Device and method for realizing low-frequency broadband sound absorption of small-space acoustic test box

The invention discloses a device for realizing low-frequency broadband sound absorption of a small-space acoustic test box, which comprises a box body. The inner wall of the box body is provided with a composite sound absorption layer. The device is characterized in that the composite sound absorption layer comprises a plurality of air layers for sequentially transmitting sound, the sound input side of each air layer is provided with a micro-slit plate, and a porous sound absorption material and a bottom layer sealing flat plate are arranged on the sound output side of the air layer for transmitting sound finally. By calculating the normal frequency distribution optimization size of the small-space acoustic test box, the degeneralization of the low-frequency vibration mode is avoided, and the irregular distribution condition of the frequency of the low-frequency normal vibration mode is optimized. Low-frequency acoustic dyeing and comb filtering effects in the small-space acoustic test box are reduced, and a