Audiophiles try to listen to music at a quality level that is as close to the original performance as possible. They use high-fidelity components to try to attain these goals. Many are music lovers who are passionate about high-quality music reproduction. DIY audio enthusiasts build their own equipment, especially loudspeakers.
Audiophile values may be applied at all stages of music reproduction: the initial audio recording, the production process, and the playback, which is usually in a home setting. High-end audio refers to expensive, high-quality, or esoteric products and practices used in the reproduction of music. Electronic gear used by audiophiles is typically sold at specialist shops. Prices range from not much more than mass market electronics to astronomical heights: high-end audio systems can easily cost more than a new automobile and in extreme cases can be hundreds of thousands of dollars. Most of this gear is produced by companies that specialize in high-end gear, although some also produce equipment used by audio professionals such as by recording studios.
Audiophile magazines include Hi-Fi News, Hi-Fi Choice, Hi-Fi World, and What Hi-Fi? Sound and Vision in the United Kingdom as well as Stereophile and The Absolute Sound in the United States. Hobbyist audio societies also exist: Stereophiles website has a list of such groups in the United States.
Audiophiles can purchase special recordings made with extra attention to sound quality; some companies specialize in re-issuing recordings for this purpose. Many audiophiles feel that vinyl records sound better than compact discs (CDs), and audiophile records are often remastered and pressed on extra-heavy virgin vinyl – 180g or 200g. Audiophiles also collect recordings in the high-resolution formats such as Super Audio CD or DVD-Audio.
In addition, higher quality signal cables (analog audio, speaker, digital audio etc.) are often used to link these components. There may also be a variety of accessories. These may include equalizers, specialized equipment racks, speaker stands, power conditioners, devices to reduce or control vibration, and peripheral devices such as record cleaners, anti-static devices, phonograph needle cleaners, and many others.
The interaction between the loudspeakers and the room plays an important part in sound quality. Sound vibrations are reflected from walls, floor and ceiling, and are affected by the contents of the room. Room dimensions can create standing waves. As a result, audiophiles sometimes design their listening rooms specifically for optimum audio reproduction. There are devices for room treatment that affect sound quality. Soft materials, such as draperies and carpets, reflect high-frequency sound less than hard walls and floors.
In addition to its sound quality, much high-end gear is designed for visual aesthetic appeal as well. Many devices, however, although striking in appearance, do not have universal appeal. They are sometimes large or must occupy specific locations in the listening room, which may be the living room. This leads to the issue humorously known among audiophiles as the wife-acceptance factor (WAF).
As with many hobbies, audiophiles use a certain amount of jargon. This includes a variety of language describing the sound of a system. Examples include bright (excessive energy in the upper frequencies), dark (excessive midbass), or lean (insufficient midbass).
Audiophiles play music from a wide variety of sources such as phonograph records, compact discs (CDs), and digital audio file formats that are uncompressed as well as ones that are compressed using lossless data compression like FLAC, Windows Media Audio 9 Lossless and Apple Lossless. Since the early 1990s, CDs have become the most common source of high-quality music, obliterating the mass market for records. Debate is sharp in this area with analog proponents arguing that analog sound is "warmer" – has a bit of distortion which they find pleasant – and does not suffer from digital sound's alleged loss of audible information in the sampling process, while digital proponents point out that analog formats have a smaller dynamic range, greater deviations in frequency response, and greater distortion which lessens sound quality. Nevertheless, turntables, tonearms, and magnetic cartridges are among the most exotic and lavish high-end audio products despite the difficulties of keeping records free from dust and the delicate set-up associated with turntables.
The 44.1 kHz sampling rate of the CD format, in theory, restricts CD information losses to above the theoretical upper-frequency limit of human hearing – 20 kHz, see Nyquist limit. Some believe, however, that the brick-wall filter used by CD players to remove ultrasonic noise can create audible distortion. Newer formats such as DVD-Audio and Super Audio Compact Disc (SACD), with sampling rates of 96 kHz or higher, have been developed in an attempt to address this criticism.
Despite the popularity of MP3 digital-audio players, some audiophiles criticize these devices because of their reliance on lossy-data compression even though at high bit rates, the resulting files are transparent to most average listeners. In MP3 encoding, musical information is lost in proportion to the degree of compression. Audiophiles who use a digital-audio player will often encode their music at higher bit rates to maintain sound quality at acceptable levels for casual listening. Many digital-audio players, however, can also accept uncompressed formats such as WAV (PCM), foregoing compression in order to retain quality. Some players, including iPods, also allow lossless-data-compression algorithms, which can compress audio files without degrading their sound quality. Popular lossless formats include FLAC, WavPack, Monkey's Audio (APE), Apple Lossless, True Audio, Windows Media Audio 9 Lossless, and Shorten.Although many digital-audio devices have integrated converters, there is a healthy demand for after-market digital-to-analog converters.
