Stepped sound diffuser arrangement and diffusion analysis

WANG Jundong; ZHAO Yuezhe

doi:10.16511/j.cnki.qhdxxb.2020.26.020

PDF(1226 KB)

Journal of Tsinghua University(Science and Technology) ›› 2021, Vol. 61 ›› Issue (3) : 261-268. DOI: 10.16511/j.cnki.qhdxxb.2020.26.020

ELECTRONIC ENGINEERING

Stepped sound diffuser arrangement and diffusion analysis

{{article.zuoZhe_EN}}

Author information +

History +

Abstract

Diffuser sound scattering was predicted using the finite difference time domain (FDTD) method. There were no obvious differences in the diffusion coefficient when changing the distance between the diffuser and the receivers or source in the approximate far field. Then, FDTD was combined with the immune genetic algorithm to optimize the shape of a 6th order stepped sound diffuser which had better diffusion than the original diffuser. The sound scattering from the two diffusers became less diffuse when repeated over many periods. An aperiodic modulation method was used to combine a diffuser and its inverse diffuser using a binary code. Tests show that aperiodic modulated diffusers have better diffusion than periodic diffusers; however, this modulation cannot produce a flat diffusion coefficient curve, so the best diffusion is obtained by arranging the optimized stepped diffuser with the original diffuser together using a binary code.

Key words

sound diffuser / finite difference time domain / immune genetic algorithm / diffusion coefficient / diffuser arrangement

Cite this article

EndNote

Ris (Procite)

Bibtex

Download Citations

WANG Jundong, ZHAO Yuezhe. Stepped sound diffuser arrangement and diffusion analysis[J]. Journal of Tsinghua University(Science and Technology). 2021, 61(3): 261-268 https://doi.org/10.16511/j.cnki.qhdxxb.2020.26.020

References

[1] SCHROEDER M R. Diffuse sound reflection by maximum length sequences[J]. Journal of the Acoustical Society of America, 1975, 57(1):149-150.
[2] SCHROEDER M R. Binaural dissimilarity and optimum ceilings for concert halls:More lateral sound diffusion[J]. Journal of the Acoustical Society of America, 1979, 65(4):958-963.
[3] SCHROEDER M R. Toward better acoustics for concert halls[J]. Physics Today, 1980, 33(10):24-30.
[4] COX T J. The optimization of profiled diffusers[J]. Journal of the Acoustical Society of America, 1995, 97(5):2928-2936.
[5] JRVINEN A, SAVIOJA L, MELKAS K. Numerical simulations of the modified Schroeder diffuser structure[J]. Journal of the Acoustical Society of America, 1998, 103(5):2737-2738.
[6] COX T J, AVIS M R, XIAO L. Maximum length sequence and Bessel diffusers using active technologies[J]. Journal of Sound and Vibration, 2006, 289(4-5):807-829.
[7] ZHU Y F, FAN X D, LIANG B, et al. Ultrathin acoustic metasurface-based schroeder diffuser[J]. Physical Review X, 2017, 7(2):021034.1.
[8] ANGUS J A S. Using grating modulation to achieve wideband large area diffusers[J]. Applied Acoustics, 2000, 60(2):143-165.
[9] BERKHOUT A J, PALTHE D W, DE VRIES D. Theory of optimal plane diffusers[J]. Journal of the Acoustical Society of America, 1979, 65(5):1334-1336.
[10] DE JONG D B, BERG P M. Theoretical design of optimum planar sound diffusers[J]. Journal of the Acoustical Society of America, 1980, 68(4):1154-1159.
[11] STRUBE H W. Scattering of a plane wave by a Schroeder diffusor:A mode-matching approach[J]. The Journal of the Acoustical Society of America, 1980, 67(2):453-459.
[12] STRUBE H W. More on the diffraction theory of Schroeder diffusors[J]. The Journal of the Acoustical Society of America, 1981, 70(2):633-635.
[13] COX T J, LAM Y W. The performance of realisable quadratic residue diffusers[J]. Applied Acoustics, 1994, 41(3):237-246.
[14] COX T J, LAM Y M. Prediction and evaluation of the scattering from quadratic residue diffusers[J]. Journal of the Acoustical Society of America, 1994, 95(1):297-305.
[15] SCHADY A, HEIMANN D, FENG J. Acoustic effects of trees simulated by a finite-difference time-domain model[J]. Acta Acustica United with Acustica, 2014, 100(6):1112-1119.
[16] MOKHTARI P, TAKEMOTO H, NISHIMURA R, et al. Optimum loss factor for a perfectly matched layer in finite-difference time-domain acoustic simulation[J]. IEEE Transactions on Audio, Speech and Language Processing, 2010, 18(5):1068-1071.
[17] 黄坤朋, 赵越喆. 声学FDTD法完全匹配层数和衰减系数对衰减性能的影响[J]. 华南理工大学学报(自然科学版), 2011, 39(4):135-139.HUANG K P, ZHAO Y Z. Attenuation ability influenced by amount and attenuation coefficient of perfectly matched layers in acoustic FDTD method[J]. Journal of South China University of Technology (Natural Science Edition), 2011, 39(4):135-139. (in Chinese)
[18] ISO. Acoustics-sound-scattering pro-perties of surfaces:ISO 17497[S]. Switzerland:ISO, 2012.
[19] 汪俊东, 赵越喆. 阶梯状声扩散体形体优化方法[J]. 声学学报, 2020, 45(2):281-288.WANG J D, ZHAO Y Z. Stepped soubd diffuser's shape optimization[J]. Acta Acustica, 2020, 45(2):281-288. (in Chinese)