ABSTRACT
Headphones normally replay stereo sound tracks created using loudspeakers in recording control rooms. The wide availability of sound mixing and processing programs, and the low cost of powerful computers, has given almost anybody access to capabilities that once were the exclusive domain of elaborate recording studio facilities. Sound reproducing systems and devices are highly variable in sound quality, and misguided room equalization practices contribute to that variability. Singers had to be careful not to be louder than the machine, to learn to imitate the sound of the machine, and to sing without vibrato. Audiophiles seeking excellence in sound reproduction are frequently advised by journalists and reviewers who have little or no awareness of the research that has been done. Looking at the music side of sound reproduction, the circle of confusion can be reduced to the elements. The few standards that have been written for broadcast, control and music listening rooms employed questionable measurements and criteria.
