小功率平面揚聲器之設計與製作研究

Abstract

本文研究低功率平面揚聲器之設計與實作。設計方面，運用有限元素分析軟體ANSYS分析揚聲板的振動行為，並設計揚聲板的結構以減少中音谷的不良影響。實作方面，研究應用複合材料製作揚聲器的彈性支承，懸邊的製作與揚聲器的組裝方式等。本研究製作數種揚聲器，藉測量其實驗聲壓曲線來驗證理論聲壓分析模式的準確性，然後應用驗證後的模式研究振動板幾何比與音圈參數對聲壓曲線的影響，並找出最佳的振動板幾何比與音圈尺寸以提升聲壓曲線的平滑度與感度。最後本研究應用最佳設計結果製作揚聲器並量測其聲壓曲線，結果顯示最佳設計確實能產出聲壓較高及中音谷較小的揚聲器。

Two parts which include design and fabrication of low power flat-panel loudspeakers are studied in the thesis. The first part is about harmonic analysis and design of radiating panels using the finite element software ANSYS. The second part is about manufacture of loudspeaker components which includes suspension and elastic support, and the assembling of the loudspeakers. In fabricating the speaker, the soft suspension and elastic support are used to design the initial resonance of the speaker so that the effective frequency range can be increased and better SPL value and loudspeaker stability can be obtained in lower frequency range. Several loudspeakers are fabricated and their experimental SPL curves are used to verify the finite element model. Then based on the finite element model, the effects of aspect ratio of panel and the parameters such as voice coil diameter on the SPL curves of the loudspeakers are studied. The optimal panel aspect ratio and the diameter of voice coil for the loudspeakers are determined. It has been shown that the optimally designed loudspeaker can have smoother SPL curve and higher sensitivity.