1. John M. Eargle

. Store. Doctor ProAudio Online Bookstore Here's a list of books and tools that we have selected for the audio professionals. We make a small commission through 's associates program (you pay the same price), so we'd appreciate if you ordered the items (or anything else that you were going to buy from Amazon anyway) using the links below.

If you do not see an item that you like, use our link to Amazon anyway. Click on the UK or USA flag if you want to buy from Amazon.co.uk or Amazon.com.

Some items may not be available from the UK. Also, remember that Amazon will keep your shopping cart in memory, so if you would like to buy more than one book listed below, click on each product that you want. You can also.

Hi-fi speakers are a key component of quality audio reproduction. High fidelity (often shortened to hi-fi or hifi) reproduction is a term used by home stereo listeners, and enthusiasts to refer to high-quality to distinguish it from the lower 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 inaudible and, and a flat (neutral, uncolored) within the intended frequency range. Contents.

History began experimenting with a wider range of recording techniques in the early 1930s. Performances by and the were recorded in 1931 and 1932 using telephone lines between the in and the Bell labs in New Jersey. Some were made on optical sound film, which led to new advances used primarily by (as early as 1937) and (as early as 1941). Began recording performances by several orchestras using optical sound around 1941, resulting in higher-fidelity masters for 78-rpm discs. During the 1930s, an amateur, began experimenting with audio design and. 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, 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.

• In the debate over tube amps vs. Solid-state amps, Part 1 discussed the differences in applications. Part 2 concentrates on the difference between transistors—MOSFETs and bipolar junctions devices—and vacuum tubes—triodes, tetrodes, and pentodes.
• JBL Audio Engineering for Sound Reinforcement (John Eargle and Chris Foreman) The 29-chapter. Section Two, 'System Components' is concerned with the equipment used, including microphones, consoles, amplifiers, signal processing and loudspeakers. Section Three. Sound Reinforcement Handbook (Gary Davis).

Beginning in 1948, several innovations created the conditions that made for major improvements of home-audio quality possible:., based on technology taken from Germany after WWII, helped musical artists such as make and distribute recordings with better fidelity. The advent of the 33⅓ rpm (LP) microgroove, with lower surface noise and quantitatively specified as well as noise-reduction and dynamic range systems. Fans, who were in the audio market, quickly adopted LPs because, unlike with older records, most classical works would fit on a single LP., with wider audio bandwidth and less susceptibility to signal interference and fading than. Better designs, with more attention to frequency response and much higher power output capability, reproducing audio without perceptible. New designs, including acoustic suspension, developed by and improved bass frequency response. 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 's New Orthophonics and London's ffrr (Full Frequency Range Recording, a UK system); and high-fidelity phonographs. Audiophiles paid attention to technical characteristics and bought individual components, such as separate turntables, radio tuners, and loudspeakers. Some enthusiasts even assembled their own loudspeaker 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 the single-groove 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, the concept of high fidelity continued to refer to the goal of highly accurate sound reproduction and to the technological resources available for approaching that goal.

This period is regarded as the 'Golden Age of Hi-Fi', when equipment manufacturers of the time produced many models considered endearing by modern audiophiles, and just before equipment was introduced to the market, subsequently replacing tube equipment as the mainstream technology. A popular type of system for reproducing music beginning in the 1970s was the integrated —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.

High fidelity reproduction is a term used by home stereo listeners, audiophiles and home audio enthusiasts to refer to high-quality reproduction of sound to distinguish it from the lower quality sound produced by inexpensive audio equipment, or the inferior quality of sound reproduction that can be heard in recordings made.

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 Listening tests are used by hi-fi manufacturers, audiophile magazines and 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, in which the researchers can see the components being tested, but not the listeners undergoing the experiments. In a, neither the listeners nor the researchers know who belongs to the and the, or which type of audio component is being used for which listening sample. Only after all the data has been recorded (and in some cases, analyzed) do the researchers learn which components or recordings were preferred by the listeners. A commonly used variant of this test is the. 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, a properly conducted double-blind test can prove that a method is not transparent.

Scientific double-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 double-blind tests is not accepted by some 'audiophile' magazines such as and in their evaluations of audio equipment., 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 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. 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 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.

Semblance of realism sound provided a partial solution to the problem of creating the 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 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, 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 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, such as hiss or hum, to achieve realism. The (CD) provides about 90 of, which exceeds the 80 dB dynamic range of music as normally perceived in a concert hall. Audio equipment must be able to reproduce frequencies high enough and low enough to be realistic.

John M. Eargle

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 for reproducing the frequency range that most humans can hear.

The equipment must also provide no noticeable distortion of the or emphasis or de-emphasis of any frequency in this frequency range. Modularity. Modular components made by and Integrated, mini, or lifestyle systems, also known as or, contain one or more sources such as a, a, or a deck together with a and a in one box. Although some manufacturers do produce integrated systems, such products are generally disparaged by, 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. For slightly less flexibility in, a and a power in one box is called an; with a tuner, it is a. A monophonic power amplifier, which is called a, is often used for powering a.

Other modules in the system may include components like, hi-fi, players that play a wide variety of discs including, recorders, hi-fi (VCRs) and. Signal modification equipment can include and. This modularity allows the enthusiast to spend as little or as much as they want on a component that suits their 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 money on only a few core components at first and then later add additional components to the system. Some of the disadvantages of this approach are increased cost, complexity, and space required for the components. Modern equipment In the 2000s, modern hi-fi equipment can include signal sources such as (DAT), (DAB) or tuners. Some modern hi-fi equipment can be digitally connected using cables, (USB) ports (including one to play digital audio files), or support. Another modern component is the music server consisting of one or more that hold music in the form of.

When the music is stored in an that is such as, or, the computer playback of recorded audio can serve as an audiophile-quality source for a hi-fi system. See also.

Hartley, H. 'High fidelity'. New York, New York: Gernsback Library. Catalog Card No. 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.

'The Buyable Past: Classic Hi-Fi Components,' American Heritage, June/July 2006. Spanos, Aris (1999). Probability Theory and Statistical Inference. Cambridge University Press.

John Atkinson (2005-07-17). Robert Harley (2008-05-28). The Absolute Sound.

Archived from on 2011-09-30. Retrieved 2011-09-29. Doug Schneider (2009-05-01).

Retrieved 2011-09-29. Doug Schneider (2009-06-01). Retrieved 2011-09-29. Sean Olive (2009-04-09).

Retrieved 2011-09-29. ^ Fries, Bruce; Marty Fries (2005). O'Reilly Media. 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. D'Ambrose, Chris (2003). The Physics Factbook.

Retrieved October 11, 2009. Further reading. Pier Paolo Ferrari, (2016), The Hi-Fi's Golden Age, 1st edition, Bergamo, Italy: Sandit –. Janet Borgerson and Jonathan Schroeder, (2017), Designed for Hi-Fi Living: The Vinyl LP in MIdcentury America. Cambridge, MA: MIT Press – External links. at Curlie (based on ).