This is about audiophile sound systems; for other uses, see high fidelity (disambiguation).

High fidelity or hi-fi reproduction is a term used by home stereo listeners and home audio enthusiasts (audiophiles) to refer to high-quality reproduction of sound or images that is very faithful to the original master recording. An audiophile, from Latin audio "I hear" and Greek philos "loving" is an audio reproduction enthusiast who typically listens Video is the technology of electronically capturing, Recording, processing storing transmitting and reconstructing a sequence of Still images High fidelity equipment has minimal or unnoticeable amounts of noise and distortion and an accurate frequency response as set out in 1973 by the German Deutsches Institut für Normung (DIN) standard DIN 45500. is a one volume manga created by Tsutomu Nihei as a prequel to his ten-volume work Blame!. A distortion is the alteration of the original shape (or other characteristic of an object image sound waveform or other form of information or representation Frequency response is the measure of any system's spectrum response at the output to a signal of varying Frequency (but constant amplitude at its input The term was most widely used in this strict sense in the 1950s and 1960s; in subsequent decades, the term was applied more loosely to any mid-level stereo system. In the 2000s, the term "hi-fi" for expensive high quality home audio electronics was largely replaced with the term "high-end audio". High-end audio is a term used to describe higher priced and/or higher quality audio equipment

Contents 1 History 2 Ascertaining high fidelity: double-blind tests 3 Semblance of realism 4 Modularity 5 Modern equipment 6 See also 7 References 8 External links

History

The 1920s saw the introduction of electronic amplification, microphones, and the application of quantitative engineering principles to the reproduction of sound. An electronic amplifier is a device for increasing the power and/or Amplitude of a signal. Much of the pioneering work was done at Bell Laboratories and commercialized by Western Electric. Bell Laboratories (also known as Bell Labs and formerly known as AT&T Bell Laboratories and Bell Telephone Laboratories) is the Research organization Western Electric Company (sometimes abbreviated WE and WECo) was an American Electrical engineering company the manufacturing arm Acoustically-recorded disc records with capriciously peaky frequency response were replaced with electrically recorded records. Acoustics is the interdisciplinary science that deals with the study of Sound, Ultrasound and Infrasound (all mechanical waves in gases liquids and solids A gramophone Frequency response is the measure of any system's spectrum response at the output to a signal of varying Frequency (but constant amplitude at its input The Victor Orthophonic phonograph, although purely acoustic, was created by engineers who applied waveguide technology to the design of the interior folded horn to produce a smooth frequency response which complemented and equalled that of the electrically recorded Victor Orthophonic records. Victrola redirects here For other uses see Victrola (disambiguation The Victor Talking Machine Company ( 1901 – 1929 The phonograph, or gramophone, was the most common device for playing recorded Sound from the 1870s through the 1980s A waveguide is a structure which guides waves such as Electromagnetic waves Light, or Sound waves

Meanwhile, the rise of radio meant increased popularity for loudspeakers and tube amplifiers, so there was an anomaly of a period of time during which radio receivers commonly used loudspeakers and electronic amplifiers to produce sound, while phonographs were still commonly purely mechanical and acoustic. Radio is the transmission of signals by Modulation of electromagnetic waves with frequencies below those of visible Light. For the Marty Friedman album see Loudspeaker (album A loudspeaker, speaker, or speaker system is an electroacoustical A valve ( UK) audio amplifier or vacuum tube ( US) audio amplifier is a Valve amplifier used for sound recording reinforcement or reproduction This article is about a radio receiver for other uses see Radio (disambiguation. Later, electronic phonographs became available, as stand-alone units or designed to play through consumer's radios. The now ubiquitous RCA connector was first introduced by the Radio Corporation of America for this purpose. An RCA jack, also referred to as a phono connector or CINCH/AV connector, is a type of Electrical connector that is commonly used in the audio/video RCA Corporation, founded as Radio Corporation of America, was an electronics company in existence from 1919 to 1986

