High fidelity

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Hi-fi
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For other uses, see High fidelity (disambiguation).
"Hi-Fi" redirects here. Not to be confused with Wi-Fi.
Hi-fi speakers are a key component of quality audio reproduction

High fidelity (often shortened to Hi-Fi or HiFi) is the high-quality

human hearing range.[2]

High fidelity contrasts with the lower-quality "

AM radio
, or the inferior quality of sound reproduction that can be heard in recordings made until the late 1940s.

History

78-rpm discs. 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. After World War II, Harry F. Olson conducted an experiment whereby test subjects listened to a live orchestra through a hidden variable acoustic filter. The results proved that listeners preferred high-fidelity reproduction, once the noise and distortion introduced by early sound equipment was removed.[citation needed
]

Beginning in 1948, several innovations created the conditions that made major improvements of home-audio quality possible:

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. Many consumers found the difference in quality compared to the then-standard AM radios and 78-rpm records readily apparent and bought high-fidelity phonographs and 33⅓ LPs such as

power amplifiers
and loudspeakers. Some enthusiasts even assembled their own loudspeaker systems. With the advent of integrated multi-speaker console systems in the 1950s, hi-fi became a generic term for home sound equipment, to some extent displacing phonograph and record player.

In the late 1950s and early 1960s, the development of

solid state (transistorized
) equipment was introduced to the market, subsequently replacing tube equipment as the mainstream technology.

power amplifier
into one unit, and is an example of the "component" approach to assembling a comprehensive sound reproduction system.

In the 1960s, the FTC with the help of the audio manufacturers came up with a definition to identify high-fidelity equipment so that the manufacturers could clearly state if they meet the requirements and reduce misleading advertisements.[4]

A popular type of system for reproducing music beginning in the 1970s was the integrated

music centre
—which combined a phonograph turntable, AM-FM radio tuner, tape player, preamplifier, 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 or be familiar with impedance and power ratings. Purists generally avoid referring to these systems as high fidelity, though some are capable of very good quality sound reproduction.

Audiophiles in the 1970s and 1980s preferred to buy each component separately. That way, they could choose models of each component with the specifications that they desired. In the 1980s, a number of audiophile magazines became available, offering reviews of components and articles on how to choose and test speakers, amplifiers, and other components.

Listening tests

See also: Codec listening test

Listening tests are used by hi-fi manufacturers, audiophile magazines, and

audio engineering researchers and scientists. If a listening test is done in such a way that the listener who is assessing the sound quality of a component or recording can see the components that are being used for the test (e.g., the same musical piece listened to through a tube power amplifier and a solid-state amplifier), then it is possible that the listener's pre-existing biases towards or against certain components or brands could affect their judgment. To respond to this issue, researchers began to use blind tests, in which listeners cannot see the components being tested. A commonly used variant of this test is the ABX test. 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 methodology is transparent,[5]
a properly conducted double-blind test can prove that a method is not transparent.

Blind tests are sometimes used as part of attempts to ascertain whether certain audio components (such as expensive, exotic cables) have any subjectively perceivable effect on sound quality. Data gleaned from these blind tests is not accepted by some audiophile magazines such as Stereophile and The Absolute Sound in their evaluations of audio equipment. John Atkinson, current editor of Stereophile, stated that he once purchased a solid-state amplifier, the Quad 405, in 1978 after seeing the results from blind tests, but came to realize months later that "the magic was gone" until he replaced it with a tube amp.[6] Robert Harley of The Absolute Sound wrote, in 2008, that: "...blind listening tests fundamentally distort the listening process and are worthless in determining the audibility of a certain phenomenon."[7]

Doug Schneider, editor of the online Soundstage network, argued the opposite in 2009.

Canada's National Research Council (NRC). The NRC researchers knew that for their result 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. Audio professional Dr. Sean Olive of Harman International shares this view.[10]

Semblance of realism

Stereophonic sound provided a partial solution to the problem of reproducing the sound of live orchestral performers by creating separation among instruments, the illusion of space, and a phantom central channel. An attempt to enhance reverberation was tried in the 1970s through quadraphonic sound. 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 theater
, however, multi-channel playback systems became popular, and many consumers were willing to tolerate the six to eight channels required in a home theater.

In addition to spatial realism, the playback of music must be subjectively free from noise, such as hiss or hum, to achieve realism. The

signal
or emphasis or de-emphasis of any frequency in this frequency range.

Modularity

Modular components made by Samsung and Harman Kardon, (from the bottom) an audio digital receiver, DVD player, and HD TV receiver
A Sony "midi" hifi from the late 1980s. Despite its appearance mimicking separate components, this is an all-in-one unit featuring a record player, a dual cassette tapedeck, a digital tuner, and an amplifier with integrated equalizer. Other midi systems integrating a CD player were also increasingly common by this point.

