QRD位置对房间声场均匀度的影响研究

Research on the influence of QRD position on room sound field uniformity

QRD(Quadratic Remainder Diffuser)作为调控房间声场均匀度的常见材料,其在房间中的分布位置影响房间声场均匀度的调控效果.研究了QRD在房间中不同的位置分布对房间声场均匀度的影响.通过混响室实验测试的方法,改变QRD在混响室中的分布位置,测试了六种布置方案,研究频域、时域分析QRD位置的改变对不同测点间声压级关系的影响.结果发现:频域内,Sp(声压级平方的标准差)比SL(声压级的标准差)描述声场均匀度更加合适,尤其适用于低频声场;随着频率的升高,SL对声场均匀度的描述准确度提高;时域内,当房间内QRD的面积一定时,其均匀分布于房间的天花板或者侧墙时,声场内各点的声压级标准差较小,声场均匀度较好;为发挥QRD低频吸声的优势,应将其布置于房间低频模式声压值极大位置,即降低由于共振频率引起房间声场不均匀的影响程度.

QRD(Quadratic Remainder Diffuser)is a common material to control the sound field uniformity which of the distribution affects the uniformity of sound field in the room.This article describes the influence of QRD’s different position distribution on the room’s sound field uniformity through the method of experimental testing in the reverberation room.In the frequency and time domain,there are six layout schemes of the different distribution of QRD in the reverberation room,analyzing the influence of the change of QRD position through the sound pressure level relationship between different measuring points.In the frequency domain,the results show that Sp(standard deviation of the square of sound pressure level)is more suitable than SL(standard deviation of sound pressure level)to describe the uniformity of the sound field,especially suitable for low-frequency sound fields.With the increase of frequency,the accuracy of SL’s description of sound field uniformity is improved.In the time domain,when the QRDs are evenly distributed on the ceiling or side wall with the constant area in the room,the standard deviation of sound pressure level at each point in the sound field is smaller and the sound field uniformity is better.To take the advantage of low-frequency sound absorption of QRD,it should be arranged at the position where the sound pressure value is maximum in the low-frequency mode of the room,which can reduce the influence degree of uneven sound field in the room caused by resonance frequency.