High fidelity
Encyclopedia
High fidelity—or hi-fi—reproduction is a term used by home stereo listeners and home audio
enthusiasts (audiophile
s) to refer to high-quality reproduction of sound or images
, to distinguish it from the poorer quality sound produced by inexpensive audio equipment. Ideally, high-fidelity equipment has minimal amounts of noise
and distortion
and an accurate frequency response
.
One effort to standardize the term was the 1966 German Deutsches Institut für Normung
(DIN) standard DIN 45500. DIN 45 500 approval was intended to provide audio equipment buyers with reassurance that their equipment was capable of good quality reproduction. In theory, only stereo equipment that met the standard could bear the words 'hi-fi'. This standard was well intentioned but only mildly successful; in practice, the term was widely misapplied to audio products that did not remotely approach the DIN basis specifications.
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.
After World War II
, several innovations created the conditions for a major improvement of home-audio quality:
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 33⅓ 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, preamplifier
s, 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 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. 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.
. A subject is presented with two known samples (sample A, the reference, and sample B, an alternative), and one unknown sample X, for three samples total. X is randomly selected from A and B, and the subject identifies X as being either A or B. Although there is no way to prove that a certain lossy methodology is transparent
, a properly conducted double-blind test can prove that a lossy method is not transparent.
Scientific double-blind tests are often used to disprove certain audio components (such as expensive, exotic cables) have any real bearings on audible sound quality. These tests are not accepted by some "audiophile" magazines in their evaluation of audio equipment, such as Stereophile
and The Absolute Sound
. John Atkinson (editor), current editor of Stereophile, stated (in a 2005 July editorial named Blind Tests & Bus Stops) that he once purchased a solid-state amplifier, the Quad 405, in 1978 after blind tests, but came to realize months later that "the magic was gone" until he replaced it with a tube amp. Robert Harley of The Absolute Sound wrote, in a 2008 editorial (on Issue 183), that "blind listening tests fundamentally distort the listening process and are worthless in determining the audibility of a certain phenomenon."
Doug Schneider, editor of the online Soundstage network, refuted this position with two editorials in 2009. He stated: "Blind tests are at the core of the decades’ worth of research into loudspeaker design done at Canada’s National Research Council (NRC). The NRC researchers knew that for their results to be credible within the scientific community and to have the most meaningful results, they had to eliminate bias, and blind testing was the only way to do so." Many Canadian companies such as Axiom, Energy, Mirage, Paradigm, PSB and Revel use blind testing extensively in designing their loudspeakers. Many audio insiders like Sean Olive of Harman International share this view.
of live orchestral performers by creating a phantom middle channel when the listener sits exactly in the middle of the two front loudspeakers. 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 quadraphonic sound but, again, the technology at that time was insufficient for the task. Consumers did not want to pay the additional costs and space required for the marginal improvements in realism. With the rise in popularity of home theatre
, however, multi-channel playback systems became affordable, and many consumers were willing to tolerate the six to eight channels required in a home theater. 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.
In addition to spatial realism, the playback of music must be subjectively free from noise to achieve realism. The compact disc
(CD) provides about 90 decibel
s of dynamic range
, which is about as much as most people can tolerate in an average living room
.
Audio equipment must be able to reproduce frequencies high enough and low enough to be realistic. The human hearing range, for healthy young persons, is 20 Hz to 20,000 Hz.
Most adults can't hear higher than 15 kHz. CDs are capable of reproducing frequencies as low as 10 Hz and as high as 22.05 kHz, making them adequate, in range, to reproduce all the frequencies that people can hear.
The equipment must also provide no noticeable distortion of the signal or emphasis or de-emphasis of any frequency in this frequency range.
s or minisystems, 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. Such products are generally disparaged by audiophile
s, although some high-end manufacturers do produce integrated systems. The traditional hi-fi enthusiast, however, will build a system from separates (or components), 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 upgrade
s, a preamplifier
and a power amplifier
in one box is called an integrated amplifier
; with a tuner, it is a receiver
. 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, turntable
s, Digital Media Players, digital audio players, DVD
players that play a wide variety of discs including CDs, CD recorders, MiniDisc
recorders, hi-fi videocassette recorder
s (VCRs) and reel-to-reel
tape recorder
s. Signal modification equipment can include equalizers
and signal processor
s.
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. Some of the disadvantages of this approach are increased cost, complexity, and space required for the components.
