# US 12,192,698 B2 · Loudspeaker with reduced audio coloration caused by reflections from a surface > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 12,192,698 B2 - Document ID: US12192698B2 - Status: Granted - Kind: B2 - Application number: 18/377,261 - Filed: 2023-10-05 - Published: 2024-02-08 - Granted: 2025-01-07 - Earliest claimed: 2014-09-30 - Assignees: Apple Inc. - Applicants: Apple Inc. - Inventors: Martin E. Johnson; Simon K. Porter; Suzanne Hardy; John H. Sheerin - Web page: https://patentgrep.com/patent/US12192698B2 ## CPC - H04R 1/2811: {for loudspeaker transducers} - H04R 1/02: Casings; Cabinets {; Supports therefor;} Mountings therein (H04R1/28 takes precedence {; attachments for microphones H04R1/08; mounting of transducers in earpieces H04R1/1075}) - H04R 1/025: {Arrangements for fixing loudspeaker transducers, e.g. in a box, furniture} - H04R 1/26: Spatial arrangements of separate transducers responsive to two or more frequency ranges - H04R 1/2803: {for loudspeaker transducers} - H04R 1/288: {for loudspeaker transducers} - H04R 1/403: {loud-speakers} - H04R 3/14: Cross-over networks - H04R 2201/401: 2D or 3D arrays of 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 Loudspeakers are described that may reduce comb filtering effects perceived by a listener by either 1) moving transducers closer to a sound reflective surface (e.g., a baseplate, a tabletop or a floor) through vertical (height) or rotational adjustments of the transducers or 2) guiding sound produced by the transducers to be released into the listening area proximate to the reflective surface through the use of horns and openings that are at a prescribed distance from the reflective surface. The reduction of this distance between the reflective surface and the point at which sound emitted by the transducers is released into the listening area may lead to shorter reflected path that reduces comb filtering effects caused by reflected sounds that are delayed relative to the direct sound. Accordingly, the loudspeakers shown and described may be placed on reflective surfaces without severe audio coloration caused by reflected sounds. ## Claims ### Claim 1 An electronic device comprising: a housing; an audio receiver disposed within the housing and configured to wirelessly receive a digital audio signal from an external device and generate transducer drive signals; a plurality of power amplifiers disposed within the housing and coupled to receive the transducer drive signals from the audio receiver and generate amplified transducer drive signals; a plurality of audio transducers disposed within the housing, wherein each audio transducer in the plurality of audio transducers is coupled to receive an amplified transducer drive signal output from one of the plurality of power amplifiers and wherein the plurality of audio transducers include a plurality of tweeters oriented such that a forward face of each diaphragm of the plurality of tweeters is oriented downward; and one or more acoustic channels defined by horns that redirect sounds generated by the plurality of tweeters to one or more sound output openings of the device housing. ### Claim 2 (depends on 1) The electronic device set forth in claim 1, wherein the transducer drive signals generated by audio receiver are digital transducer drive signals and the electronic device further includes circuitry coupled between the audio receiver and the power amplifiers to convert the digital transducer drive signals to analog transducer drive signals that are received by the plurality of power amplifiers. ### Claim 3 (depends on 1) The electronic device set forth in claim 1, wherein the audio receiver includes both wireless and wired inputs. ### Claim 4 (depends on 1) The electronic device set forth in claim 1, wherein the audio receiver is configured to wirelessly receive the digital audio signal using a Bluetooth protocol. ### Claim 5 (depends on 1) The electronic device set forth in claim 1, wherein the audio receiver is configured to wirelessly receive the digital audio signal using a wireless protocol in accordance with an 802.11 suite of standards. ### Claim 6 (depends on 1) The electronic device set forth in claim 1, wherein the plurality of tweeters are evenly spaced about the housing and aligned in a first horizontal plane. ### Claim 7 (depends on 6) The electronic device set forth in claim 6 wherein the plurality of audio transducers further includes a low frequency transducer configured for low frequency content and wherein the plurality of tweeters are configured for content within a frequency range higher than the low frequency transducer. ### Claim 8 (depends on 1) The electronic device set forth in claim 1, wherein each transducer in the plurality of audio transducers is independently and separately driven to generate sound patterns that represent individual channels of sound content received at an audio input. ### Claim 9 (depends on 8) The electronic device set forth in claim 8, wherein the sound patterns differ in shape and direction. ### Claim 10 (depends on 1) The electronic device set forth in claim 1, wherein the housing is axisymmetric. ### Claim 11 (depends on 1) The electronic device set forth in claim 1 further comprising: one or more processing components; and a memory unit coupled to and readable by the one or more processing components and storing therein a set of instructions which, when executed by the one or more processing components, cause the processing components to implement an operating system for the electronic device and generate transducer drive signals from the digital audio signals. ### Claim 12 (depends on 11) The electronic device set forth in claim 11, wherein the memory unit comprises a non-volatile random access memory. ### Claim 13 (depends on 11) The electronic device set forth in claim 11, wherein the one or more processing components is further configured to decode digital audio stored locally on the electronic device. ### Claim 14 (depends on 11) The electronic device set forth in claim 11, wherein the plurality of tweeters are aligned in a first horizontal plane and wherein the plurality of transducers includes at least one second transducer aligned in a second horizontal plane spaced apart vertically from the first horizontal plane. ### Claim 15 (depends on 14) The electronic device set forth in claim 14, wherein the second transducer is a low frequency transducer configured for low frequency content and wherein each transducer in the plurality of tweeters is configured for content within a frequency range higher than the low frequency transducer. ### Claim 16 (depends on 1) The electronic device set forth in claim 1, further comprising digital-to-analog converter circuitry coupled to inputs of the plurality of power amplifiers and configured to convert digital transducer drive signals received at the digital-to-analog converter circuitry to analog transducer drive signals transmitted to the plurality of power amplifiers. ### Claim 17 (depends on 11) The electronic device set forth in claim 11, further comprising a second audio input configured to receive analog audio signals from an external device. ### Claim 18 (depends on 11) The electronic device set forth in claim 11, wherein the housing is axisymmetric. ### Claim 19 (depends on 11) The electronic device set forth in claim 11, wherein the housing is cylindrical.