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High fidelity—or hi-fi or hifi—reproduction is a term used by home stereo listeners and home audio enthusiasts to refer to high-quality reproduction of sound to distinguish it from the poorer quality sound produced by inexpensive audio equipment, or the inferior quality of sound reproduction that can be heard in recordings made until the late 1940s. Ideally, high-fidelity equipment has minimal amounts of noise and distortion and an accurate frequency response. == History == Bell Laboratories began experimenting with wider-range recording techniques in the early 1930s. Performances by Leopold Stokowski and the Philadelphia Orchestra were recorded in 1931 and 1932 using telephone lines between the Academy of Music in Philadelphia and the labs in New Jersey. Some multi-track recordings were made on optical sound film, which led to new advances used primarily by MGM (as early as 1937) and Twentieth Century Fox (as early as 1941). RCA Victor began recording performances by several orchestras on optical sound around 1941, resulting in higher-fidelity masters for 78-rpm discs. Also during the 1930s Avery Fisher, an amateur violinist, began experimenting with audio design and acoustics. He wanted to make a radio that would sound like he was listening to a live orchestra—that would achieve high fidelity to the original sound. Beginning in 1948, several innovations created the conditions for a major improvement of home-audio quality: * Reel-to-reel audio tape recording, based on technology taken from Germany after the war, helped musical artists such as Bing Crosby make and distribute recordings with better fidelity. * The advent of the 33⅓ rpm Long Play (LP) microgroove vinyl record, with lower surface noise and quantitatively specified equalization curves as well as noise-reduction and dynamic range systems. Classical music fans, who were opinion leaders in the audio market, quickly adopted LPs because, unlike with older records, most classical works would fit on a single LP. * FM radio, with wider audio bandwidth and less susceptibility to signal interference and fading than AM radio, though AM could be heard at longer distances at night. * Better amplifier designs, with more attention to frequency response and much higher power output capability, reproducing audio without perceptible distortion.〔(David Lander ) "The Buyable Past: Classic Hi-Fi Components," ''American Heritage'', June/July 2006.〕 In the 1950s, audio manufacturers employed the phrase ''high fidelity'' as a marketing term to describe records and equipment intended to provide faithful sound reproduction. While some consumers simply interpreted ''high fidelity'' as fancy and expensive equipment, many found the difference in quality between "hi-fi" and the then standard AM radios and 78 rpm records readily apparent and bought 33⅓ LPs such as RCA's New Orthophonics and London's ffrr (Full Frequency Range Recording, a UK Decca system); and high-fidelity phonographs. Audiophiles paid attention to technical characteristics and bought individual components, such as separate turntables, radio tuners, preamplifiers, power amplifiers and loudspeakers. Some enthusiasts assembled their own loudspeaker systems. In the 1950s, ''hi-fi'' became a generic term, to some extent displacing ''phonograph'' and ''record player''. In the late 1950s and early 1960s, the development of the Westrex single-groove stereophonic record cutterhead led to the next wave of home-audio improvement, and in common parlance, ''stereo'' displaced ''hi-fi''. Records were now played on ''a stereo''. In the world of the audiophile, however, ''high fidelity'' continued and continues to refer to the goal of highly accurate sound reproduction and to the technological resources available for approaching that goal. This period is most widely regarded as "The Golden Age of Hi-Fi", when tube equipment manufacturers of the time produced many models considered endearing by modern audiophiles, and just before solid state equipment was introduced to the market, subsequently replacing tube equipment as mainstream. A popular type of system for reproducing music beginning in the 1970s was the integrated music centre—which combined phonograph, radio tuner, tape player, preamp, and power amplifier in one package, often sold with its own separate, detachable or integrated speakers. These systems advertised their simplicity. The consumer did not have to select and assemble individual components. Purists generally avoid referring to these systems as high fidelity, though some are capable of very good quality sound reproduction. 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「High fidelity」の詳細全文を読む スポンサード リンク
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