Patent ID: 9363604
Filing Date: 2016-06-07
CPC Classification: H04R

Claim Text:
1. A speaker box, comprising: a case having a receiving cavity; an electroacoustic transducer received in the receiving cavity and including a magnetic circuit with a magnetic gap, a diaphragm and a voice coil connected to the diaphragm, the voice coil at least partially inserted in the magnetic gap; the magnetic circuit including a first pole plate, a main magnet mounted on a central portion of the first pole plate, a ring magnet mounted on a periphery portion of the first pole plate and surrounding the main magnet forming the magnetic gap between the main magnet and the ring magnet; the first pole plate including a first main member and a plurality of first auxiliary members extending from a periphery of the first main member, and a first gap being formed between two adjacent first auxiliary members; a second pole plate concentrically attached on a lower surface of the first pole plate, the second pole plate including a second main member and a plurality of second auxiliary members extending from a periphery of the second main member, and a second gap being formed between two adjacent second auxiliary members, wherein the first main member of the first pole plate and the second main member of the second pole plate are centered together at a common center point, wherein the second gap at least partially laps over or aligns with the first gap, the second gap communicating with the first gap for communicating with external air; and the ring magnet and the first pole plate corporately forming a hole communicating the magnetic gap with the first gap of the first pole plate for leaking the air pressure of the magnetic gap.