# US 12,003,945 B2 · Audio reproduction device > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 12,003,945 B2 - Document ID: US12003945B2 - Status: Granted - Kind: B2 - Application number: 17/415,981 - Filed: 2019-10-09 - Published: 2021-12-09 - Granted: 2024-06-04 - Earliest claimed: 2018-12-28 - Assignees: Sony Group Corporation - Applicants: Sony Group Corporation - Inventors: Shinsaku Saijo - Web page: https://patentgrep.com/patent/US12003945B2 ## CPC - H04S 7/30: {Control circuits for electronic adaptation of the sound field} - H04S 7/302: {Electronic adaptation of stereophonic sound system to listener position or orientation (H04S7/301 takes precedence)} - H03F 3/20: Power amplifiers, e.g. Class B amplifiers, Class C amplifiers (H03F3/26 - H03F3/30 take precedence) - H03F 3/68: Combinations of amplifiers, e.g. multi-channel amplifiers for stereophonics {(power amplifiers using a combination of several semiconductor amplifiers H03F3/211; combinations of amplifiers using coupling networks with distributed constants H03F3/602)} - H04R 3/00: Circuits for transducers (arrangements for producing a reverberation or echo sound G10K15/08; amplifiers H03F) - H04R 3/12: for distributing signals to two or more loudspeakers {(specially adapted for hearing aids H04R25/407)} - H04R 2430/01: Aspects of volume control, not necessarily automatic, in sound systems - H04S 2400/01: Multi-channel, i.e. more than two input channels, sound reproduction with two speakers wherein the multi-channel information is substantially preserved - H04S 2400/13: Aspects of volume control, not necessarily automatic, in stereophonic sound systems - H04S: STEREOPHONIC SYSTEMS - H03F: AMPLIFIERS - 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 To provide an audio reproduction device including: a signal processing circuit that generates multi-channel audio data; an attenuation amount control unit that is connected to the signal processing circuit and controls an attenuation amount of audio data of each channel; and a speaker device that is driven by a multi-channel audio signal from the attenuation amount control unit and has multi-channel speakers including a woofer, in which the attenuation amount control unit estimates, from an audio data value of each channel, a total value of currents flowing through the speaker device, and controls the attenuation amount in such a way that the estimated total value of currents does not exceed a predetermined value that has been set in advance, and the attenuation amount is controlled in accordance with a priority that has been set in advance in such a way that relationships between the channels are maintained. ## Claims ### Claim 1 An audio reproduction device, comprising: a signal processing circuit configured to generate multi-channel audio data; an attenuation amount control unit that is connected to the signal processing circuit, wherein the attenuation amount control unit is configured to control an attenuation amount of audio data of each channel; and a speaker device that is driven by a multi-channel audio signal from the attenuation amount control unit, wherein the speaker device includes multi-channel speakers, the multi-channel speakers includes a woofer, the attenuation amount control unit is further configured to: estimate, from an audio data value of each channel, a total value of currents that flows through the speaker device, and control the attenuation amount of the audio data of each channel in such a way that the estimated total value of currents does not exceed a specific value, and the attenuation amount of the audio data of each channel is controlled based on a ranking associated with each of the multi-channel speakers. ### Claim 2 (depends on 1) The audio reproduction device according to claim 1, wherein the attenuation amount control unit is further configured to control each sample of the audio data of each channel. ### Claim 3 (depends on 1) The audio reproduction device according to claim 1, wherein the multi-channel speakers includes the woofer and a plurality of speakers excluding the woofer, attenuation of the audio data for the woofer is ranked first, attenuation of the audio data for the plurality of speakers excluding the woofer is ranked second, an attenuation amount of the audio data for the woofer is set to change the audio data for the woofer to zero at a maximum, and attenuation amounts of the audio data for the plurality of speakers is set to values within a specific range, and are substantially equal among the plurality of speakers. ### Claim 4 (depends on 1) The audio reproduction device according to claim 1, wherein the multi-channel speakers include the woofer and a plurality of speakers excluding the woofer, the plurality of speakers includes a first group and a second group, attenuation of the audio data for the woofer is ranked first, attenuation of the audio data for the first group is ranked second, and attenuation of the audio data for the second group is ranked third, an attenuation amount of the audio data for the woofer is set to change the audio data for the woofer to zero at a maximum, attenuation amounts of the audio data for the first group are set to values within a first range, and are substantially equal among the plurality of speakers of the first group, and attenuation amounts of the audio data for the second group are set to values within a second range, and are substantially equal among the plurality of speakers of the second group. ### Claim 5 (depends on 4) The audio reproduction device according to claim 4, wherein a maximum value within the second range is smaller than a maximum value within the first range. ### Claim 6 (depends on 4) The audio reproduction device according to claim 4, wherein the first group contributes less to sound image localization in space than the second group. ### Claim 7 (depends on 4) The audio reproduction device according to claim 4, wherein the first group includes speakers positioned substantially in center when viewed from a listener side, and the second group includes speakers at left and right when viewed from the listener side. ### Claim 8 An audio reproduction device, comprising: a signal processing circuit configured to generate multi-channel audio data; an attenuation amount control unit that is connected to the signal processing circuit, wherein the attenuation amount control unit is configured to control an attenuation amount of audio data of each channel; and a speaker device that is driven by a multi-channel audio signal from the attenuation amount control unit, wherein the speaker device includes multi-channel speakers, the multi-channel speakers includes a woofer, the attenuation amount control unit is further configured to: estimate, from an audio data value of each channel, a total value of currents that flows through the speaker device, control attenuation amount of the audio data of each channel in such a way that the estimated total value of currents does not exceed a specific value allowed by a power supply, perform a first determination processing operation for determination of whether the total value of currents exceeds the specific value in a case where the audio input-data for the woofer is attenuated up to zero, cause the audio data for the woofer to be attenuated by a required amount in a case where it is determined that the total value of currents does not exceed the specific value, and perform, in a case where it is determined in the first determination processing operation that the total value of currents exceeds the specific value, a second determination processing operation for determination of whether the total value of currents exceeds the specific value in a case where the audio data for the woofer is attenuated to substantially zero, and then the audio data for a plurality of speakers excluding the woofer is attenuated in a range of up to a value, and cause the audio data for the plurality of speakers excluding the woofer to be attenuated by a required amount in a case where it is determined that the total value of currents does not exceed the specific value. ### Claim 9 (depends on 8) The audio reproduction device according to claim 8, wherein the plurality of speakers excluding the woofer includes a first group and a second group, the second determination processing operation is performed on the first group, and in a case where it is determined in the second determination processing operation that the total value of currents exceeds the specific value, the audio data for speakers of the first group is attenuated to a maximum value within a first range, and then the audio data for speakers of the second group is attenuated in a second range of up to a value.