On Rayleigh distance and absorption length of parametric loudspeakers

This paper investigates the propagation of primary and secondary waves produced by parametric loudspeakers of different sizes. The theory of the parametric acoustic array describes the nonlinear interaction of waves to be confined to the near-field, but the nonlinearities may remain over the far-field, producing different results. Four simulations were done to compare the performance of loudspeakers with different Rayleigh distances. Based on the simulations, a new design was proposed to overcome the mismatching of absorption length and Rayleigh distance. Control over these distances is proposed as an improvement of the performance of the parametric loudspeaker, considering the required scope and proper application.