The Generating Mechanism And Analysis Method On Abnormal Response Signal For Microspeaker

Pure tone detection is an important process of quality detection of a microspeaker product, which is used to check whether the response signal is abnormal through the test of sine sweep excitation under a rated power. At present, the human ear to monitoring pure tone in electro-acoustic technology field detection is still dominant. Artificial detection method has a certain subjectivity, and it may make the auditory nerve injuried for a long time listening to loudspeaker. Along with the advancement of industrialization, the automatic detection of microspeaker’s response signal becomes an urgent problem in the electro-acoustic industry.Combining with the characteristics of the microspeaker, in this paper, the mechanism of microspeaker’s different abnormal response signal is well worth making further analysis and research. Based on the time-frequency analysis, it could use the energy statistics data of near the natural frequency region and of global high order to distinguish the speakers’ quality. In order to achieve the microspeaker’s fault sound, the sine sweep signal from the frequency sweep device incents the undetected speaker, then it transforms sound pressure signal into electrical signal via the microphone, so analog signals can transform into digital quantity signals through the data acquisition card, at the same time which completes data collection. Using short-time Fourier transform will get the digital signal’s time-frequency energy distribution, extract the above two features and mathematical statistics. According to the features of qualified speaker and fault distribution, it determines a threshold to distinguish the speakers’quality.In this paper, the main research results include:1. Giving the reason of abnormal sound fault and conducting research on the generating mechanism;2. According to the energy distribution in time-frequency diagram, it finds a way of detecting the different fault based on high-order energy around the inherent frequency area;3. Calculating the speaker’s resonance frequency based on short-time Fourier transform;4. Complete the integrated test system containing software and hardware modules.Experimental results show that the detection method that is based on high-order energy of abnormal response around the inherent frequency area can better identify the quality of microspeakers.