(DAT), digital audio broadcasting
(DAB) or HD Radio
tuners. Some modern hi-fi equipment can be digitally connected using fibre optic TOSLINK
cables, universal serial bus (USB) ports (including one to play digital audio files), or Wi-Fi
support.
Another modern component is the music server consisting of one or more computer
hard drives
that hold music in the form of computer file
s. When the music is stored in an audio file format
that is lossless such as FLAC
, Monkey's Audio
or WMA Lossless, the computer playback of recorded audio can serve as an audiophile-quality source for a hi-fi system.
Home audio
Home audio, essentially, refers to any audio electronics intended for home use, such as shelf stereos and surround sound receivers, which are becoming the most popular piece of home audio equipment...
enthusiasts (audiophile
Audiophile
An audiophile is a person who enjoys listening to recorded music, usually in a home. Some audiophiles are more interested in collecting and listening to music, while others are more interested in collecting and listening to audio components, whose "sound quality" they consider as important as the...
s) to refer to high-quality reproduction of sound or images
Video
Video is the technology of electronically capturing, recording, processing, storing, transmitting, and reconstructing a sequence of still images representing scenes in motion.- History :...
, to distinguish it from the poorer quality sound produced by inexpensive audio equipment. Ideally, high-fidelity equipment has minimal amounts of noise
Noise
In common use, the word noise means any unwanted sound. In both analog and digital electronics, noise is random unwanted perturbation to a wanted signal; it is called noise as a generalisation of the acoustic noise heard when listening to a weak radio transmission with significant electrical noise...
and distortion
Distortion
A distortion is the alteration of the original shape of an object, image, sound, waveform or other form of information or representation. Distortion is usually unwanted, and often many methods are employed to minimize it in practice...
and an accurate frequency response
Frequency response
Frequency response is the quantitative measure of the output spectrum of a system or device in response to a stimulus, and is used to characterize the dynamics of the system. It is a measure of magnitude and phase of the output as a function of frequency, in comparison to the input...
.
One effort to standardize the term was the 1966 German Deutsches Institut für Normung
Deutsches Institut für Normung
is the German national organization for standardization and is that country's ISO member body. DIN is a Registered German Association headquartered in Berlin...
(DIN) standard DIN 45500. DIN 45 500 approval was intended to provide audio equipment buyers with reassurance that their equipment was capable of good quality reproduction. In theory, only stereo equipment that met the standard could bear the words 'hi-fi'. This standard was well intentioned but only mildly successful; in practice, the term was widely misapplied to audio products that did not remotely approach the DIN basis specifications.
History
Bell Laboratories began experimenting with wider range recording techniques in the early 1930s. Performances by Leopold StokowskiLeopold Stokowski
Leopold Anthony Stokowski was a British-born, naturalised American orchestral conductor, well known for his free-hand performing style that spurned the traditional baton and for obtaining a characteristically sumptuous sound from many of the great orchestras he conducted.In America, Stokowski...
and the Philadelphia Orchestra
Philadelphia Orchestra
The Philadelphia Orchestra is a symphony orchestra based in Philadelphia, Pennsylvania, in the United States. One of the "Big Five" American orchestras, it was founded in 1900...
were recorded in 1931 and 1932, using telephone lines between the Academy of Music
Academy of Music
Academy of Music may refer to:* Academy of Music , Maryland* Academy of Music in Budapest, Hungary* Academy of Music in Manhattan** A second Academy of Music in Manhattan, renamed the Palladium...
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.
After World War II
World War II
World War II, or the Second World War , was a global conflict lasting from 1939 to 1945, involving most of the world's nations—including all of the great powers—eventually forming two opposing military alliances: the Allies and the Axis...
, several innovations created the conditions for a major improvement of home-audio quality:
- Reel-to-reel audio tape recordingReel-to-reel audio tape recordingReel-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 securely contained within a cassette....
, based on technology found in Germany after the war, helped musical artists such as Bing CrosbyBing CrosbyHarry Lillis "Bing" Crosby was an American singer and actor. Crosby's trademark bass-baritone voice made him one of the best-selling recording artists of the 20th century, with over half a billion records in circulation....
make and distribute recordings with better fidelity. - The advent of the 33⅓ rpm Long Play (LP) microgroove vinyl record, with low surface noise and quantitatively-specified equalization curvesRIAA equalizationRIAA equalization is a specification for the correct recording of gramophone records, established by the Recording Industry Association of America...
