Abstract
A reflection-resistive sound reconstruction system is proposed for audio reproduction with extended sweet spot and reduced boundary reflections. The method adopts a combined approach of equivalent source method (ESM)-based sound field synthesis (SFs) and acoustic contrast control (ACC). The conventional SFS that is based on the free-field assumptions suffer from synthesis error due to boundary reflections. To overcome the problem, the proposed system utilizes convex optimization in designing array filters to tradeoff reproduction performance and acoustic contrast. Upmixing and interpolation strategies are also proposed for the improvement of internal reproduction performance. Cost functions and constraints are defined, in conjunction with 1, 2 and infinity norms. Control points are deployed in the dark zone to minimize the sound field in the exterior region. Two approaches are employed to constrain the pressure and both pressure and velocity in the dark zone. Guidelines for choosing optimization parameter are summarized. Two performance measures, pressure matching error (PME) and acoustic contrast (AC), are adopted in simulations and experiments using a rectangular loudspeaker array. Perceptual Evaluation of Audio Quality (PEAQ) is also used in the objective of reproduction quality. The results show that the interpolation is available method for performance enhancement. The pressure-constrained (PC) method yields better acoustic contrast, but poorer reproduction performance than the pressure-velocity constrained (PVC) method. Two indices, acoustic contrast and reproduction performance, of a specific system are in tradeoff. Furthermore, the PVC method is the suitable method used for constrained method due to its better performance in auditory perception. High acoustic contrast can be achieved by deploying a large number of control points in the dark zone or choosing 1-norm as the conjunction in the cost function.