Infinite impulse response (IIR) inverse filter design for the equalization of non-minimum phase loudspeaker systems

In this paper the inverse filter design problem for non-minimum phase loudspeaker systems equalization is considered. The application of an infinite impulse response (IIR) inverse filter (pole-zero inverse system) for loudspeaker equalization is proposed. This novel solution is proposed to get lower order inverse-based equalization solutions with lower delay of the equalized system. The IIR inverse filter is designed in time domain applying a least squares criterion to the inverse pole-zero modeling "output error" configuration. The coefficients of this IIR inverse filter are obtained solving this nonlinear least squares problem by iterative optimization with an adjustable modeling delay. Loudspeaker equalization results with application of the proposed solution are presented and compared with the results of the application of a finite impulse response (FIR) filter.