. Classical musicClassical musicClassical music is the art music produced in, or rooted in, the traditions of Western liturgical and secular music, encompassing a broad period from roughly the 11th century to present times...
fans, who were opinion leadersOpinion leadershipOpinion leadership is a concept that arises out of the theory of two-step flow of communication propounded by Paul Lazarsfeld and Elihu Katz. This theory is one of several models that try to explain the diffusion of innovations, ideas, or commercial products....
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 amplifierElectronic amplifierAn electronic amplifier is a device for increasing the power of a signal.It does this by taking energy from a power supply and controlling the output to match the input signal shape but with a larger amplitude...
designs, with more attention to frequency response and much higher power output capability, allowing audio peaks to be reproduced without distortionDistortionA distortion is the alteration of the original shape of an object, image, sound, waveform or other form of information or representation. Distortion is usually unwanted, and often many methods are employed to minimize it in practice...
.
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 33⅓ 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, preamplifier
Preamplifier
A preamplifier is an electronic amplifier that prepares a small electrical signal for further amplification or processing. A preamplifier is often placed close to the sensor to reduce the effects of noise and interference. It is used to boost the signal strength to drive the cable to the main...
s, 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 very popular type of system for reproducing music from the 1970s onwards was the integrated music centre
Music centre
A music centre is a type of integrated audio system for home use, used to play from a variety of media. The term is usually used for lower end or sub-high fidelity or hi fi equipment. The term itself has been in use since the 1970s, though in more recent times the terms mini, micro or midi hi-fi,...
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 the individual components. Purists generally avoid referring to these systems as high fidelity, though some are capable of very good quality sound reproduction.
Listening tests
Blind tests refer to experiments where researchers have sighted knowledge on the tested (audio) components, but not individuals undergoing the experiments. 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 testABX test
An ABX test is a method of comparing two kinds of sensory stimuli to identify detectable differences. A subject is presented with two known samples , and one unknown sample X, for three samples total. X is randomly selected from A and B, and the subject identifies X as being either A or B...
. A subject is presented with two known samples (sample A, the reference, and sample B, an alternative), and one unknown sample X, for three samples total. X is randomly selected from A and B, and the subject identifies X as being either A or B. Although there is no way to prove that a certain lossy methodology is transparent
Transparency (data compression)
In data compression or psychoacoustics, transparency is the ideal result of lossy data compression. If a lossy compressed result is perceptually indistinguishable from the uncompressed input, then the compression can be declared to be transparent...
, a properly conducted double-blind test can prove that a lossy method is not transparent.
Scientific double-blind tests are often used to disprove certain audio components (such as expensive, exotic cables) have any real bearings on audible sound quality. These tests are not accepted by some "audiophile" magazines in their evaluation of audio equipment, such as Stereophile
Stereophile
Stereophile is a monthly magazine that focuses on high end audio equipment, such as loudspeakers and amplifiers, and audio-related news, such as online audio streaming. It was founded in 1962 by J. Gordon Holt....
and The Absolute Sound
The Absolute Sound
The Absolute Sound is an American monthly magazine which reviews audiophile-oriented sound-reproduction and recording equipment and recordings, and comments on various music-related subjects. It was founded in 1973 by Harry Pearson, who was the Editor in Chief...
. John Atkinson (editor), current editor of Stereophile, stated (in a 2005 July editorial named Blind Tests & Bus Stops) that he once purchased a solid-state amplifier, the Quad 405, in 1978 after blind tests, but came to realize months later that "the magic was gone" until he replaced it with a tube amp. Robert Harley of The Absolute Sound wrote, in a 2008 editorial (on Issue 183), that "blind listening tests fundamentally distort the listening process and are worthless in determining the audibility of a certain phenomenon."
Doug Schneider, editor of the online Soundstage network, refuted this position with two editorials in 2009. He stated: "Blind tests are at the core of the decades’ worth of research into loudspeaker design done at Canada’s National Research Council (NRC). The NRC researchers knew that for their results to be credible within the scientific community and to have the most meaningful results, they had to eliminate bias, and blind testing was the only way to do so." Many Canadian companies such as Axiom, Energy, Mirage, Paradigm, PSB and Revel use blind testing extensively in designing their loudspeakers. Many audio insiders like Sean Olive of Harman International share this view.