Integrated, mini, or lifestyle systems (also known by the older terms

power amplifier
in one box. A limitation of an "integrated" system is that failure of any one component can possibly lead to the need to replace the entire unit, as components are not readily swapped in or out of a system merely by plugging and unplugging cables, and may not even have been made available by the manufacturer to allow piecemeal repairs.

Although some High-end audio manufacturers do produce integrated systems, such products are generally disparaged by audiophiles, who prefer to 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 and repairs.

A preamplifier and a power amplifier in one box is called an

CD recorders, MiniDisc recorders, hi-fi videocassette recorders (VCRs) and reel-to-reel tape recorders. Signal modification equipment can include equalizers and noise-reduction systems
.

This modularity allows the enthusiast to spend as little or as much as they want on a component to suit their specific needs, achieve a desired sound, and add components as desired. Also, failure of any component of an integrated system can render it unusable, while the unaffected components of a modular system may continue to function. A modular system introduces the complexity of cabling multiple components and often having different remote controls for each unit.

Modern equipment

Some modern hi-fi equipment can be digitally connected using

fibre optic TOSLINK cables, 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

WMA Lossless
, the computer playback of recorded audio can serve as an audiophile-quality source for a hi-fi system. There is now a push from certain streaming services to offer hi-fi services.

Streaming services typically have a modified dynamic range and possibly bit rates lower than audiophile standards.[citation needed] Tidal and others have launched a hi-fi tier that includes access to FLAC and Master Quality Authenticated studio masters for many tracks through the desktop version of the player. This integration is also available for high-end audio systems.

See also

References

  1. ^ Hartley, H. A. (1958). "High fidelity". Audio Design Handbook (PDF). New York, New York: Gernsback Library. pp. 7, 200. Library of Congress Catalog Card No. 57-9007. Archived from the original (PDF) on 2009-01-27. Retrieved 2009-08-08. I invented the phrase 'high fidelity' in 1927 to denote a type of sound reproduction that might be taken rather seriously by a music lover. In those days the average radio or phonograph equipment sounded pretty horrible but, as I was really interested in music, it occurred to me that something might be done about it.
  2. ^ "Frequency Response". Hi-FiWorld.co.uk.
  3. ^ David Lander (June–July 2006). "The Buyable Past: Classic Hi-Fi Components". American Heritage. Archived from the original on 2007-02-23.
  4. ^ Lachenbruch, David (1963-03-23). Billboard. Nielsen Business Media, Inc. p. 47.
  5. ISBN 0-521-42408-9
    .
  6. ^ John Atkinson (2005-07-17). "Blind Tests & Bus Stops".
  7. ^ Robert Harley (2008-05-28). "Blind Listening Tests are Flawed: An Editorial". The Absolute Sound. Archived from the original on 2011-09-30. Retrieved 2011-09-29.
  8. ^ Doug Schneider (2009-05-01). "The Misinformed Misleading the Uninformed – A Bit About Blind Listening Tests". GoodSound!. Retrieved 2011-09-29.
  9. ^ Doug Schneider (2009-06-01). "A Bit More About Blind Listening Tests (6/2009)". GoodSound!. Retrieved 2011-09-29.
  10. ^ Dr. Sean Olive (2009-04-09). "The Dishonesty of Sighted Listening Tests". Retrieved 2011-09-29.[self-published source?]
  11. ^
    ISBN 0-596-00856-2
    . Digital audio at 16-bit resolution has a theoretical dynamic range of 96 dB, but the actual dynamic range is usually lower because of overhead from filters that are built into most audio systems." ... "Audio CDs achieve about a 90-dB signal-to-noise ratio." "Most adults can't hear frequencies higher than 15 kHz, so the 44.1 kHz sampling rate of CD audio is more than adequate to reproduce the highest frequencies most people can hear.
  12. ISBN 0-387-28470-2
    .
  13. ^ D'Ambrose, Christoper; Choudhary, Rizwan (2003). Elert, Glenn (ed.). "Frequency range of human hearing". The Physics Factbook. Retrieved 2022-01-22.
  14. ^ Argos Catalogue Autumn/Winter 1986. Argos. 1986. pp. 258–259. Archived from the original on 2020-05-27. Midi Systems [..] Scheider 2500R Remote Control Midi System [..] Amstrad MS-45 Midi System [..] Toshiba S103K Midi System [etc] Alt URL
  15. ^ "Matsui MIDI 47". 14 March 2010.

Further reading

External links

Look up high fidelity, hi-fi, or hifi in Wiktionary, the free dictionary.
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