Identification and compensation of the electrodynamic transducer nonlinearities

Based on a simplified nonlinear lumped element model of the electrodynamic loudspeaker in either a closed or a vented cabinet, a new nonlinear controller is derived, simulated and implemented on a DSP. The Volterra series expansion, a well known functional expansion to model nonlinear systems, is used to estimate the nonlinear parameters from distortion measurements. The controller is directly based on the nonlinear differential equation, and is tested for the case of a low frequency electrodynamic loudspeaker in a closed cabinet. Digital implementation is realized on a general purpose TMS320C30 DSP development board, using the automatic code generation from schematic entry of the Alta-Group SPW software.