A study of different tapering windowing functions and referencing curve for the improvement of sound field using wave-field synthesis

Abstract

Wavefield synthesis is a well-known sound field reproduction technique. The correct synthesis of the desired sound field ideally requires a continuous source distribution over an enclosed surface. Due to practical limitations, a finite length of secondary source array is used. This results in distortion in the reproduced sound field due to the diffraction effect from the edge loudspeakers. To alleviate this problem, tapering window functions are utilized. In this paper, the influence of various windowing functions on the reproduced fields for different secondary source geometry and virtual source type is studied, and different parameters are used to make a quantitative comparison between the performance of different windowing functions. Further, the effect of the different referencing curves for the synthesis of correct amplitude is also presented. From the simulation results, it was found that the Tukey window function provides a wider sweet spot area with a minimal amplitude ringing effect. The selection of a proper referencing curve depends on the array geometry and the type of virtual source.