墙截面优化声学小房间低频响应的鲁棒性分析

Robustness analysis for low frequency response in a room with optimized walls

改进了通过优化墙截面形状改善声学小房间低频响应的优化方法,实现了墙面阶梯形状宽度和深度同时优化。在60- 120 Hz频段对优化后房间频响随声源位置的鲁棒性进行了分析,并与未优化的房间比较。结果表明:对一个5×4．65×2．68 m3的小房间优化后,210个不同位置点声源所激励房间声场的频响标准偏差(SRD)平均值从未优化房间的9．66 dB下降为6．17 dB,频响最大偏离值(MD)平均值从未优化房间的41．27 dB下降为17．42 dB;SRD和MD值的标准差分别比未优化房间下降了44．8％和63．9％。证明了墙截面优化不仅能够使房间频响变好,而且小房间内频响对于声源位置的敏感程度也随着墙截面形状的优化而降低。通过运用优化的墙截面改善房间低频响应鲁棒性是有意义的。

The method of using optimized wall section had been improved . Widths and depths of wells in wall were optimized synchronously to improve low frequency response in a room. By calculating frequency response from 60 Hz to 120 Hz, when source located at different locations in a room, robustness of an optimized room had been analyzed and compared with the results in an original room. The results showed that after optimization design, average of the squared root deviation of sound frequency response （SRD） reduced from 9.66 dB in a 5 × 4.65 × 2.68 m^3 room to 6.17 dB; average of the maximum deviation of sound frequency response （MD） reduced from 41.27 dB to 17.42 dB; standard deviation of SRD reduced 44.8% and standard deviation of MD reduced 63.9%. These results demonstrated that optimized wall not only had effect on improving frequency response, but also had effect on reducing frequency response sensitivity to sound source location. Therefore, it was useful to use optimized wall section to improve robustness of low frequency response.