Young Brunette Girl With A Modern Hi-fi System

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.
Ascertaining high fidelity: blind tests and double-blind 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 test. This involves comparing two known audio sources (A and B) with either one of these when it has been randomly selected (X). There is no way to prove that a certain lossy methodology is transparent. To scientifically prove that a lossy method is not transparent, double-blind tests may be useful.