声辐射阻抗是声优化设计中的关键设计变量,但目前尚未有成熟商用传感器面市,各种测量方法皆处于实验室研究阶段,文中研究了实验测定声辐射阻抗的基本原理,推导了用可测量——声压表达的声辐射阻抗计算公式.根据理论要求选择了实验中用以近似点声源腔的扬声器和测量结构表面及扬声器内声压的声压传感器.设计了校正腔来校准两声压传感器的相位差,选取了信号采集设备并搭建了实验系统,进行了标定实验.根据标定实验所获得的数据,通过信号后处理,得出了两声压传感器之间的相位-频率关系曲线.
The measurement principle of sound radiation resistance probe is studied in this paper. Sound radiation resistance expression is derived with measurable sound pressures. Then a small loud- speaker is selected to approximate a point simple source, two microphones are choosed to measure sur- face sound pressure and the sound pressure of loudspeaker cavity separately. A calibration chamber is designed to overcome the phase error of two microphones. A measurement system is set up. Calibra- tion experiment is carried out. By signal processing, transfer function between the microphones in the speaker and clibration cavities is got.