平板扬声器立体声重放的振动对比度控制方法*

利用激振器阵列通过振动对比度控制方法实现了在平板扬声器上重放立体声的声源局域化控制。首先利用激振器到测量点的导纳函数,最大化辐射区和整个平板振动区域的平均动能比值得到阵列的最优空间滤波器。然后分别计算最大化左右声道辐射区和整个振动区域平均动能比值的最优滤波器。最后将立体声信号分别通过对应辐射区最优滤波器滤波相加后,馈给激振器阵列激励平板在两辐射区辐射对应声道的信号。利用8个激振器控制0.48 m长、0.27 m宽、0.001 m厚铝板,在100 Hz～2000 Hz范围内,振动对比度的均值为12 dB。因此该方法可以获得较好的局域化控制效果,进而可以将左右声道的声源局域在平板扬声器的两侧。

Vibrational contrast control for stereo audio reproduction on flat panel loudspeaker

A vibrational contrast control method is proposed for stereo audio reproduction on a thin plate, which is based on maximizing the contrast of the average energy of transverse motion between the radiated zone and the entire vibration zone. Firstly, the optimal filter group for the actuator array is obtained by using the mobility functions from the actuators to the measurement points. Secondly, the optimal filter groups for the left channel signals and the right channel signals are obtained to maximize the average kinetic energy of the left radiated zone and the right radiated zone respectively. Finally, the stereo audio signals are played by the corresponding radiated zone. Experimental results on an 0.480m by 0.270m by 0.001m thick aluminum panel with 8 actuators show that the contrast level is about 12dB for the frequency band from 100Hz to 2000Hz. Therefore, high contrast level can be achieved and the stereo audio can be played on a single flat panel loudspeaker.