Conference Paper

Soundfield rendering with loudspeaker arrays through multiple beam shaping

Dipt. di Elettron. ed Inf., Politec. di Milano, Milan, Italy
DOI: 10.1109/ASPAA.2009.5346484 Conference: Applications of Signal Processing to Audio and Acoustics, 2009. WASPAA '09. IEEE Workshop on
Source: DBLP

ABSTRACT

This paper proposes a method for the acoustic rendering of a virtual environment based on a geometric decomposition of the wavefield into multiple elementary acoustic beams, all reconstructed with a loudspeaker array. The point of origin, the orientation and the aperture of each beam is computed according to the geometry of the virtual environment that we want to render and to the location of the sources. Space-time filters are computed with a Least Squares approach to render the desired beam. Experimental results show the feasibility as well as the critical issues of the proposed algorithm.

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Available from: Fabio Antonacci
    • "Solutions based on spatial distributions of loudspeakers constitute today a wellestablished technology, aimed at eliciting in the listener a deep sense of immersion [1]. In broad terms, what such solutions do is to reproduce a desired sound field through the superposition of the contributions of secondary sources, whose driving signals can be obtained analytically [2] [3] [4] [5] [6] [7] [8] or as a numerical approximation of the solution of an inverse problem [9] [10] [11] [12] [13]. "
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    ABSTRACT: In this manuscript we propose an analytic solution to the problem of sound field rendering, based on the plane wave decomposition, which is here derived with reference to the Herglotz density function. The plane wave decomposition encodes the directional contributions to the sound field, and allows us to describe elementary sound fields in a model-based fashion, parameterized only by the source location. We show how this representation can be exploited for rendering purposes using a wide variety of loudspeaker arrangements. We start by deriving closed-form expressions for the loudspeaker weights based on the plane wave decomposition and we validate this derivation with an analysis of the reproduction error for the case of a circular array of speakers. We then show how to extend the proposed method to non-circular geometries. We assess the performance of the proposed rendering solution for various array configurations, offering a comparison with state-of-the-art analytical rendering techniques.
    No preview · Article · Mar 2016 · Applied Acoustics
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    • "In the last decades, controllable directivity patterns were adopted for sound reinforcement applications [1]. Recently, thanks to the availability of fast beam tracing techniques [2] [3], controlled directivity patterns have been used for immersive sound reinforcement in reverberant environments [4] and for sound field rendering [5] [6]. Many beamforming design techniques have been proposed for the purpose of spatially selective sound capture and, thanks to the reciprocity between microphones and loudspeakers [7], these techniques can be readily applied to the sound playback scenario [8] [9]. "
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    ABSTRACT: In this paper we propose a robust beamforming technique which takes into account uncertainties and variations in the radiation pattern of the loudspeakers. The proposed technique is based on the solution of a robust least-square problem in which the propagation matrix is to some extent unknown. Both simulations and experimental results prove the validity of the proposed methodology in terms of directivity index and white noise gain.
    Full-text · Conference Paper · May 2014
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    • "where˜G (x u |x m , ω) is the Green's function at x u , given the loudspeaker position x m . Similarly, we compute the sound fields˜p G (x u , ω) and˜p W (x u , ω) of GR and WFS, respectively , where the rendering filters are obtained through a duly implementation of the methdologies proposed in [4] and [9]. Simulated sound fields allow us to qualitatively compare the accuracy of rendering for different techniques. "
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    ABSTRACT: In this paper we present a technique for the rendering of directional sources by means of loudspeaker arrays. The proposed methodology is based on a decomposition of the sound field in terms of plane waves. Within this framework the directivity of the source is naturally included in the rendering problem, therefore accommodating the directivity into the picture becomes much simpler. For this purpose, the loudspeaker array is subdivided into overlapping sub-arrays, each generating a plane wave component. The individual plane waves are then weighed by the desired directivity pattern. Simulations and experimental results show that the proposed technique is able to reproduce the sound field of directional sources with an improved accuracy with respect to existing techniques.
    Full-text · Conference Paper · Sep 2013
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