# US 12,225,364 B2 · Speaker device and control method thereof > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 12,225,364 B2 - Document ID: US12225364B2 - Status: Granted - Kind: B2 - Application number: 17/952,321 - Filed: 2022-09-26 - Published: 2023-06-29 - Granted: 2025-02-11 - Earliest claimed: 2021-12-28 - Assignees: Roland Corporation - Applicants: Roland Corporation - Inventors: Naoshi Miyoshi; Masato Ueno - Web page: https://patentgrep.com/patent/US12225364B2 ## CPC - H04R 5/04: Circuit arrangements, {e.g. for selective connection of amplifier inputs/outputs to loudspeakers, for loudspeaker detection, or for adaptation of settings to personal preferences or hearing impairments (combinations of amplifiers H03F3/68; stereophonic systems H04S)} - G10H 3/186: {Means for processing the signal picked up from the strings (filtering G10H1/12)} - H03F 3/181: Low-frequency amplifiers, e.g. audio preamplifiers - 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 5/02: Spatial or constructional arrangements of loudspeakers - H04S 1/007: {in which the audio signals are in digital form (data reduction aspects thereof based on psychoacoustics G10L19/02)} - H04S 7/307: {Frequency adjustment, e.g. tone control (H04S7/301 takes precedence)} - H03F 2200/03: the amplifier being designed for audio applications - 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) - G10H: ELECTROPHONIC MUSICAL INSTRUMENTS; INSTRUMENTS IN WHICH THE TONES ARE GENERATED BY ELECTROMECHANICAL MEANS OR ELECTRONIC GENERATORS, OR IN WHICH THE TONES ARE SYNTHESISED FROM A DATA STORE - H03F: AMPLIFIERS - H04S: STEREOPHONIC SYSTEMS ## Abstract A speaker device includes left and right speakers and a correction part. The correction part corrects frequency characteristics of a stereo audio signal supplied to the left and right speakers so that transfer characteristics of the left and right speakers become predetermined transfer characteristics. ## Claims ### Claim 1 A speaker device comprising: left and right speakers; and a correction part which corrects frequency characteristics of a stereo audio signal to be supplied to the left and right speakers so that transfer characteristics of the left and right speakers become predetermined transfer characteristics, wherein the correction part corrects the stereo audio signal so that the transfer characteristics of the left and right speakers are flattened across all audio signal frequencies. ### Claim 2 (depends on 1) The speaker device according to claim 1, wherein the correction part corrects the stereo audio signal so that the transfer characteristics of the left and right speakers are different from transfer characteristics of the left and right speakers of a case in which a monaural audio signal is supplied to the left and right speakers. ### Claim 3 (depends on 1) The speaker device according to claim 1, wherein the correction part corrects the stereo audio signal so that the transfer characteristics of the left and right speakers become transfer characteristics of speakers of a type different from the left and right speakers. ### Claim 4 (depends on 1) The speaker device according to claim 1, further comprising: an expansion effect imparting part which imparts a sound image expansion effect to a stereo audio signal before being corrected by the correction part, so that a range of a localizable sound image is expanded beyond an interval between the left and right speakers. ### Claim 5 (depends on 1) The speaker device according to claim 1, further comprising: an expansion effect imparting part which imparts a sound image expansion effect to a stereo audio signal having been corrected by the correction part, so that a range of a localizable sound image is expanded beyond an interval between the left and right speakers. ### Claim 6 (depends on 1) The speaker device according to claim 1, further comprising: an expansion effect imparting part which imparts a sound image expansion effect to a second stereo audio signal to be synthesized with a first stereo audio signal which is the stereo audio signal, so that a range of a localizable sound image is expanded beyond an interval between the left and right speakers. ### Claim 7 (depends on 1) The speaker device according to claim 1, further comprising: an expansion effect imparting part which imparts a sound image expansion effect to an audio signal obtained by synthesizing a first stereo audio signal which is the stereo audio signal and a second stereo audio signal which is different from the first stereo audio signal, so that a range of a localizable sound image is expanded beyond an interval between the left and right speakers. ### Claim 8 (depends on 1) The speaker device according to claim 1, further comprising: a sound effect imparting part which imparts a sound effect to a monaural audio signal in a monaural mode in which a monaural audio signal is supplied to the left and right speakers. ### Claim 9 (depends on 8) The speaker device according to claim 8, wherein the sound effect imparting part comprises at least one of a first sound effect imparting part which imparts a sound effect to an inputted monaural audio signal, and a second sound effect imparting part which imparts a stereo sound effect to the inputted monaural audio signal. ### Claim 10 (depends on 8) The speaker device according to claim 8, wherein the sound effect imparting part is turned off in a case where the monaural mode transitions to a stereo mode in which a stereo audio signal is supplied to the left and right speakers. ### Claim 11 A control method of a speaker device, comprising: correcting, by a speaker device comprising left and right speakers, frequency characteristics of an inputted stereo audio signal so that transfer characteristics of the left and right speakers become predetermined transfer characteristics, wherein the transfer characteristics of the left and right speakers are flattened across all audio signal frequencies; and supplying, by the speaker device, a corrected stereo audio signal to the left and right speakers. ### Claim 12 A speaker device, operable in a monaural mode in which a monaural audio signal is supplied to a plurality of speakers and a stereo mode in which a stereo audio signal is supplied to the plurality of speakers, the speaker device comprising: a correction part which corrects frequency characteristics of the stereo audio signal so that transfer characteristics of the plurality of speakers in the stereo mode are different from transfer characteristics of the plurality of speakers in the monaural mode, wherein the correction part corrects the stereo audio signal so that the transfer characteristics of the left and right speakers are flattened across all audio signal frequencies. ### Claim 13 (depends on 12) The speaker device according to claim 12, further comprising: an expansion effect imparting part which imparts a sound image expansion effect to a stereo audio signal before being corrected by the correction part, so that a range of a localizable sound image is expanded beyond an interval between the plurality of speakers. ### Claim 14 (depends on 12) The speaker device according to claim 12, further comprising: an expansion effect imparting part which imparts a sound image expansion effect to a stereo audio signal having been corrected by the correction part, so that a range of a localizable sound image is expanded beyond an interval between the plurality of speakers. ### Claim 15 (depends on 12) The speaker device according to claim 12, further comprising: an expansion effect imparting part which imparts a sound image expansion effect to a second stereo audio signal to be synthesized with a first stereo audio signal which is the stereo audio signal, so that a range of a localizable sound image is expanded beyond an interval between the plurality of speakers. ### Claim 16 (depends on 12) The speaker device according to claim 12, further comprising: an expansion effect imparting part which imparts a sound image expansion effect to an audio signal obtained by synthesizing a first stereo audio signal which is the stereo audio signal and a second stereo audio signal which is different from the first stereo audio signal, so that a range of a localizable sound image is expanded beyond an interval between the plurality of speakers.