A Method for Measurement and Calculation of Vertical Directivity of Line Array Loudspeaker System

Abstract

The invention discloses a measurement and reckoning method of vertical directivity of a line array speaker system. The method comprises the steps of: obtaining impulse response data of all vertical pointing angles of short line array speaker systems by measurement in an anechoic room environment, then intercepting main parts of the impulse response data, then arranging the n (n > 1 and is a positive integer) short line arrays to a long line array, carrying out shifting and linear superimposing on impulse response of the plurality of short line arrays according to time difference of radiation acoustic-waves of the short line arrays to obtain impulse response of a long line array speaker system of which length is an integral multiple thereof, and calculating vertical directivity data of allfrequency bands. According to the method of the invention, the disadvantages that measurement environments in existing measurement methods are difficult to widely recognize, and capital and time costsare high are overcome, measurement accuracy is high, efficiency is high, and a space environment of an anechoic room can be fully used.

Description

technical field [0001] The invention relates to the technical field of sound wave measurement, in particular to a method for measuring and estimating the vertical directivity of a line array loudspeaker system. Background technique [0002] In recent years, the R&D and production of line array loudspeakers have occupied a dominant position in the professional audio industry, and have been widely used in the live sound reinforcement of large venues. Vertical directivity is one of the most important aspects of the performance quality of line array loudspeakers, but there is no unified standard for its measurement. The vertical directivity of a line array loudspeaker system must be measured in the far-field region under free-field conditions. But according to the line array far-field near-field critical point formula: d=1.5*F*l 2 (where F is the frequency of the radiated sound wave, in kHz; l is the length of the short line array, in m), and the far-field distance is proporti...

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Problems solved by technology

[0006] Third, site layout, construction of measuring devices, transportation of measuring instruments, equipment, and line array speakers are costly and time-consuming

[0007] Among them, the first and second points make it difficult for the measurement environment to be widely recognized, and the third point will increase the capital and time costs of the enterprise, which is not conducive to product development and performance testing

[0008] There is also a literature report on a large-scale indoor space measurement method. For example, Engebretson et al. selected an empty hangar and placed a curved array composed of 8 loudspeakers on a flat ground to measure its directivity. This method can greatly reduce outdoor noise. The interference of meteorological conditions, but the indoor reflection cannot be ignored, and the measurement environment is also difficult to obtain wide acceptance

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