Sound Field Radiated By A Spherical Loudspeaker Array Using A Flexible Membrane Model

Two approaches for sound field prediction of a spherical loudspeaker array operation are presented and compared to experimental measurements. In the first, real membrane modes from experimental modal analysis are used as input for BEM vibroacoustic simulations using LMS Virtual.Lab® software. In the second, an analytical solution based on the spherical harmonic expansion of an idealized velocity pattern over the spherical array is used. Results are presented in terms of sound power and directivity patterns, showing that the former has the same trend in all comparisons for the low frequency range, and that the analytical solution cannot be used for the high frequency range since it does not include the effect of the flexible membrane modes. Directivity patterns, however, show a good degree of similarity in all cases, and are not strongly affected by the flexible membrane modes.757675776Gerzon, M.A., Periphony: With-height sound reproduction (1973) Journal of the Audio Engineering Society, 21 (1), pp. 2-10Berkhout, A.J., De Vries, D., Vogel, P., Acoustic control by wave field synthesis Journal of the Acoustical Society of America, 93 (5), pp. 2764-2778Caussé, R., Bresciani, J.F., Warusfel, O., Radiation of musical instruments and control of reproduction with loudspeakers (1992) Proceedings of the International Symposium on Musical Acoustics, , Tokyo, JapanKassakian, P., Wessel, D., Characterization of spherical loudspeaker arrays (2004) Proceedings of the 117 th Audio Engineering Society Convention, , San Francisco, USA, paper number 6283Warusfel, O., Misdariis, N., Sound source radiation synthesis: From stage performance to domestic rendering (2004) Proceedings of the 116 th Audio Engineering Society Convention, , Berlin, Germany, paper number 6018Zotter, F., Sontacchi, A., Höldrich, R., Modeling a spherical loudspeaker system as multipole source (2007) Proceedings of the 33 rd German Annual Conference on Acoustics, , Stuttgart, GermanyZotter, F., (2009) Analysis and Synthesis of Sound-radiation with Spherical Arrays, , PhD dissertation, University of Music and Performing Arts, Institute of Electronic Music and Acoustics, Graz, AustriaAvizienis, R., Freed, A., Kassakian, P., Wessel, D., A compact 120 independent element spherical loudspeaker array with programmable radiation patterns (2006) Proceedings of the 120 th Audio Engineering Society Convention, , Paris, France, paper number 6783Pollow, M., Behler, G.K., Variable directivity for platonic sound sources based on spherical harmonics optimization (2009) Acta Acustica United with Acustica, 95 (6), pp. 1082-1092Pasqual, A.M., Arruda, J.R.F., Herzog, P., Application of acoustic radiation modes in the directivity control by a spherical loudspeaker array (2010) Acta Acustica United with Acustica, 96 (1), pp. 32-42Meyer, P.S., Meyer, J.D., Multi acoustic prediction program (MAPP): Recent results (2000) Tech. Rep. Presented at the Institute of Acoustics, , Meyer Sound Laboratories Inc., Stratford upon Avon, UKPasqual, A.M., (2010) Sound Directivity Control in a 3D Space by a Compact Spherical Loudspeaker Array, , PhD dissertation, State University of Campinas- Unicamp, Faculty of Mechanical Engineering, CampinasLeuridan, J., Peeters, B., Lowet, G., Van Der Auweraer, H., A new procedure for modal parameter estimation (2004) Journal of Sound and Vibration, pp. 24-28. , JanuaryVon Estorff, O., (2000) Boundary Element Acoustics- Advances & Applications, , WIT Press, Southampton (UK), 1 st Editio