薄板扬声器的声辐射特性研究

Study on the Sound Radiation Characteristics of Panel Loudspeaker

引入扬声系统的音质评价标准,研究薄板扬声器相对于动圈式扬声器声辐射特性的优劣.建立了四边简支矩形薄板在单点激励下受迫振动的力学模型,根据有限元理论,利用Matlab将薄板划分为318个三角形单元模拟薄板的弯曲振动,利用Matlab对可听声频段内的50个点的声压级进行数值计算,得到频率响应特性,薄板扬声器的频率响应曲线比动圈扬声器平直,没有明显的辐射指向性,非线性失真和瞬态失真小,可实现双向同相位辐射,音质特性优于动圈扬声器.

To study the sound radiation characteristic excellence of panel loudspeaker compared to moving-coil loudspeakers, timbre appraising standard was introduced. A mechanical model was set up where the four sides simply supported rectangle panel vibrates under a single point exciter. The panel was plotted out as 318 triangular elements using the Matlab according to finite element procedures. Flexural vibration of panel was simulated. SPL of 50 points in the range of audible frequency was calculated using the Matlab. Frequency response characteristics were established. The frequency response curve of the panel loudspeaker is found to be more even than the curve of moving-coil loudspeaker. There is no obviously directional characteristics. Nonlinear distortion and transient distortion are rather small. The panel loudspeaker can achieve bipolar radiation. The timbre characteristics of the panel loudspeaker are better than the moving-coil loudspeaker.