振膜与音圈粘结间隙对高频截止的影响*

利用声学理论及Comsol仿真对电动式高音扬声器声压级高频进行分析，重点研究了高音振膜与音圈的粘结状态对声压级高频截止的影响。根据实例分析，当音圈与振膜之间的粘结间隙被中心胶填充时，Klippel测试的声压级高频提前截止。通过对中心胶粘结位置相关的类比线路图分析可知，扬声器高频截止频率主要受振膜和中心胶的刚性影响，当中心胶粘结位置存在间隙时，因中心胶材料与骨架材料比模量的差异，Cglue变大，此时整体刚性变小，会使振动能量由音圈骨架传递到振膜材料时的传递速率受到削减，表现为高频截止频率降低。Comsol仿真分析表明，音圈骨架与振膜粘结位置存在间隙时，高频振动模态发生弯曲，影响振动能量的传递，高频提前截止，与实例分析的结果一致。

Analysis on the influence of the gap between diaphragm and voice coil on high frequency cutoff

The high frequency of sound pressure level (SPL) of electric tweeter was analyzed based on acoustic theory. The influence of the bonding state between the tweeter diaphragm and the voice coil on the high frequency cutoff of SPL was studied. The example analysis showed when there was a large gap between the voice coil and the diaphragm filled by the center glue, the Klippel tested SPL high frequency cutoff. According to the electromechanical and acoustic analysis of the position of the center glue, the cutoff frequency of the loudspeaker was mainly affected by the rigidity of the diaphragm and the center glue. When there was a gap in the central glue bonding position, due to the difference in the specific modulus between the central glue and the bobbin material, the Cglue became larger, and the overall rigidity became smaller. As a result, the transfer rate of vibration energy from the voice coil bobbin to the diaphragm material would be reduced, high frequency cutoff frequency was reduced. The simulation analysis of Comsol showed that when there was a gap between the bond position of voice coil bobbin and diaphragm, the high frequency vibration mode would be bent, which affected the transmission of vibration energy, and the high frequency was cut off in advance, which was consistent with the results of example analysis.