# US 11,310,587 B2 · Horn loudspeakers > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 11,310,587 B2 - Document ID: US11310587B2 - Status: Granted - Kind: B2 - Application number: 16/595,723 - Filed: 2019-10-08 - Published: 2021-04-08 - Granted: 2022-04-19 - Earliest claimed: 2019-10-08 - Assignees: Bose Corporation - Applicants: Bose Corporation - Inventors: David Edwards Blore; Randy J. Kulchy; Robert Preston Parker - Web page: https://patentgrep.com/patent/US11310587B2 ## CPC - H04R 1/2865: {for loudspeaker transducers} - H04R 1/30: Combinations of transducers with horns, e.g. with mechanical matching means {, i.e. front-loaded horns}(horns in general G10K; {transducer enclosures or mountings using a back-loaded horn H04R1/2861; application of horns as guiding means to obtain a predetermined directivity characteristic H04R1/345}) - H04R 1/2849: {for loudspeaker transducers} - H04R 1/2873: {for loudspeaker transducers} - H04R 1/288: {for loudspeaker transducers} - 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 A loudspeaker includes a first electro-acoustic transducer, a horn acoustically coupled to the first electro-acoustic transducer, and a first acoustic leak that is acoustically coupled to the horn. The first acoustic leak is positioned so as to reduce a peak in a frequency response of the loudspeaker at the targeted frequency without removing the targeted frequency from the output of the loudspeaker. ## Claims ### Claim 1 A loudspeaker comprising: a first electro-acoustic transducer; a horn acoustically coupled to the first electro-acoustic transducer; and a first acoustic leak acoustically coupled to the horn, wherein the first acoustic leak is positioned so as to reduce a peak in a frequency response of the loudspeaker at a targeted frequency without removing the targeted frequency from the output of the loudspeaker, and wherein the first acoustic leak comprises a stub that defines an acoustic channel that has a length that is ¼ the wavelength (λ) of the target frequency, the ¼ λ stub further being in the form of a tube that circumferentially surrounds the horn. ### Claim 2 (depends on 1) The loudspeaker of claim 1, wherein the first acoustic leak comprises an acoustic resistive element. ### Claim 3 (depends on 2) The loudspeaker of claim 2, wherein the first acoustic leak further comprises a sealed back enclosure disposed along an outer surface of the horn. ### Claim 4 (depends on 1) The loudspeaker of claim 1, wherein the first acoustic leak further comprises an acoustically absorbent material disposed within the acoustic channel, wherein the acoustically absorbent material broadens out the affected frequency bandwidth, effectively lowering the quality factor, Q, of the first acoustic leak. ### Claim 5 (depends on 4) The loudspeaker of claim 4, wherein the acoustically absorbent material comprises a cotton batting, a synthetic fiber batting, or an acoustically absorbent foam. ### Claim 6 (depends on 1) The loudspeaker of claim 1, wherein the ¼λ stub includes an open end that is acoustically coupled to the horn via one or more apertures, a closed end, opposite the open end, and a body that extends substantially parallel to the outer surface of the horn between the open and closed ends. ### Claim 7 (depends on 1) The loudspeaker of claim 1, wherein the ¼λ stub comprises an acoustically absorbent material disposed within the acoustic channel, wherein the acoustically absorbent material broadens out the affected frequency bandwidth, effectively lowering the quality factor, Q, of the first acoustic leak. ### Claim 8 (depends on 7) The loudspeaker of claim 7, wherein the acoustically absorbent material comprises a cotton batting, a synthetic fiber batting, or an acoustically absorbent foam. ### Claim 9 (depends on 1) The loudspeaker of claim 1, wherein the first acoustic leak comprises a Helmholtz absorber comprising: an enclosed volume; a port having a first end that is acoustically coupled to the horn and a second end, opposite the first end, that is acoustically coupled to the enclosed volume; and an acoustically absorbent material disposed within the Helmholtz absorber. ### Claim 10 (depends on 9) The loudspeaker of claim 9, wherein the acoustically absorbent material comprises a cotton batting, a synthetic fiber batting, or an acoustically absorbent foam. ### Claim 11 (depends on 1) The loudspeaker of claim 1, further comprising a second acoustic leak, wherein the first acoustic leak and the second acoustic leak are configured for reducing different, respective peaks in the output of the loudspeaker. ### Claim 12 (depends on 11) The loudspeaker of claim 11, wherein the horn includes a first horn section and a second horn section, wherein the first acoustic leak is configured to reduce a first peak in the output of the loudspeaker corresponding to a first resonance in the first horn section and the second acoustic leak is configured to reduce a second peak in the output of the loudspeaker corresponding to a second resonance in the second horn section. ### Claim 13 (depends on 12) The loudspeaker of claim 12, wherein the first and second acoustic leaks are arranged in the first horn section. ### Claim 14 (depends on 1) The loudspeaker of claim 1, wherein the horn includes a first horn section and a second horn section. ### Claim 15 (depends on 14) The loudspeaker of claim 14, wherein the first acoustic leak is disposed in first horn section. ### Claim 16 (depends on 14) The loudspeaker of claim 14, wherein the first acoustic leak is arranged such that it is closer to an interface of first and second horn sections than it is to the first electro-acoustic driver. ### Claim 17 (depends on 2) The loudspeaker of claim 2, wherein the acoustic resistive element comprises a metallic screen. ### Claim 18 (depends on 1) The loudspeaker of claim 1, further comprising an acoustic enclosure, and a second electro-acoustic transducer, wherein the first electro-acoustic transducer, the horn, and the second electro-acoustic transducer are supported in the acoustic enclosure. ### Claim 19 (depends on 18) The loudspeaker of claim 18, wherein the first electro-acoustic transducer is a high-frequency driver and second electro-acoustic transducer is a low-frequency driver.