Semblance of realism
Stereophonic sound provided a partial solution to the problem of creating some semblance of the illusionAuditory illusion
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, or "impossible" sounds...
of live orchestral performers by creating a phantom middle channel when the listener sits exactly in the middle of the two front loudspeakers. 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 quadraphonic sound but, again, the technology at that time was insufficient for the task. Consumers did not want to pay the additional costs and space required for the marginal improvements in realism. With the rise in popularity of home theatre
Home cinema
Home cinema, also commonly called home theater, are home entertainment set-ups that seek to reproduce a movie theater experience and mood with the help of video and audio equipment in a private home....
, however, multi-channel playback systems became affordable, and many consumers were willing to tolerate the six to eight channels required in a home theater. The advances made in signal processors
Digital signal processor
A digital signal processor is a specialized microprocessor with an architecture optimized for the fast operational needs of digital signal processing.-Typical characteristics:...
to synthesize an approximation of a good concert hall can now provide a somewhat more realistic illusion of listening in a concert hall.
In addition to spatial realism, the playback of music must be subjectively free from noise to achieve realism. The compact disc
Compact Disc
The Compact Disc is an optical disc used to store digital data. It was originally developed to store and playback sound recordings exclusively, but later expanded to encompass data storage , write-once audio and data storage , rewritable media , Video Compact Discs , Super Video Compact Discs ,...
(CD) provides about 90 decibel
Decibel
The decibel is a logarithmic unit that indicates the ratio of a physical quantity relative to a specified or implied reference level. A ratio in decibels is ten times the logarithm to base 10 of the ratio of two power quantities...
s of dynamic range
Dynamic range
Dynamic range, abbreviated DR or DNR, is the ratio between the largest and smallest possible values of a changeable quantity, such as in sound and light. It is measured as a ratio, or as a base-10 or base-2 logarithmic value.-Dynamic range and human perception:The human senses of sight and...
, which is about as much as most people can tolerate in an average living room
Living room
A living room, also known as sitting room, lounge room or lounge , is a room for entertaining adult guests, reading, or other activities...
.
Audio equipment must be able to reproduce frequencies high enough and low enough to be realistic. The human hearing range, for healthy young persons, is 20 Hz to 20,000 Hz.
Most adults can't hear higher than 15 kHz. CDs are capable of reproducing frequencies as low as 10 Hz and as high as 22.05 kHz, making them adequate, in range, to reproduce all the frequencies that people can hear.
The equipment must also provide no noticeable distortion of the signal or emphasis or de-emphasis of any frequency in this frequency range.
Modularity
Integrated, mini, or lifestyle systems, also known as music centreMusic centre
A music centre is a type of integrated audio system for home use, used to play from a variety of media. The term is usually used for lower end or sub-high fidelity or hi fi equipment. The term itself has been in use since the 1970s, though in more recent times the terms mini, micro or midi hi-fi,...
s or minisystems, contain one or more sources such as a CD player
Compact disc player
A Compact Disc player , or CD player, is an electronic device that plays audio Compact Discs. CD players are often a part of home stereo systems, car audio systems, and personal computers. They are also manufactured as portable devices...
, a tuner
Tuner (radio)
A radio tuner is a subsystem that receives radio broadcasts and converts them into audio-frequency signals which can be fed into an amplifier driving a loudspeaker. FM tuner, AM tuner, Digital Audio Broadcasting DAB tuner, etc. are types of radio tuner dealing with transmissions using different...
, or a cassette deck together with a preamplifier
Preamplifier
A preamplifier is an electronic amplifier that prepares a small electrical signal for further amplification or processing. A preamplifier is often placed close to the sensor to reduce the effects of noise and interference. It is used to boost the signal strength to drive the cable to the main...
and a power amplifier in one box. Such products are generally disparaged by audiophile
Audiophile
An audiophile is a person who enjoys listening to recorded music, usually in a home. Some audiophiles are more interested in collecting and listening to music, while others are more interested in collecting and listening to audio components, whose "sound quality" they consider as important as the...
s, although some high-end manufacturers do produce integrated systems. The traditional hi-fi enthusiast, however, will build a system from separates (or components), 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 upgrade
Upgrade
The term upgrade refers to the replacement of a product with a newer version of the same product. It is most often used in computing and consumer electronics, generally meaning a replacement of hardware, software or firmware with a newer or better version, in order to bring the system up to date...
