Improvements in Elimination of Loudspeaker Distortion in Acoustic Measurements

This paper investigates the influence of nonlinear components that contaminate the linear response of acoustic transducers, and presents improved methods for eliminating the influence of nonlinearities in acoustic measurements. The method is evaluated with pure sinusoidal signals as well as swept sine signal and is tested on models of memoryless nonlinear systems as well as nonlinear loudspeakers. The method is shown to give a clear benefit over existing methods. Two techniques that improve the signal-to-noise ratio are demonstrated: the first uses more measurement levels than the number of orders to be separated, whereas the other one is based on standard Tikhonov regularization. Both methods are shown to significantly improve the signal-to-noise ratio.