US 12,238,474 B2
Speaker box
Yao Hui, Shenzhen (CN); Yufen Chu, Shenzhen (CN); Jiujian Liu, Shenzhen (CN); and Weimin Chen, Shenzhen (CN)
Assigned to AAC Technologies Pte. Ltd., Singapore (SG)
Filed by AAC Technologies Pte. Ltd., Singapore (SG)
Filed on Dec. 28, 2022, as Appl. No. 18/089,575.
Application 18/089,575 is a continuation of application No. PCT/CN2022/120175, filed on Sep. 21, 2022.
Claims priority of application No. 202210975595.7 (CN), filed on Aug. 15, 2022.
Prior Publication US 2024/0056728 A1, Feb. 15, 2024
Int. Cl. H04R 7/18 (2006.01); H04R 1/02 (2006.01); H04R 1/28 (2006.01); H04R 7/04 (2006.01); H04R 9/02 (2006.01); H04R 9/04 (2006.01); H04R 9/06 (2006.01)
CPC H04R 1/2826 (2013.01) [H04R 1/025 (2013.01); H04R 7/04 (2013.01); H04R 7/18 (2013.01); H04R 9/025 (2013.01); H04R 9/045 (2013.01); H04R 9/063 (2013.01); H04R 2400/11 (2013.01)] 10 Claims
OG exemplary drawing
 
1. A speaker box, comprising a housing and a sound unit fixedly accommodated in the housing, wherein the sound unit comprises a bracket, a vibration system and a magnetic circuit system having a magnetic gap, the vibration system and the magnetic circuit system are fixed to the bracket, the magnetic circuit system comprises a yoke, a primary magnet fixed to the yoke and a secondary magnet spaced from the primary magnet to form the magnetic gap, wherein
the housing comprises a bottom cover fixed to the bracket, the bottom cover, the bracket and the magnetic circuit system form a rear cavity, the bottom cover comprises one or more leakage holes provided through the bottom cover, and the rear cavity is in communication with outside through the one or more leakage holes; and
the speaker box further comprises a magnetic circuit coupling valve accommodated in the rear cavity, the magnetic circuit coupling valve comprises a support fixed to the bracket or the yoke, a negative stiffness diaphragm fixed to the support and a coil fixed on a side of the negative stiffness diaphragm close to the secondary magnet and separated from the secondary magnet, the negative stiffness diaphragm faces to and is separated from the one or more leakage holes, and the coil receives an external control signal and generates an electromagnetic field with the secondary magnet to drive the negative stiffness diaphragm to abut on and seal the one or more leakage holes to a closed state, or drive the negative stiffness diaphragm to separate from the one or more leakage holes to make the one or more leakage holes open, or drive the negative stiffness diaphragm to partially abut on the one or more leakage holes to make the one or more leakage holes partially open or closed.