Frequency Modulation Distortion in Loud Speakers
G. L. Beers, Herbert Belar · Journal of the Society of Motion Picture Engineers · 1943
As the frequency-response range of a sound-reproducing system is extended the necessity for minimizing all forms of distortion is correspondingly increased. The part that the loud speaker can contribute to the overall distortion of a reproducing system has been frequently considered. A type of loud speaker distortion that has not received general consideration is described. This distortion is a result of the Doppler effect and produces frequency-modulation in loud speakers reproducing complex tones. Equations for this type of distortion are given. Measurements confirming the calculated distortion in several loud speakers are shown. An appendix giving the derivation of the equations is included.