# US 12,120,495 B2 · Coaxial speaker > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 12,120,495 B2 - Document ID: US12120495B2 - Status: Granted - Kind: B2 - Application number: 18/073,524 - Filed: 2022-12-01 - Published: 2024-02-29 - Granted: 2024-10-15 - Earliest claimed: 2022-08-30 - Assignees: AAC Microtech (Changzhou) Co., Ltd. - Applicants: AAC Microtech (Changzhou) Co., Ltd. - Inventors: Zhang Ren; Zhiwei Zhong - Web page: https://patentgrep.com/patent/US12120495B2 ## CPC - H04R 9/025: {Magnetic circuit} - H04R 1/24: Structural combinations of separate transducers or of two parts of the same transducer and responsive respectively to two or more frequency ranges - H04R 7/16: Mounting or tensioning of diaphragms or cones - H04R 9/02: Details - H04R 9/06: Loudspeakers - H04R 9/063: {using a plurality of acoustic drivers (H04R1/24 and H04R1/403 take precedence)} - H04R 2400/11: Aspects regarding the frame of loudspeaker transducers - H04R 2499/11: Transducers incorporated or for use in hand-held devices, e.g. mobile phones, PDA's, camera's - H04R: LOUDSPEAKERS, MICROPHONES, GRAMOPHONE PICK-UPS OR LIKE ACOUSTIC ELECTROMECHANICAL TRANSDUCERS; ELECTRIC HEARING AIDS; PUBLIC ADDRESS SYSTEMS (producing sounds with frequency not determined by supply frequency G10K) ## Abstract The present invention provides a coaxial speaker including a frame, a magnetic circuit system, a first vibration system, and a second vibration system. The second vibration system locates coaxially with the first vibration system. The first vibration system includes a first diaphragm and a first voice coil, the second vibration system includes a second diaphragm and a second voice coil. The magnetic circuit system includes a magnetic guiding plate, a first magnet, a second magnet forming a first magnetic gap with the first magnet, a third magnet, and a forth magnet. The forth magnet, the magnetic guiding plate, and the second magnet stack in sequence and form a second magnetic gap with the third magnet. The coaxial speaker has a common magnetic circuit system for sounding on the front and back sides, which can not only form a full-range speaker, but also can function as a receiver. ## Claims ### Claim 1 A coaxial speaker, comprising: a frame; a magnetic circuit system mounted on the frame; a first vibration system fixed on a side of the frame distal to the magnetic circuit system, the first vibration system comprising a first diaphragm and a first voice coil driving the first diaphragm to generate sounds; and a second vibration system fixed on a side of the magnetic circuit system distal to the frame, the second vibration system located coaxially with the first vibration system, the second vibration system comprising a second diaphragm and a second voice coil driving the second diaphragm to generate sounds; wherein the magnetic circuit system comprises a magnetic guiding plate, a first magnet disposed on a side of the magnetic guiding plate proximal to the first diaphragm, a second magnet surrounding the first magnet and spaced apart from the first magnet to form a first magnetic gap, a third magnet surrounding the second magnet and spaced apart from the second magnet, and a forth magnet fixed on a side of the magnetic guiding plate proximal to the second diaphragm, the forth magnet, the magnetic guiding plate, and the second magnet stacked in sequence and forming a second magnetic gap with the third magnet, the first voice coil at least partially located into the first magnetic gap, the second voice coil at least partially located into the second magnetic gap. ### Claim 2 (depends on 1) The coaxial speaker as described in claim 1, wherein the first magnet, the second magnet, the third magnet, and the forth magnet are magnetized along a vibration direction of the coaxial speaker, and the first magnet, the third magnet, and the forth magnet are magnetized in same directions, and the first magnet and second magnet are magnetized in opposite directions. ### Claim 3 (depends on 2) The coaxial speaker as described in claim 2, wherein the magnetic circuit system comprises a magnetic bowl supporting the second magnet and the third magnet, a first pole plate stacked under the first magnet, and a second pole plate stacked above the third magnet, the magnetic bowl mounted on a side of the frame away from the first diaphragm. ### Claim 4 (depends on 3) The coaxial speaker as described in claim 3, wherein the coaxial speaker further comprises a first circuit board powering the first voice coil, the first circuit board comprising a first fixing portion sandwiched between the first diaphragm and the first voice coil, a second fixing portion sandwiched between the first diaphragm and the frame, an elastic first connecting portion connecting the first fixing portion and the second fixing portion, and a welding portion bending and extending from the second fixing portion to the second pole plate. ### Claim 5 (depends on 4) The coaxial speaker as described in claim 4, wherein a number of the first fixing portions is two, both sides of the first voice coil providing with one first fixing portion, and the first circuit board further comprising a second connecting portion connecting the two first fixing portions. ### Claim 6 (depends on 5) The coaxial speaker as described in claim 5, wherein the first diaphragm comprises a first dome and a first suspension surrounding the first dome, the first suspension connected to the second connecting portion of the first circuit board. ### Claim 7 (depends on 4) The coaxial speaker as described in claim 4, wherein an avoiding portion is provided on the magnetic bowl and the third magnet corresponding to a position of the welding portion for avoiding the welding portion. ### Claim 8 (depends on 2) The coaxial speaker as described in claim 2, wherein the coaxial speaker further comprises a support shelf, the second diaphragm comprising a second dome, a second suspension surrounding the second dome, a third suspension surrounding the second suspension and spaced apart from the second suspension, and a third dome located between the second suspension and the third suspension, the second dome fixed attached to the forth magnet, and the third suspension fixed attached to the support shelf. ### Claim 9 (depends on 8) The coaxial speaker as described in claim 8, wherein the second vibration system further comprises a voice coil support connecting the second diaphragm, the coaxial speaker further comprising an elastic assembly elastically suspending the second vibration system, the voice coil support comprising a flat portion attached to the third dome, a first extending portion bending and extending from one end of the flat portion to the second voice coil and connected to the second voice coil, and a second extending portion bending and extending from the other end of the flat portion to the elastic assembly and connected to the elastic assembly. ### Claim 10 (depends on 1) The coaxial speaker as described in claim 1, wherein a leakage channel is provided of the frame, the leakage channel communicating an outside world to a space enclosed by the first diaphragm and the magnetic circuit system.