# US 12,225,361 B2 · Sound signal processing device, sound system, and computer-implemented method > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 12,225,361 B2 - Document ID: US12225361B2 - Status: Granted - Kind: B2 - Application number: 18/158,070 - Filed: 2023-01-23 - Published: 2023-07-27 - Granted: 2025-02-11 - Earliest claimed: 2022-01-26 - Assignees: Yamaha Corporation - Applicants: Yamaha Corporation - Inventors: Toshifumi Kanno; Nobuaki Tsuji - Web page: https://patentgrep.com/patent/US12225361B2 ## CPC - H04R 3/04: for correcting frequency response - H03F 3/181: Low-frequency amplifiers, e.g. audio preamplifiers - H03F 3/189: High-frequency amplifiers, e.g. radio frequency amplifiers - H03G 11/04: Limiting level dependent on strength of signal; Limiting level dependent on strength of carrier on which signal is modulated {(H03G11/008 takes precedence)} - H03F 2200/03: the amplifier being designed for audio applications - H03F 2200/66: Clipping circuitry being present in an amplifier, i.e. the shape of the signal being modified - H04R 3/007: {Protection circuits for transducers} - H04R 2499/13: Acoustic transducers and sound field adaptation in vehicles - 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) - H03F: AMPLIFIERS - H03G: CONTROL OF AMPLIFICATION ## Abstract A sound signal processing device supplies an output sound signal to an amplification device configured to supply a first sound signal to a high-frequency speaker and a low-frequency speaker. The sound signal processing device includes a high-pass filter, an amplitude limitation circuit, a low-pass filter, and a synthesis circuit. The high-pass filter removes a low-frequency component from an input sound signal to generate a high-frequency sound signal. The amplitude limitation circuit limits an amplitude of the input sound signal at or below a reference value to generate a second sound signal. The reference value corresponds to a clipping voltage of the amplification device. The low-pass filter removes a high-frequency component from the second sound signal to generate a low-frequency sound signal. The synthesis circuit synthesizes the high-frequency sound signal and the low-frequency sound signal to generate the output sound signal. ## Claims ### Claim 1 A sound signal processing device configured to supply an output sound signal to an amplification device configured to supply a first sound signal to a high-frequency speaker and a low-frequency speaker, the sound signal processing device comprising: a high-pass filter configured to remove a low-frequency component from an input sound signal to generate a high-frequency sound signal; an amplitude limitation circuit configured to limit an amplitude of the input sound signal at or below a reference value to generate a second sound signal, the reference value corresponding to a clipping voltage of the amplification device; a low-pass filter configured to remove a high-frequency component from the second sound signal to generate a low-frequency sound signal; and a synthesis circuit configured to synthesize the high-frequency sound signal and the low-frequency sound signal to generate the output sound signal. ### Claim 2 (depends on 1) The sound signal processing device according to claim 1, wherein a cutoff frequency of the high-pass filter is equal to a cutoff frequency of the low-pass filter. ### Claim 3 (depends on 2) The sound signal processing device according to claim 2, wherein an order of the high-pass filter is equal to an order of the low-pass filter. ### Claim 4 (depends on 3) The sound signal processing device according to claim 3, wherein the reference value is determined based on the clipping voltage of the amplification device and a gain of the amplification device. ### Claim 5 (depends on 2) The sound signal processing device according to claim 2, wherein the reference value is determined based on the clipping voltage of the amplification device and a gain of the amplification device. ### Claim 6 (depends on 2) The sound signal processing device according to claim 2, further comprising an adjustment circuit configured to adjust an amplitude of a sound signal based on a volume operation performed by a user to generate the input sound signal, wherein the high-frequency speaker and the low-frequency speaker are located in a vehicle. ### Claim 7 (depends on 1) The sound signal processing device according to claim 1, wherein an order of the high-pass filter is equal to an order of the low-pass filter. ### Claim 8 (depends on 7) The sound signal processing device according to claim 7, wherein the reference value is determined based on the clipping voltage of the amplification device and a gain of the amplification device. ### Claim 9 (depends on 7) The sound signal processing device according to claim 7, further comprising an adjustment circuit configured