Mechanical resonances and geometrical nonlinearities in electrodynamic loudspeakers
Abstract
For high amplitudes of vibration loudspeakers are subject to nonlinear phenomena that are responsible for audible distortions such as intermodulation or harmonic distortion. The lowfrequency model uses nonlinear lumped parameters and is only valid around the first mechanical resonance since it assumes a rigid body movement. In the present study a model of the electromechanical problem including the effects of diaphragm modal resonances using the state-space formalism is proposed. No approximation of the nonlinear behavior of the electrical parameters is necessary for the direct calculation of the vibration pattern. The model is developed for one degree of freedom (plane piston approximation) and then expanded to an n-degree-of-freedom system. allowing one to model mechanical resonances and geometrical nonlinearities of the system.