Many audiophile systems separate the functions of the preamplifier from that of the power amplifier. A preamplifier selects among several audio inputs, amplifies source-level signals (such as those from a turntable), and allows the listener to adjust the sound with volume and tone controls, switchable filters, etc. A power amplifier takes the "line-level" audio signal from the preamplifier and drives the loudspeakers; typically the only control on a power amplifier is a gain (level) control (or none at all). Some audiophiles use two monophonic power amplifiers in a 'monoblock' configuration rather than one stereophonic power amplifier. Some use no preamplifier, instead connecting a CD player with a variable output directly to a power amplifier. Some go even further and use multiple amplifiers per loudspeaker to drive the woofer, midrange, tweeter, etc. The terms bi-amped and tri-amped are sometimes used to describe these systems. There are, however, those who advocate using integrated amplifiers that combine a preamplifier and power amplifier in one box, arguing the benefits of minimalism.
Audiophile amplifiers are available based on solid-state (semiconductor) technology, vacuum-tube (valve) technology, or hybrid technology - semiconductors and vacuum tubes. Very low power single-ended triode tube amplifiers are often claimed to provide superb sound when paired with appropriately sensitive loudspeakers. On the other hand, there are others who use solid-state amplifiers rated at over 1,000 watts RMS per channel. Some believe that tube amplifiers, despite their much higher distortion, produce a more faithful and detailed reproduction in comparison to solid-state amplifiers. Others respond that this is largely a matter of opinion and personal taste, not proper reproduction of sound. Tube amplifiers, however, are heavily used in music production, primarily in guitar amplifiers because of their soft clipping when overdriven.
Audiophile loudspeakers use a wide variety of technologies and range greatly in size and cost. Starting at prices well under $500 budget audiophile loudspeakers are often the beneficiaries of more advanced technologies developed for higher priced flagship designs. Exotic loudspeaker designs and flagship models are some of the most extreme audiophile components and it is possible to spend more than $100,000 USD on a pair of high-end loudspeakers.
The cabinet the loudspeaker is made from is referred to as the enclosure. There is a wide variety of loudspeaker enclosure designs, including sealed, ported, transmission line, infinite baffle, horn loaded, and aperiodic. The enclosure plays a major role in the sound of the loudspeaker. Loudspeakers designs without enclosures (open baffle or dipole) have been championed by engineers such as Siegfried Linkwitz.
The drivers are the actual sound-producing elements, commonly referred to as tweeters, midranges, woofers, and subwoofers. Driver designs include dynamic, electrostatic, magneplanar, ribbon, planar, ionic, and servo-actuated. Drivers are made from various materials, including paper pulp, polypropylene, kevlar, aluminum, magnesium, beryllium, and vapor-deposited diamond.
The direction and intensity of the output of a loudspeaker, called dispersion or polar response, has a large effect on its sound. Various methods are employed to control the dispersion. These methods include monopolar, bipolar, dipolar, 360 degree, horn, waveguide, and line source. These terms refer to the configuration and arrangement of the various drivers in the enclosure.
The positioning of loudspeakers in the room and of the optimum listening position (referred to as the "sweet spot") is of great importance in producing optimum sound. Loudspeaker output is influenced by interaction with room boundaries, particularly bass response, and high frequency transducers are directional, or "beaming." In addition, audiophiles care a great deal about accurate stereo representation of sound. A typical placement is for the loudspeakers and the listening position to form roughly an equilateral triangle, with the loudspeakers a few feet from the back wall.
Some audiophiles use a wide variety of accessories and fine-tuning techniques, otherwise known as "tweaks," to improve the sound of their systems. These tweaks include: filters to clean the electricity; equipment racks to isolate components from floor vibrations; specialty power cables, interconnect cables (e.g., between preamplifier and power amplifier), and loudspeaker cables; loudspeaker stands (and footers to isolate them from the stands); and room treatments – to name but a few. One also frequently sees an accusation of "bogus accessories" such as CD treatments – edge markers, spray-on cleaners, and destaticizers, about which the assertion has been made that audiophiles who claim to hear an improvement can never identify the treated CD in a blind test.
Room treatments typically consist of sound-absorbing materials placed strategically within a listening room to reduce the amplitude of early reflections, and to adjust resonance modes. Room treatments can be expensive and difficult to optimize, but are considered by many to be the most effective of the many available tweaks.
Another, less expensive, practice of some audiophiles is the use of premium headphones. Most audiophiles-standard headphones retail in the region of $60-$500, although it is possible to spend upwards of $14,000 (e.g. the Sennheiser HE-90). Most headphones marketed to audiophiles are a tiny fraction of the cost of comparable speaker systems and do not require any room adjustment for music enjoyment.Running afoul of community noise regulations or even disturbing roommates can be avoided.Newer canalphones, while as expensive as their larger counterparts, can be driven by less powerful outputs like portable devices.
