Glossary of Audio Terms

Electronics Industry Association. A private trade organization made up of manufacturers that set standards for voluntary use of its member companies. EIA standards for amplifier power rating require that "average power" be stated for a single channel driven driven at midband (typically 1 kHz), at a specified percentage of THD (typically 1%) to define the threshold of clipping. This easily gives numbers 10 to 20% higher than the FTC ratings. Test loads are non-inductive precision load resistors. Of the two, FTC ratings are more conservative than EIA rating. QSC publishes both FTC and EIA ratings to enable easy comparisons to other manufacturer's power ratings.

See: Equalization

To change the frequency response of a circuit, sometimes to correct for previous unequal response, and more often to cut or boost the level at certain frequencies to remove certain extraneous sounds, enhance other sounds, or completely change an existing sound to create a new sound. Much of what we refer to as "equalization" has to do with the graph of the frequency response. A flat response (with no EQ) is a straight line; a peak looks like a hill, a dip looks like a valley, and a shelf looks like a plateau. The slope is the grade of the hill.

Refers to a coloration or inaccuracy that may be sonically pleasing.