HARMONIC-BALANCE METHOD FOR ESTIMATING THE NONLINEAR PARAMETERS OF ELECTRODYNAMIC DIRECT-RADIATOR LOUDSPEAKERS

The low-frequency harmonic distortion of electrodynamic direct-radiato r loudspeakers is due to the nonlinearities in the diaphragm, suspensi on, damping, and magnetic flux. in order to estimate such electromecha nical nonlinear parameters related to harmonic distortion, a polynomia l 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 co nducted for a typical loudspeaker with nonlinearities. Calculated resu lts are in good agreement with measured diaphragm displacement curves. The present method can be used effectively as one of the methods to e stimate the contribution to harmonic distortion of individual nonlinea r loudspeaker parameters.