See main article: Audio equipment testing.
Audiophiles are split into two separate schools of thought regarding testing. Objectivists believe that audio system measurements and double blind testing is of the greatest importance. Subjectivists believe that measured performance can not account for all discernible differences in sound quality and rely on extended listening tests to form an opinion. Some subjectivists do believe that listening discernment should be repeatable and based only on sound, and approve of blind testing.
Even though there is general agreement on the goal, opinions vary widely among designers and listeners on how best to achieve high fidelity. One design principle is minimalism. Given that each step in capturing, storing, and playing back music may degrade it, some audiophiles believe that the fewer and simpler the stages, the better. Many audiophile components, for example, lack tone control circuits, since it is felt that these may degrade the audio quality while moving the sound away from the ideal.
The minimalist subjectivist assertion is that music contains elements which cannot be measured by electronic instruments, so the less one alters the original signal, the more likely it is that this unmeasurable quality is preserved.
Objectivists, however, want to reasonably quantify and specify the effects of input source, amplifier set-up, system power, speaker configuration, etc. on the listening experience. This desire is complementary to purely subjective preferences in quantifying the perceptible effects of different equipment set-ups.
While minimalists strive to keep the signal unmodified from studio rendition to final listener output, a non-minimalist desires the opposite, and attempting to either restore the original environment or, in some cases, enhance the original rendition. DSP algorithms such as real-time mono-to-stereo conversions, Sound Retrieval System (SRS), and Environmental Audio Extensions (EAX) manipulate the signals to enhance listener experience. EAX, for example, can simulate a room environment or simulate a stadium environment by using mathematical acoustical algorithms to add echo or reverb to the signal, taking a rendition of a song and placing it in the simulated environment. For example, a recording could be sent through a DSP algorithm mimicking outdoor echo effects, which would not be present if the recording was captured directly from the instrument or in a studio designed to dampen any acoustical effects. Non-minimalists may also choose to manipulate the sound with an equalizer in order to compensate for resonant room modes as well as to enhance certain frequency ranges that may have been lost during recording or that are not reproduced during playback. Minimalists would argue that these devices alter the natural quality of the sound.
See main article: Analog sound vs. digital sound. Audiophiles differ in opinion over the relative value and performance of digital and analog media. Pro-digital audiophiles believe that digital technology's absence of clicks, pops, wow, flutter, audio feedback, and rumble make it superior to records. They also assert that digital technology has a higher signal-to-noise ratio, has a wider dynamic range, has less total harmonic distortion, and has a flatter and more extended frequency response.  Pro-analog audiophiles believe that analog sound lacks the deleterious effects caused by the analog to digital conversion necessary to produce CDs and therefore analog music reproduction from records played on a properly configured turntable/tonearm setup is superior to digital music reproduction from CDs played on CD players.
In the high-fidelity debate, some prefer vacuum-tube electronics over solid-state electronics, because despite inferior measured performance, some claim a warmer or more musical sound. Vacuum-tube amplifiers are often attacked as inferior because, in addition to their substantially higher total harmonic distortion, they require rebiasing, are less reliable, generate more heat, are less powerful, and are often more expensive.
Some have long believed that sound quality was degraded by large levels of negative feedback in amplifiers. Poorly-designed feedback systems can produce poor sound quality. Thus the association of feedback with poor sound quality is likely a reflection of poorly-designed power amplifiers that use feedback incorrectly. Feedback impacts the harmonic balance of the distortion spectra.
Criticisms usually focus on claims around so-called "tweaks" and accessories beyond the core source, amplification, and speaker products. Examples of these accessories include speaker cables, component interconnects, stones, cones, CD markers, and power cables or conditioners. Manufacturers of these products often make strong claims of actual improvement in sound but do not offer any measurements or testable claims. This absence of measurable (rather than subjective) improvement, coupled with sometimes high prices, raises questions about the truthfulness of the marketing.
It is possible to spend over one hundred thousand dollars for a pair of loudspeakers, tens of thousands of dollars for electronics, and more than seven thousand dollars for cables. An example of this type of marketing, and the associated reviews in magazines, is the $1499 power cord, for which the reviewer states that "The choice of power cord one makes to transmit AC over the final feet to a component has the potential to be the most influential sonic link in a music system's power chain."
Roger Russell – a former engineer and speaker designer for McIntosh Labs – describes the introduction of expensive speaker wire brands, and critiques their performance in his online essay called Speaker Wire - A History.
Skeptic James Randi, through his foundation, has offered a prize of $1 million to anyone who can demonstrate that $7,250 audio cables "are any better than ordinary (and also overpriced) Monster Cables". To date, no one has claimed the prize.