The Disegn And Optimization Of High-power Loudspeaker Based On The Compression Driver

Horn loaded compression driver’s appearance improves the low efficiency and directivity of traditional transducer. With the development of phase plug theory and horn theory, high-power acoustic directional loudspeaker based on horn loaded compression driver has become the main trend of modern directional acoustic weapons. Using horn loaded compression driver with high sound pressure level(SPL) and high efficiency and transducer array, it can emit sound waves with high directivity to control and attack the specific object. However, research on effects of the phase plug and horn on transducer’s conversion efficiency, acoustic field distribution, beam width and SPL is an open area.The thesis focuses on the theoretical analysis and optimal design of the horn-loaded compression driver’s phase plug and horn. First, the principle of the compression driver and phase horn’s structural property are demonstrated. The driver’s lumped parameter model is established to determine the maximum power point and discuss the effect of the main parameters on its performance. Meanwhile, the requirements on the design of driver are proposed according to the technical specifications of high-power acoustic directional loudspeaker.Second, the acoustic characteristics for the driver with or without phase plus are analyzed. The function of the phase plus is mainly pinpointed. Using Smith theory and Bessel equations in cylindrical coordinates constructed by using modal suppression method, the position and entrance area for the phase plug having three annular passageways are designed. Also, numerical simulation is conducted to verify that such phase plus can be effectively control the acoustic resonance.Lastly, the characteristics of 60??40? horn, including far-field radiation, impedance and sound-field distribution, are numerically analyzed under the modal excitation via boundary element method and mode decomposition theory. The disadvantage of the horn on the far-field directivity is identified. Then, horn with identical beam width is realized through the least square method. In terms of the directivity of the horn-loaded compression driver, numerical simulation and experimental measurement are performed. It is concluded that such design satisfies the performance requirement of the high-power acoustic directional loudspeaker.