High fidelity

Ideally, high-fidelity equipment has inaudible noise and distortion, and a flat (neutral, uncolored) frequency response within the human hearing range.

RCA Victor began recording performances by several orchestras using optical sound around 1941, resulting in higher-fidelity masters for 78-rpm discs.

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 in 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.

Audiophiles focused on technical characteristics and bought individual components, such as separate turntables, radio tuners, preamplifiers, power amplifiers and loudspeakers.

In the late 1950s and early 1960s, the development of stereophonic equipment and recordings led to the next wave of home-audio improvement, and in common parlance stereo displaced hi-fi.

Purists generally avoid referring to these systems as high fidelity, though some are capable of very good quality sound reproduction.

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.

Many Canadian companies such as Axiom, Energy, Mirage, Paradigm, PSB, and Revel use blind testing extensively in designing their loudspeakers.

A modular system introduces the complexity of cabling multiple components and often having different remote controls for each unit.

Streaming services typically have a modified dynamic range and possibly bit rates lower than audiophile standards.