g., a capacitor), and from an electromotive force (e.g., electromagnetic induction in a generator). On a macroscopic scale, a potential difference can be caused by electrochemical processes (e.g., cells and batteries), the pressure-induced piezoelectric effect, and the thermoelectric effect. Since it is the difference in electric potential, it is a physical scalar quantity. A voltmeter can be used to measure the voltage between two points in a system. Often a common reference potential su ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Electrostatic Loudspeaker
An electrostatic loudspeaker (ESL) is a loudspeaker design in which sound is generated by the force exerted on a membrane suspended in an electrostatic field. Design and functionality The speakers use a thin flat diaphragm usually consisting of a plastic sheet coated with a conductive material such as graphite sandwiched between two electrically conductive grids, with a small air gap between the diaphragm and grids. For low distortion operation, the diaphragm must operate with a constant charge on its surface, rather than with a constant voltage. This is accomplished by either or both of two techniques: the diaphragm's conductive coating is chosen and applied in a manner to give it a very high surface resistivity, and/or a large value resistor is placed in series between the EHT (Extra High Tension or Voltage) power supply and the diaphragm (resistor not shown in the diagram here). However, the latter technique will still allow distortion as the charge will migrate across the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mylar
BoPET (biaxially oriented polyethylene terephthalate) is a polyester film made from stretched polyethylene terephthalate (PET) and is used for its high tensile strength, chemical stability, dimensional stability, transparency reflectivity, and electrical insulation. When metallized, it has gas and moisture barrier properties. The film is "biaxially oriented", which means that the polymer chains are oriented parallel to the plane of the film, and therefore oriented over two axes. A variety of companies manufacture boPET and other polyester films under different brand names. In the UK and US, the best-known trade names are Mylar, Melinex, Lumirror and Hostaphan. It was the first biaxially oriented polymer to be manufactured on a mass commercial scale. History BoPET film was developed in the mid-1950s,Izard, Emmette Farr"Production of polyethylene terephthalate" U.S. patent no. 2,534,028 (filed: 1948 May 13; issued: 1950 December 12). originally by DuPont, Imperial Chemical ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