s, a preamplifier
Preamplifier
A preamplifier is an electronic amplifier that prepares a small electrical signal for further amplification or processing. A preamplifier is often placed close to the sensor to reduce the effects of noise and interference. It is used to boost the signal strength to drive the cable to the main...
and a power amplifier
Amplifier
Generally, an amplifier or simply amp, is a device for increasing the power of a signal.In popular use, the term usually describes an electronic amplifier, in which the input "signal" is usually a voltage or a current. In audio applications, amplifiers drive the loudspeakers used in PA systems to...
in one box is called an integrated amplifier
Integrated amplifier
An integrated amplifier is an electronic device containing an audio preamplifier and power amplifier in one unit, as opposed to separating the two. Most modern audio amplifiers are integrated and have several inputs for devices such as CD players, DVD players, and auxiliary sources...
; with a tuner, it is a receiver
Receiver (radio)
A radio receiver converts signals from a radio antenna to a usable form. It uses electronic filters to separate a wanted radio frequency signal from all other signals, the electronic amplifier increases the level suitable for further processing, and finally recovers the desired information through...
. A monophonic power amplifier, which is called a monoblock
Amplifier
Generally, an amplifier or simply amp, is a device for increasing the power of a signal.In popular use, the term usually describes an electronic amplifier, in which the input "signal" is usually a voltage or a current. In audio applications, amplifiers drive the loudspeakers used in PA systems to...
, is often used for powering a subwoofer
Subwoofer
A subwoofer is a woofer, or a complete loudspeaker, which is dedicated to the reproduction of low-pitched audio frequencies known as the "bass". The typical frequency range for a subwoofer is about 20–200 Hz for consumer products, below 100 Hz for professional live sound, and below...
. Other modules in the system may include components like cartridges
Magnetic cartridge
A magnetic cartridge is a transducer used for the playback of gramophone records on a turntable or phonograph. It converts mechanical vibrational energy from a stylus riding in a spiral record groove into an electrical signal that is subsequently amplified and then converted back to sound by a...
, tonearms, turntable
Phonograph
The phonograph record player, or gramophone is a device introduced in 1877 that has had continued common use for reproducing sound recordings, although when first developed, the phonograph was used to both record and reproduce sounds...
s, Digital Media Players, digital audio players, DVD
DVD
A DVD is an optical disc storage media format, invented and developed by Philips, Sony, Toshiba, and Panasonic in 1995. DVDs offer higher storage capacity than Compact Discs while having the same dimensions....
players that play a wide variety of discs including CDs, CD recorders, MiniDisc
MiniDisc
The disc is permanently housed in a cartridge with a sliding door, similar to the casing of a 3.5" floppy disk. This shutter is opened automatically by a mechanism upon insertion. The audio discs can either be recordable or premastered. Recordable MiniDiscs use a magneto-optical system to record...
recorders, hi-fi videocassette recorder
Videocassette recorder
The videocassette recorder , is a type of electro-mechanical device that uses removable videocassettes that contain magnetic tape for recording analog audio and analog video from broadcast television so that the images and sound can be played back at a more convenient time...
s (VCRs) and reel-to-reel
Reel-to-reel audio tape recording
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 securely contained within a cassette....
tape recorder
Tape recorder
An audio tape recorder, tape deck, reel-to-reel tape deck, cassette deck or tape machine is an audio storage device that records and plays back sounds, including articulated voices, usually using magnetic tape, either wound on a reel or in a cassette, for storage...
s. Signal modification equipment can include equalizers
Equalization (audio)
Equalization is the process commonly used in sound recording and reproduction to alter the frequency response of an audio system using linear filters. Most hi-fi equipment uses relatively simple filters to make bass and treble adjustments. Graphic and parametric equalizers have much more...
and signal processor
Signal processor
A signal processor is an electronic circuit that removes information from an analog signal as quantifiable units for further analysis. Most modern signal processors are either dedicated microprocessor integrated circuits or general-purpose programmable microprocessors. A DSP is an electronic...
s.
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. Some of the disadvantages of this approach are increased cost, complexity, and space required for the components.
Modern equipment
Modern hi-fi equipment can include signal sources such as digital audio tapeDigital Audio Tape
Digital Audio Tape is a signal recording and playback medium developed by Sony and introduced in 1987. In appearance it is similar to a compact audio cassette, using 4 mm magnetic tape enclosed in a protective shell, but is roughly half the size at 73 mm × 54 mm × 10.5 mm. As...
