设计制作了外形为椭球形的小型扬声器系统(声源)。该声源的等效直径约0.047m,当声源距离不小于1.0m时能满足较高的声源空间分辨率;频率响应范围为400Hz~20kHz;额定功率下1.0m处的辐射声压级达到76dB;在声源辐射正向±30。的区域内基本满足无指向性,且其指向特性与刚球表面局部圆形脉动声源模型的理论计算值基本吻合。因此。该扬声器系统的各项参数和技术指标均适合于高空间分辨率头相关传输函数的测量。
In this paper, an elliptical micro-loudspeaker system (sound source) is designed and manufactured. The equivalent diameter of sound source is about 0.047 m, which guarantees the spatial high-resolution of sound source when the sound source distance is not less than 1.0 m. The frequency response of sound source within the range of 400 Hz to 20 kHz is good. Under the rated power, the radiation sound pressure level (SPL) of sound source reaches to 75 dB at 1.0 m. The directivity of sound source is approximately consistent with that of local circle pulsating sound source on a rigid sphere, and the non--directivity can be realized in the ±30° region near the positive direction of radiation field. As a result, the sound source with the parameters mentioned above is suitable for (and has been used to) the measurements of spatial high-resolution head-related transfer functions.