Modeling and Experimental Study of Loudspeaker Directivity Patterns in the Far and Near Fields

The current paper reviews theoretically and examines experimentally the polar plot of a loudspeaker in the far and near field. An original equation for sound pressure calculation in the near and far field is proposed. An experiment is conducted to confirm the theoretical data and the accuracy of the proposed expression. Several conclusions are drawn from the analysis of the study. Sound emission from a linear array of loudspeakers, whose excitation factors are set in accordance with the Bessel functions, creates a sound pressure distribution in the plane of the loudspeaker axes that corresponds to the radiation pattern of a single loudspeaker. Experimental data confirms that the Bessel array's directivity pattern broadens compared to a linear array of loudspeakers with a constant excitation factor, and approaches that of a single loudspeaker. Considering the analyzed patterns in selecting the number of loudspeakers is recommended when designing Bessel arrays to create an omnidirectional sound pressure distribution with an overall increase in sound pressure level. The novelty and originality of this work lies in its ability to more accurately determine the fundamental resonance frequency of a loudspeaker's moving system, establish the optimal amplifier output stage load and crossover filter element data, and also improve the frequency range, rated power, and sensitivity.