Semi-anechoic box for wide frequency bandwidth measurement

Abstract

A semi-anechoic box for wide frequency bandwidth measurement comprises a barrel-shaped box body, a measurement microphone is arranged at the center of the box body, sound absorption materials or sound absorption structures are arranged on the inner walls of all faces, except the face where an object to be measured is installed, of the box body, the space standoff distances between the microphone and the surfaces of the sound absorption materials or the sound absorption structures are more than 20 cm, the space standoff distances are related to the minimum measuring frequency for measuring, and the lower the minimum measuring frequency is, the larger the space standoff distances are. The cross section of the interior of the barrel-shaped box body is polygonal, and the cross section of an outer box body is rectangular. According to the barrel-shaped box body, space occupied by sound insulation and absorption materials is small, no special large-size test chamber is needed, use convenience is achieved, large-scale product quality detection is facilitated, and production test cost is lowered; the sound insulation and absorption materials are firmly installed, and test operations are easy and convenient; because the sound insulation property is good, a measuring device is less disturbed by the outside, and accordingly test precision is high, test data repeatability is good and the semi-anechoic box can be used in different environments.

Description

1. Technical field [0001] The invention relates to a semi-anechoic box for broadband measurement, or an anechoic device which approximates the measurement effect of a semi-anechoic chamber. 2. Background technology [0002] The acoustic performance of loudspeakers, mobile phones and other sound-generating devices, such as frequency response, total harmonic distortion, etc., is required to be measured under free field (anechoic chamber) or semi-free field (semi-anechoic chamber) conditions. However, the volume of the anechoic chamber or the semi-anechoic chamber is large and the cost is high, especially inconvenient to operate on the production line. Therefore, a semi-anechoic box for wide-band measurement that can simulate the measurement effect of an anechoic room or a semi-anechoic room has become the best choice in the industry. Effect. [0003] Existing technology simulates the measurement of anechoic chamber or semi-anechoic chamber, especially for the acoustic perfor...

AI Technical Summary

Problems solved by technology

However, the sound absorption effect of sound-absorbing cloth wrapped with sound-absorbing cotton is far from being comparable to that of the anechoic room.

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