Developing A Measurement System For Resonant Frequency Of Loudspeaker

The resonant frequency is an important parameter of the loudspeaker. To measure the parameter accurately and provide reliable data for speaker designers is of great importance to improve the quality of loudspeakers and enhance the competitiveness of loudspeakers’ enterprises. Aiming at the problems about high manufacturing cost of the existing loudspeaker measurement system and the longer cycle of software development, a resonant frequency measurement system of loudspeaker based on the sound card and Lab VIEW is developed.The measurement system includes two parts:hardware and software. In terms of hardware, the sound card phase22of better frequency response is selected as the data acquisition device by the frequency response test, and the selection and construction of amplifiers, mains and so on is also finished. In terms of software, graphical programming language Lab VIEW is selected as the development platform to finish the programming of the main system interface, system login, signal generation, data acquisition and processing, data encryption, database and so on.The stability error of signal is less than0.0006V by the test of system stability. By the measurement of four different types of speakers’resonant frequency and the comparison of them and the standard resonant frequency of the loudspeaker, it is founded that the measurement error of the system is less than10%.