AES New York 2013
Product Design Track Event PD2
Friday, October 18, 5:30 pm — 7:00 pm (Room 1E07)
Product Design: PD2 - High-Order Harmonic Distortion Measurement of Amplifiers and its Impact on FidelityPresenters:
Dan Foley, Audio Precision - Worcester, MA, USA
Roger Gibboni, Rogers High Fidelity - Warwick, NY, USA
The electronics side of the audio industry has standardized on THD and THD+N as the main means of characterizing distortion, especially for amplifiers. However in 1942, RCA engineers who wrote the Radiotron Handbook proposed a weighted THD metric that weighted the energy of high-order harmonics to a much greater degree than low-order harmonics. Listening tests back then did show a correlation of amplifiers with very little high-order harmonic distortion being more acceptable compared to other designs with greater high-order distortion even though THD differed slightly. This presentation will focus on current measurement methods that can be used to separate high-order and low-order distortion.