Adaptive Linearization of A Loudspeaker

II. THE ADAPTIVE PRE-DISTORTION SCHEME This paper presents a new and promising application for adaptive nonlinear filters adaptive linearization of a loudspeaker. In a loudspeaker, the nonlinearity in the suspension system produces a significant distortion at low frequencies and the inhomogeneity in the flux density causes a nonlinear distortion at large output signals. These distortions should be reduced so that high fidelity sound can be reproduced. The conventional feedback technique has difficulties combating the nonlinear distortions due to an air path delay in the feedback signal. An adaptive approach may lead to a good solution. An adaptive pm-distortion linearization scheme, together with other schemes, was recently presented in [1] for a weakly nonlinear system. This paper employs the pre-distortion scheme for linearizing a loudspeaker. A model of a direct radiator loudspeaker has been developed and studied which takes into account the two principal sources of nonlinear distortions Based on this model, simulations of the proposed method have been performed. The results have shown that nonlinear distortions of a loudspeaker can be reduced significantly.