The development of Sound film in the 1930s led motion picture companies to develop amplification and loudspeaker systems to fill movie theaters with good quality sound at a reasonable volume. A sound film is a motion picture with synchronized sound, or sound technologically coupled to image as opposed to a Silent film. To achieve this result, they employed loudspeakers with separate sections for low and high frequencies ("woofers" and "tweeters"), connected via an audio crossover network, and more carefully engineered enclosures. For the Marty Friedman album see Loudspeaker (album A loudspeaker, speaker, or speaker system is an electroacoustical A tweeter is a Loudspeaker designed to produce high frequencies typically from around 2000 Hertz to 20000 hertz (20000 Hz generally considered to be the upper Audio crossovers are a class of Electronic filters designed specifically for use in audio applications especially Hi-fi. A Loudspeaker enclosure is a cabinet designed to transmit sound to the listener via mounted loudspeaker drive units This development exposed the public to better fidelity than home equipment was capable of at the time. Some movie stars purchased movie theater sound equipment for use in their homes but the cost was out of reach for anyone of modest means.

After World War II, several innovations created the conditions for a major improvement of home-audio quality:

• Reel-to-reel audio tape recording, based on technology found in Germany after the war, helped musical artists such as Bing Crosby make and distribute recordings with better fidelity. World War II, or the Second World War, (often abbreviated WWII) was a global military conflict which involved a majority of the world's nations, including Reel-to-reel, open reel tape recording is the form of magnetic tape audio recording in which the recording medium is held on a Reel, rather than being Harry Lillis “Bing” Crosby ( May 3, 1903 &ndash October 14, 1977) was an Academy Award winning American Popular
• the advent of the 33⅓ RPM Long Play (LP) microgroove vinyl record, with low surface noise and quantitatively-specified equalization curves. A gramophone is a one volume manga created by Tsutomu Nihei as a prequel to his ten-volume work Blame!. RIAA equalization is a specification for the correct playback of Gramophone records established by the Recording Industry Association of America (RIAA 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. Classical music is a broad term that usually refers to mainstream music produced in or rooted in the traditions of Western liturgical and Secular music Opinion leadership is a concept that arose out of the theory of Two-step flow of communication propounded by Paul Lazarsfeld and Elihu Katz.
• FM radio, with wider audio bandwidth and less susceptibility to signal interference and fading than AM radio. See also Frequency modulation, FM band FM broadcasting is a broadcast Technology invented by Edwin Howard Armstrong that
• better amplifier designs, with more attention to frequency response and much higher power output capability, allowing audio peaks to be reproduced without distortion. An electronic amplifier is a device for increasing the power and/or Amplitude of a signal. A distortion is the alteration of the original shape (or other characteristic of an object image sound waveform or other form of information or representation

In the 1950s, the term high fidelity began to be used by audio manufacturers as a marketing term to describe records and equipment which were 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 33 LPs, such as RCA's New Orthophonics and London's ffrrs, 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. A preamplifier (preamp or control amp in some parts of the world is an Electronic amplifier which precedes another amplifier to prepare an electronic Some enthusiasts assembled their own loudspeaker systems. In the 1950s, hi-fi became a generic term, to some extent displacing phonograph and record player. Rather than "playing a record on the phonograph", people would "play it on the hi-fi".

In the late 1950s and early 1960s, the development of the Westrex single-groove stereophonic record led to the next wave of home-audio improvement, and in common parlance, stereo displaced hi-fi. Stereophonic sound, commonly called stereo, is the reproduction of Sound, using two or more independent audio channels through a Symmetrical 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.

A very popular type of system for reproducing music from the 1970s onwards 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. A music centre (or center) is a type of integrated audio system for home use used to play from a variety of media These systems advertised their simplicity; the consumer did not have to select and assemble the individual components. Purists generally avoid referring to these systems as high fidelity, though some are capable of very good quality sound reproduction.

