Influence of low-order room reflections on sound zone system performance

Abstract

Studies on sound field control methods able to create independent listening zones in a single acoustic space have recently been undertaken due to the potential of such methods for various practical applications, such as individual audio streams in home entertainment. Existing solutions to the problem have shown to be effective in creating high and low sound energy regions under anechoic conditions. Although some case studies in a reflective environment can also be found, the capabilities of sound zoning methods in rooms have not been fully explored. In this paper, the influence of low-order (early) reflections on the performance of key sound zone techniques is examined. Analytic considerations for small-scale systems reveal strong dependence of performance on parameters such as source positioning with respect to zone locations and room surfaces, as well as the parameters of the receiver configuration. These dependencies are further investigated through numerical simulation to determine system configurations which maximize the performance in terms of acoustic contrast and array control effort. The design rules for source and receiver positioning are suggested, for improved performance under a given set of constraints such as a number of available sources, zone locations and the direction of the dominant reflection.

Generation of Private Sound With a Circular Loudspeaker Array and the Weighted Pressure Matching Method

“…Previous works have investigated the design of systems for sound field control in reverberant environments [38], [39] and the negative effects of reverberation on system performance [40], [43], [47]. A number of strategies have been devised to mitigate such negative effects by means, for example, of higher order sources [41], [42] or by exploiting first order reflections [45], [46], [41], [44].…”

Optimal source placement for sound zone reproduction with first order reflections

“…The nulls can be steered by adjusting source weights and positions with respect to the dark zone and surfaces 22 . This can be complementary to using directive sources.…”

The Design of Personal Audio Systems for Speech Transmission Using Analytical and Measured Responses

“…Implementations and analyses of sound zoning systems have been conducted in anechoic environments e.g. [8,9,10], with the inclusion of reflections from the head [11], individual room reflections [12] and general reverberation e.g. [3,13,14,15].…”