Journal Article
Charge Movements on the Stretched Membrane in a Circular Electrostatic Push-Pull Loudspeaker
Journal of the Audio Engineering Society · Volume 38 · Issue 5 · pp. 331–339 · May 1990
Abstract
An analysis is made of the charge movements on the membrane of an electrostatic push-pull loudspeaker. It is shown that in steady-state operation (harmonic exitation) the movement of charge causes two important effects: harmonic distortion and a net change of static membrane charge. The former effect is found to be of minor interest in properly designed loudspeakers, whereas the latter causes the steady-state frequency characteristics to be input-level dependent. Measurements show that this level dependence may reach values well above 1-dB deviation from strictly linear behavior. A theoretical model is presented from which the charge distribution in a circular electrostatic push-pull loudspeaker can be calculated. The theoretical results are shown to conform with measurements.
