THEORETICAL AND EXPERIMENTAL COMPARISON OF 3 METHODS FOR COMPENSATIONOF ELECTRODYNAMIC TRANSDUCER NONLINEARITY

Based on a simplified nonlinear lumped-element model of an electrodyna mic loudspeaker, nonlinear compensators are derived, simulated, and im plemented on a digital signal processor (DSP). The model comprises thr ee major nonlinearities: voice-coil excursion dependent force factor, (suspension) stiffness, and self-inductance. A Volterra series expansi on is used to estimate nonlinear parameters from distortion measuremen ts. The first compensation method utilizes the second-order s-domain k ernel of this expansion to synthesize a second-order compensator. The other two methods employ extended mirror filter and state-space techni ques, respectively. All three approaches an compared with respect to n eeded dynamic elements, computational complexity, robustness, and effe ctiveness for the case of a low-frequency direct radiator in a closed cabinet.