A measure of all the harmonic distortion components (i.e.,second harmonic, third harmonic,etc.) produced by an audio device, expressed as a percentage of the fundamental signal. Called "total" because it is the sum of all the individual harmonic-distortion components created by the component.
A number representing the total amount of distortion or misrepresentation of a sound passing through an amplifier or speaker; how much unwanted coloration the system adds to the original sound.
(THD) - the percentage, in relation to a pure input signal, of harmonically derived frequencies introduced in the sound reproducing circuitry and hi-fi equipment (including speakers).