to adjust an amplitude of a sound signal based on a volume operation performed by a user to generate the input sound signal, wherein the high-frequency speaker and the low-frequency speaker are located in a vehicle. ### Claim 10 (depends on 1) The sound signal processing device according to claim 1, wherein the reference value is determined based on the clipping voltage of the amplification device and a gain of the amplification device. ### Claim 11 (depends on 10) The sound signal processing device according to claim 10, wherein the reference value is determined based on the clipping voltage of the amplification device and a gain of the amplification device. ### Claim 12 (depends on 1) The sound signal processing device according to claim 1, further comprising an adjustment circuit configured to adjust an amplitude of a sound signal based on a volume operation performed by a user to generate the input sound signal, wherein the high-frequency speaker and the low-frequency speaker are located in a vehicle. ### Claim 13 (depends on 1) A sound system comprising: the sound signal processing device according to claim 1; the high-frequency speaker; the low-frequency speaker; and the amplification device. ### Claim 14 A sound signal processing device configured to supply an output sound signal to an amplification device configured to supply a first sound signal to a high-frequency speaker and a low-frequency speaker, the sound signal processing device comprising: a high-pass filter configured to remove a low-frequency component from an input sound signal to generate a high-frequency sound signal; a first low-pass filter configured to remove a high-frequency component from the input sound signal to generate a filter output signal; an amplitude limitation circuit configured to limit an amplitude of the filter output signal at or below a reference value to generate a second sound signal, the reference value corresponding to a clipping voltage of the amplification device; a second low-pass filter configured to remove a high-frequency component from the second sound signal to generate a low-frequency sound signal; and a synthesis circuit configured to synthesize the high-frequency sound signal and the low-frequency sound signal to generate the output sound signal. ### Claim 15 (depends on 14) The sound signal processing device according to claim 14, wherein a cutoff frequency of the high-pass filter, a cutoff frequency of the first low-pass filter, and a cutoff frequency of the second low-pass filter are equal to one another. ### Claim 16 (depends on 15) The sound signal processing device according to claim 15, wherein an order of the high-pass filter is equal to a sum of (i) an order of the first low-pass filter and (ii) an order of the second low-pass filter. ### Claim 17 (depends on 14) The sound signal processing device according to claim 14, wherein an order of the high-pass filter is equal to a sum of (i) an order of the first low-pass filter and (ii) an order of the second low-pass filter. ### Claim 18 (depends on 14) The sound signal processing device according to claim 14, wherein the reference value is determined based on the clipping voltage of the amplification device and a gain of the amplification device. ### Claim 19 A computer-implemented method of supplying an output sound signal to an amplification device configured to supply a first sound signal to a high-frequency speaker and a low-frequency speaker, the method comprising: removing a low-frequency component from an input sound signal to generate a high-frequency sound signal; limiting an amplitude of the input sound signal at or below a reference value to generate a second sound signal, the reference value corresponding to a clipping voltage of the amplification device; removing a high-frequency component from the second sound signal to generate a low-frequency sound signal; and synthesizing the high-frequency sound signal and the low-frequency sound signal to generate the output sound signal. ### Claim 20 A computer-implemented method of supplying an output sound signal to an amplification device configured to supply a first sound signal to a high-frequency speaker and a low-frequency speaker, the method comprising: removing a low-frequency component from an input sound signal to generate a high-frequency sound signal; removing a high-frequency component from the input sound signal to generate a filter output signal; limiting an amplitude of the filter output signal at or below a reference value to generate a second sound signal, the reference value corresponding to a clipping voltage of the amplification device; removing a high-frequency component from the second sound signal to generate a low-frequency sound signal; and synthesizing the high-frequency sound signal and the low-frequency sound signal to generate the output sound signal.