Velocity controlled sound field reproduction by non-uniformly spaced loudspeakers

Abstract

One approach to the reproduction of a sound field is to ensure the reproduction of the acoustic pressure on the surface bounding the volume within which reproduction is sought.However, this approach suffers from technical limitations when the loudspeakers used for the reproduction of the surface acoustic pressures are unevenly spaced. It is shown in this paper that sound field reproduction with a spatially non-uniform loudspeaker arrangement can be considerably improved by changing the physical quantity to be controlled on the bounding surface from pressure to particle velocity. One of the main advantages of the velocity control method is the simplicity with which the inverse problem can be regularized, irrespective of the direction of arrival of the sound to be reproduced. In addition, the velocity controlled sound field shows better reproduction of the time averaged intensity flow in the reproduction region which in turn appears to be closely linked with better human perception of sound localization. Furthermore, the proposed method results in smoother "panning functions" that describe the variation of the source outputs as a function of the angle of incidence of the sound to be reproduced. The performance of the velocity matching method has been evaluated by comparison to the conventional pressure matching method and through simulations with several non-uniform loudspeaker layouts. The simulated results were also verified with experiments and subjective tests.

Optimization of Architectural Electroacoustics Design for the Interior Mezzanines of Vertical Buildings

“…When loudspeakers, as electronic devices, are distributed evenly and sufficiently, the particular reproduction of the pressure field on the bounding surface of the control volume clearly provides an effective method of reproduction. Most of similar findings have analyzed many hybrid factors technically (Poletti, 2011;Shin et al, 2016;Zhao et al, 2017) or for small or non-vertical spaces (Spaeth, 2015;Iswati, 2016;Lu et al, 2016;Shih et al, 2016;). However, there were no specific results of them related to the requirements for architectural acoustics, especially for vertical mezzanines.…”

3D sound field reproduction in arbitrary listening zone for multichannel system

“…Sound pressure [5] and particle velocity [6] at the receiving point produced by a point source locating at are, respectively, …”

“…Pressure matching in a same zone method (PMSZ) [4,5] and particle velocity matching in a same zone method (PVMSZ) [6] matches sound pressure or particle velocity in a same zone between original system and reproduced system respectively. Though tests are only made in central zone sound field reproduction in [4][5][6], PMSZ and PVMSZ could be used for non-central zone sound field reproduction from their theories.…”

“…Pressure matching in a same zone method (PMSZ) [4,5] and particle velocity matching in a same zone method (PVMSZ) [6] matches sound pressure or particle velocity in a same zone between original system and reproduced system respectively. Though tests are only made in central zone sound field reproduction in [4][5][6], PMSZ and PVMSZ could be used for non-central zone sound field reproduction from their theories. But PMSZ and PVMSZ have following theoretical defects: (1) in non-central zone sound field reproduction, the best case is that a noncentral zone of original sound field is recovered, whose listening experience is worse than the listening experience in the central zone of original system; (2) sound pressure and particle velocity are two main factors to describe sound [7], but PMSZ and PVMSZ just maintain one of them.…”

“…Definition: Sound pressure [5] p(r, j) and particle velocity [6] u(r, j) at the receiving point r = (r x , r y , r z ) produced by a point source locating at…”