Analysis and Detection of Imperfect Panel-form Speakers

• Main Author: 林映汝
• Other Authors: Kam, Tai-Yan
• Format: Others
• Language: zh-TW
• Published: 2012
• Online Access: http://ndltd.ncl.edu.tw/handle/32350223596198551534

碩士 === 國立交通大學 === 機械工程學系 === 101 === The purpose of the thesis is to study the behavior of imperfect panel-form speakers. A nondestructive detection device is developed for the study of speaker imperfections. The device consists of two parts, namely, upper and lower parts, which are connected by an empty box. The lower part houses the speaker for testing while the upper part a plate suspended by a surround. The speaker is excited by a harmonic load and the sound radiated from the speaker will propagate through the empty box and excite the upper plate. The response of the upper plate is measured via an accelerometer or a laser vibro-meter. Speakers with imperfections are detected from the measured frequency response functions and time response functions of the upper plate. If the measured time response function of the upper plate is not a sine wave or the frequency response function has additional frequencies except the excitation frequency, then the speaker has some kind of imperfections. The finite element software ANSYS is also used to predict the response of the upper plate to validate the suitability of the detection device. Besides, based on frequency response function, we demonstrate that the material constants can also be determined from the measured data using the proposed device.