This paper seeks a solution to optimize the length of the acoustic channels in a large dome diaphragm compression drivers phasing plug, thereby forming the output wavefront and controlling directivity at high frequencies. Normally, the channels of such a driver are designed to have equal impedances. This implies equal lengths and a similar expansion ratio. This results in the assumption that the wave front should be flat at the output of the phasing plug. However, the horn cannot control the directivity of the driver at high frequencies, and it is controlled by the size of the drivers exit. To find a solution to this problem, a study on the impact of the shape of the wavefront on the directivity was performed. A convex spherical wavefront with different radii was analyzed, and directivity was modeled using the finite element analysis. The results presented in this work show that the shape of the wavefront at the exit of the compression driver can have a significant impact on the directivity at high frequencies. This solution enables the design of a large-format compression driver providing directivity control at high frequencies using a phasing plug with optimized channel lengths. An exponential horn and a constant directivity horn were used in experiments.
(See document for exact affiliation information.)
Click to purchase paper as a non-member or login as an AES member. If your company or school subscribes to the E-Library then switch to the institutional version. If you are not an AES member Join the AES. If you need to check your member status, login to the Member Portal.