Ascertaining high fidelity: double-blind tests

In a double-blind experiment, neither the individuals nor the researchers know who belongs to the control group and the experimental group. Only after all the data has been recorded (and in some cases, analyzed) do the researchers learn which individuals are which. A commonly-used variant of this test is the ABX test. An ABX test is a method of comparing two kinds of sensory stimuli to identify detectable differences This involves comparing two known audio sources (A and B) with either one of these when it has been randomly selected (X). Despite some objections from some audiophiles, double-blind testing is valid. ^[1]

Semblance of realism

When high fidelity was limited to monophonic sound reproduction, a realistic approximation to what the listener would experience in a concert hall was limited. Monaural (often shortened to mono) sound reproduction is single-channel A concert hall is a cultural building which serves as performance venue chiefly for classical instrumental music Researchers quickly realized that the ideal way to experience music played back on audio equipment was through multiple transmission channels, but the technology was not available at that time. Technology is a broad concept that deals with a Species ' usage and knowledge of Tools and Crafts and how it affects a species' ability to control and adapt It was, for example, discovered that a realistic representation of the separation between performers in an orchestra from an ideal listening position in the concert hall would require at least three loudspeakers for the front channels. An orchestra is an instrumental ensemble, usually fairly large with string brass woodwind sections and possibly a percussion section as well For the reproduction of the reverberation, at least two loudspeakers placed behind or to the sides of the listener were required. Reverberation is the persistence of Sound in a particular space after the original sound is removed

Stereophonic sound provided a partial solution to the problem of creating some semblance of the illusion of performers performing in an orchestra by creating a phantom middle channel when the listener sits exactly in the middle of the two front loudspeakers. Stereophonic sound, commonly called stereo, is the reproduction of Sound, using two or more independent audio channels through a Symmetrical An auditory illusion is an Illusion of hearing, the aural equivalent of an optical illusion the listener hears either sounds which are not present in the stimulus When the listener moves slightly to the side, however, this phantom channel disappears or is greatly reduced. An attempt to provide for the reproduction of the reverberation was tried in the 1970s through quadrophonic sound but, again, the technology at that time was insufficient for the task. Quadraphonic (or quadrophonic) sound &ndash the most-widely-used early term for what is now called 4 Consumers did not want to pay the additional costs required in money and space for the marginal improvements in realism. Consumers refers to individuals or households that use goods and services generated within the economy. Money is anything that is generally accepted as Payment for Goods and services and repayment of Debts. With the rise in popularity of home theatre, however, multi-channel playback systems became affordable, and consumers were willing to tolerate the six to eight channels required in a home theatre. Home cinema, also called home theater, are entertainment systems that seek to reproduce cinema quality video and audio in a private home The advances made in signal processors to synthesize an approximation of a good concert hall can now provide a somewhat more realistic illusion of listening in a concert hall. A digital signal processor ( DSP or DSP micro) is a specialized Microprocessor designed specifically for Digital signal processing, generally

In addition to spatial realism, the playback of music must be subjectively free from noise to achieve realism. Music is an Art form in which the medium is Sound organized in Time. The compact disc (CD) provides at least 90 decibels of dynamic range, which is about as much as most people can tolerate in an average living room. A Compact Disc (also known as a CD) is an Optical disc used to store digital data, originally developed for storing digital audio The decibel ( dB) is a logarithmic unit of measurement that expresses the magnitude of a physical quantity (usually power or intensity relative to Dynamic range is a term used frequently in numerous fields to describe the Ratio between the smallest and largest possible values of a changeable quantity such as in Sound A living room, also known as sitting room, lounge room or lounge (in the United Kingdom and Australia) is a room for entertaining This therefore requires the playback equipment to provide a signal-to-noise ratio of at least 90 decibels. Signal-to-noise ratio (often abbreviated SNR or S/N) is an Electrical engineering concept also used in other fields (such as scientific Measurements Many people can hear up to, at most, 15 kHz and for a few, up to 20 kHz. The hertz (symbol Hz) is a measure of Frequency, informally defined as the number of events occurring per Second. There is relatively little music below 50 Hz, loud bass below 30 Hz is rare, music below 16 Hz is almost non-existent, and music below 5 Hz is probably non-existent. Frequency is a measure of the number of occurrences of a repeating event per unit Time. (Incidentally, the cannons in Telarc's recording of Pyotr Tchaikovsky's 1812 Overture are said to go down to 5 Hz. | NOTE Throughout this article "cannon" is used as BOTH the || singular and plural Pyotr Ilyich Tchaikovsky wrote the Festival Overture "The Year 1812" in E major, Op )