(DAT), digital audio broadcasting
Digital audio broadcasting
Digital Audio Broadcasting is a digital radio technology for broadcasting radio stations, used in several countries, particularly in Europe. As of 2006, approximately 1,000 stations worldwide broadcast in the DAB format....
(DAB) or HD Radio
HD Radio
HD Radio, which originally stood for "Hybrid Digital", is the trademark for iBiquity's in-band on-channel digital radio technology used by AM and FM radio stations to transmit audio and data via a digital signal in conjunction with their analog signals...
tuners. Some modern hi-fi equipment can be digitally connected using fibre optic TOSLINK
TOSLINK
TOSLINK is a standardized optical fiber connection system. Also known generically as an "optical audio cable," its most common use is in consumer audio equipment , where it carries a digital audio stream from components such as MiniDisc, CD and DVD players, DAT recorders, computers, and modern...
cables, universal serial bus (USB) ports (including one to play digital audio files), or Wi-Fi
Wi-Fi
Wi-Fi or Wifi, is a mechanism for wirelessly connecting electronic devices. A device enabled with Wi-Fi, such as a personal computer, video game console, smartphone, or digital audio player, can connect to the Internet via a wireless network access point. An access point has a range of about 20...
support.
Another modern component is the music server consisting of one or more computer
Computer
A computer is a programmable machine designed to sequentially and automatically carry out a sequence of arithmetic or logical operations. The particular sequence of operations can be changed readily, allowing the computer to solve more than one kind of problem...
hard drives
Hard disk
A hard disk drive is a non-volatile, random access digital magnetic data storage device. It features rotating rigid platters on a motor-driven spindle within a protective enclosure. Data is magnetically read from and written to the platter by read/write heads that float on a film of air above the...
that hold music in the form of computer file
Computer file
A computer file is a block of arbitrary information, or resource for storing information, which is available to a computer program and is usually based on some kind of durable storage. A file is durable in the sense that it remains available for programs to use after the current program has finished...
s. When the music is stored in an audio file format
Audio file format
An audio file format is a file format for storing digital audio data on a computer system. This data can be stored uncompressed, or compressed to reduce the file size. It can be a raw bitstream, but it is usually a container format or an audio data format with defined storage layer.-Types of...
that is lossless such as FLAC
FLAC
FLAC is a codec which allows digital audio to be losslessly compressed such that file size is reduced without any information being lost...
, Monkey's Audio
Monkey's Audio
Monkey's Audio is a file format for audio data compression. Being a lossless format, Monkey's Audio does not discard data during the process of encoding, unlike lossy compression methods such as AAC, MP3, Vorbis and Musepack....
or WMA Lossless, the computer playback of recorded audio can serve as an audiophile-quality source for a hi-fi system.
See also
- Audio system measurementsAudio system measurementsAudio system measurements are made for several purposes. Designers take measurements so that they can specify the performance of a piece of equipment. Maintenance engineers make them to ensure equipment is still working to specification, or to ensure that the cumulative defects of an audio path are...
- DIY audioDIY audioDIY Audio means "do it yourself" audio. Rather than buying a piece of possibly expensive audio equipment, such as a high-end audio amplifier or speaker, the person practicing DIY Audio will make it him/herself...
- Entertainment CenterEntertainment centerA home entertainment center is a piece of furniture seen in many homes in North America, which houses major electronic items, such as a television set, a VCR and/or DVD player, stereo components , and cable or satellite television receivers...
- High-end audioHigh-end audioHigh-end audio is a term used to describe a class of consumer home audio equipment marketed to audio enthusiasts on the basis of high price or quality, and esoteric or novel sound reproduction technologies. High-end audio can refer simply to the price, to the build quality of the components, or to...
- Low fidelityLow fidelityLow fidelity or lo-fi describes a sound recording which contains technical flaws such as distortion, hum, or background noise, or limited frequency response...
- No FidelityNo-fiNo-Fi is a term used to describe music or media created outside conventional technical standards.-The name:Where "Hi-fi" and "Lo-fi" are short for "High Fidelity" and "Low Fidelity", respectively, "No-fi" is a play-on-words intended to be interpreted as meaning "No Fidelity".-The sound:No-Fi is an...
- Radio Data System (RDS)Radio Data SystemRadio Data System, or RDS, is a communications protocol standard for embedding small amounts of digital information in conventional FM radio broadcasts. RDS standardises several types of information transmitted, including time, station identification and programme information.Radio Broadcast Data...
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