Several techniques are currently in use for measuring distortion of audio equipment. These include THD, SMPTE intermodulation, difference frequence intermodulation, and DIM (sinewave-squarewave combination). A new technique is proposed which uses a relatively large number of sinewaves to effect complex intermodulation products across the entire audio band. This paper compares the various methods, both theoretically and practically. Examples of measurements on several test circuits are presented to illustrate the results.
This paper costs $33 for non-members and is free for AES members and E-Library subscribers.