The equipment must also provide no noticeable distortion of the signal or emphasis or de-emphasis of any frequency in this frequency range. In the fields of communications, Signal processing, and in Electrical engineering more generally a signal is any time-varying or spatial-varying quantity Except for spatial realism, good modern equipment can easily satisfy all of these requirements at a relatively moderate cost.

Modularity

Integrated, midi, or lifestyle systems contain one or more sources such as a CD player, a tuner, or a cassette deck together with a preamplifier and a power amplifier in one box. A tuner is an adjustable device which passes one Radio Frequency, or band of frequencies and excludes others by using electrical Resonance. The Compact Cassette, often referred to as audio cassette, cassette tape, cassette, or simply tape, is a Magnetic tape sound A preamplifier (preamp or control amp in some parts of the world is an Electronic amplifier which precedes another amplifier to prepare an electronic Generally an amplifier or simply amp, is any device that changes usually increases the amplitude of a signal. (Midi has no connection with MIDI technology in electronic instruments. MIDI ( Musical Instrument Digital Interface, ˈmɪdi is an industry-standard protocol that enables Electronic musical instruments Computers ) Such products are generally disparaged by audiophiles, although some high-end manufacturers do produce integrated systems. An audiophile, from Latin audio "I hear" and Greek philos "loving" is an audio reproduction enthusiast who typically listens The traditional hi-fi enthusiast, however, will build a system from separates, often with each item from a different manufacturer specialising in a particular component. This provides the most flexibility for piece-by-piece upgrades.

For slightly less flexibility in upgrades, a preamplifier and a power amplifier in one box is called an integrated amplifier; with a tuner, it is a receiver. The term upgrade refers to the replacement of a product with a newer version of that same product however it is most often used in Computing and Consumer electronics An integrated amplifier is an electronic device containing an audio Preamplifier and Amplifier in one unit as opposed to separating the two This article is about a radio receiver for other uses see Radio (disambiguation. A monophonic power amplifier , which is called a monoblock, is often used for powering a subwoofer. Other modules in the system may include components like cartridges, tonearms, turntables, Digital Media Players, DVD players that play a wide variety of discs including CDs, CD recorders, MiniDisc recorders, hi-fi video-cassette recorders (VCRs), reel-to-reel recorders, equalizers, signal processors, and subwoofers. A magnetic cartridge is a Transducer used for the playback of Gramophone records on a turntable or phonograph. DVD (also known as " Digital Versatile Disc " or " Digital Video Disc " - see Etymology)is In Computing, an optical disc drive ( ODD) is a Disk drive that uses Laser light or electromagnetic waves near the Light spectrum A MiniDisc ( MD) is a Magneto-optical disc-based Data storage device initially intended for storage of up to 80 minutes of digitized audio PLEASE BEAR IN MIND THAT THIS IS A GENERAL ARTICLE ABOUT VCRs/VIDEOCASSETTE RECORDERS Reel-to-reel, open reel tape recording is the form of magnetic tape audio recording in which the recording medium is held on a Reel, rather than being This article deals mainly with analog tape recorders for audio applications information on digital recording, recording of video signals, and Equalization (or equalisation, EQ) is the process of changing the frequency envelope of a sound in Audio processing. A subwoofer is a Woofer, or a complete Loudspeaker dedicated to the reproduction of bass audio frequencies, from perhaps 150 Hz down

This modularity allows the enthusiast to spend as little or as much as he wants on a component that suits his specific needs. In a system built from separates, sometimes a failure on one component still allows partial use of the rest of the system. A repair of an integrated system, though, means complete lack of use of the system. Another advantage of modularity is the ability to spend one's money on only a few core components at first and then later add additional components to one's system. Because of all these advantages to the modular way of building a high-fidelity system instead of buying an integrated system, audiophiles almost always assemble their system from separates. Some of the obvious disadvantages of this approach are increased cost, complexity, and space required for the components, not to mention the possibility of introducing noise via the interconnects between components.

