Harmonic balance method for estimating the nonlinear parameters of electrodynamic direct-radiator loudspeakers

Abstract

The low-frequency harmonic distortion of electrodynamic direct-radiator loudspeakers is due to the nonlinearities in the diaphragm, suspension, damping, and magnetic flux. in order to estimate such electromechanical nonlinear parameters related to harmonic distortion, a polynomial model for diaphragm displacement is adopted to describe the driving and spring forces. Each of the polynomial coefficients is evaluated by using the principle of harmonic balance. Numerical simulations are conducted for a typical loudspeaker with nonlinearities. Calculated results are in good agreement with measured diaphragm displacement curves. The present method can be used effectively as one of the methods to estimate the contribution to harmonic distortion of individual nonlinear loudspeaker parameters.