Modern equipment

Modern hi-fi equipment usually includes digital audio signal sources such as CD players, Digital Audio Tape (DAT) and Digital Audio Broadcasting (DAB) or HD Radio tuners, an amplifier, and loudspeakers. Digital audio uses Digital signals for Sound reproduction. This includes analog-to-digital conversion, digital-to-analog conversion, storage A Compact Disc player (often written as compact disc player) or CD player, is an electronic device which plays audio Compact Discs CD players are often Digital Audio Tape (DAT or R-DAT is a signal recording and playback medium developed by Sony in the mid 1980s Digital Audio Broadcasting ( DAB) also known as Eureka 147, is a Digital radio technology for Broadcasting Radio stations used in HD Radio is the name used by iBiquity for a system of digital transmission for audio broadcast stations Some modern hi-fi equipment can be digitally connected using fiber optic TOSLINK cables, universal serial bus (USB) ports (including one to play digital audio files), or WiFi support. An optical fiber (or fibre) is a Glass or Plastic fiber that carries Light along its length TOSLINK or Optical Cable is a standardized Optical fiber connection system Wi-Fi (ˈwaɪfaɪ is the trade name for the popular wireless technology used

One modern component that is making fast gains in acceptance is the music server consisting of one or more computer hard drives that hold music in the form of computer files. A computer is a Machine that manipulates data according to a list of instructions. A hard disk drive ( HDD) commonly referred to as a hard drive, hard disk, or fixed disk drive, is a Non-volatile storage device A computer file is a block of Arbitrary Information, or resource for storing information which is available to a Computer program and is usually When the music is stored in an audio file format that is lossless (such as FLAC or Monkey Audio), unlike lossy file formats such as MP3, WMA, and Vorbis (which all suffer from fidelity-degradation), the computer playback of recorded audio can indeed serve as an audiophile-quality source for a hi-fi system. An audio file format is a Container format for storing audio data on a Computer system Lossless data compression is a class of Data compression Algorithms that allows the exact original data to be reconstructed from the compressed data Free Lossless Audio Codec ( FLAC) is a File format for lossless Audio data compression. Monkey’s Audio is a File format for Audio data compression. A lossy compression method is one where compressing data and then decompressing it retrieves data that may well be different from the original but is close enough to be useful MPEG-1 Audio Layer 3, more commonly referred to as MP3, is a Digital audio encoding format using a form of Lossy data compression Windows Media Audio ( WMA) is an Audio data compression technology developed by Microsoft. Vorbis is a free and open source, lossy audio Codec project headed by the Xiph However, it should be noted that lossy audio formats are not hi-fi in the stricter sense of the term. Resolutions which exceed CD quality are capable with lossless files and appropriate playback equipment (professional or semipro digital to analog converters).

If the hi-fi system includes components such as a projector, television, satellite decoder, DVD player, surround sound amplification and multi-channel loudspeakers, then it is often called home cinema or a home theatre system. Television ( TV) is a widely used Telecommunication medium for sending ( Broadcasting) and receiving moving Images, either monochromatic This page relates to a Hardware device used to play DVDs For the Apple Software program, see DVD Player (Apple. 51, Multichannel audio, Multichannel music Surround 3D Surround 5 For the Marty Friedman album see Loudspeaker (album A loudspeaker, speaker, or speaker system is an electroacoustical Home cinema, also called home theater, are entertainment systems that seek to reproduce cinema quality video and audio in a private home

See also

• Audio system measurements
• DIY audio
• High-end audio cables
• Low fidelity
• Radio Data System (RDS)

References

External links

• HiFi at the Open Directory Project
• A Dictionary of Home Entertainment Terms
• The High Fidelity Museum

The Open Directory Project ( ODP) also known as dmoz (from directory

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