# US 11,451,917 B2 · Acoustic system with spatial effect > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 11,451,917 B2 - Document ID: US11451917B2 - Status: Granted - Kind: B2 - Application number: 17/283,349 - Filed: 2019-10-09 - Published: 2022-01-06 - Granted: 2022-09-20 - Earliest claimed: 2018-10-09 - Assignees: Devialet - Applicants: Devialet - Inventors: Antoine Petroff - Web page: https://patentgrep.com/patent/US11451917B2 ## CPC - H04R 3/12: for distributing signals to two or more loudspeakers {(specially adapted for hearing aids H04R25/407)} - H04S 3/00: Systems employing more than two channels, e.g. quadraphonic (H04S5/00, H04S7/00 take precedence) - H04R 1/403: {loud-speakers} - H04S 1/002: {Non-adaptive circuits, e.g. manually adjustable or static, for enhancing the sound image or the spatial distribution (control circuits for electronic adaptation of the sound field H04S7/30)} - H04S 3/002: {Non-adaptive circuits, e.g. manually adjustable or static, for enhancing the sound image or the spatial distribution (control circuits for electronic adaptation of the sound field H04S7/30)} - H04R 2201/401: 2D or 3D arrays of transducers - 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 2400/03: Aspects of down-mixing multi-channel audio to configurations with lower numbers of playback channels, e.g. 7.1 -> 5.1 (H04S2400/01 takes precedence) - H04S 2400/07: Generation or adaptation of the Low Frequency Effect [LFE] channel, e.g. distribution or signal processing - 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) - H04S: STEREOPHONIC SYSTEMS ## Abstract An acoustic system (1) for diffusing sound from N channels (Si) comprising audio frequencies, N being greater than or equal to two, the acoustic system comprising a frame (5), M loudspeakers (HPj) which are similar to each other and mounted on the frame (5), and a processing unit (20) designed to send M loudspeaker signals (SSj) to the loudspeakers respectively. The loudspeakers are arranged at an angle about an axis (Z), two successive loudspeakers forming an angle (a) substantially equal to 360° divided by M. The processing unit (20) comprises a splitter (28) configured to produce the loudspeaker signals (SSj), each loudspeaker signal comprising the same shared bass component (SSLF) in which audio frequencies that are higher than a first predetermined frequency (f1) are non-existent or reduced, at least two of the loudspeaker signals further comprising a specific component (SSj,MF) in addition to the shared bass component and in which the audio frequencies below the first frequency are non-existent or reduced, each specific component being obtained from at least one of the channels, and at least two of the specific components being different from each other. ## Claims ### Claim 1 An acoustic system designed for diffusing sound from N channels comprising audio frequencies, N being greater than or equal to two, the acoustic system comprising: a frame, M loudspeakers structurally similar to each other and mounted on the frame, M being greater than or equal to two, and a processing unit designed for sending M loudspeaker signals to the respective loudspeakers, wherein: the loudspeakers are arranged at an angle about an axis intended to be substantially vertical, two successive loudspeakers forming an angle substantially equal to 360° divided by M, and the processing unit comprises a splitter configured to produce the loudspeaker signals, each loudspeaker signal comprising a same shared bass component obtained from at least one of the channels, and in which the audio frequencies that are higher than a predetermined first frequency are non-existent or reduced, at least two of the loudspeaker signals further comprising a specific component in addition to the shared bass component and in which the audio frequencies below the first frequency are non-existent or reduced, each specific component being obtained from at least one of the channels, and at least two of the specific components being different from each other, wherein the acoustic system further comprises a frequency selector adapted to produce, from each channel, on the one hand a low frequency signal in which the audio frequencies of the channel higher than the first frequency are non-existent or reduced, and on the other hand, if said channel comprises audio frequencies that are higher than the first frequency, at least one other signal in which the audio frequencies of the channel lower than the first frequency are non-existent or reduced, the shared bass component being proportional to the sum of the low frequency signals, the specific components being obtained from the other signals, and wherein the frequency selector is further configured to extract, from each respective channel comprising audio frequencies that are higher than a predetermined second frequency, a high-frequency signal in which the audio frequencies of said channel lower than the second frequency are non-existent or reduced, the second frequency being higher than the first frequency, the frequency selector being configured so that, in each of the other signals, the audio frequencies that are higher than the second frequency are non-existent or reduced; and at least one of the loudspeaker signals formed by the splitter further comprises a shared high frequency component proportional to the sum of the high frequency signals, the shared high frequency component being added to the shared bass component. ### Claim 2 (depends on 1) The acoustic system according to claim 1, wherein the first frequency is greater than or equal to 200 Hz and less than or equal to 500 Hz. ### Claim 3 (depends on 1) The acoustic system according to claim 1, wherein the specific components are linear combinations of at least some of the other signals. ### Claim 4 (depends on 1) The acoustic system according to claim 1, wherein the second frequency is greater than or equal to 1000 Hz and less than or equal to 10000 Hz. ### Claim 5 (depends on 1) The acoustic system according to claim 1, wherein: the acoustic system is designed for diffusing the sound from a stereo source, the channels comprising a left channel L and a right channel R; the number M of loudspeakers is equal to two, the loudspeakers comprising a first loudspeaker HP1 receiving a first loudspeaker signal SS1; and a second loudspeaker HP2 receiving a second loudspeaker signal SS2; and the splitter is configured so that: SS1=a*[1*LMF+SSLF+SSHF] and SS2=a*[1*RMF+SSLF+SSHF], with SSLF=½*(LLF+RLF) and SSHF=½*(LHF+RHF), LLF being the low frequency signal of the left channel L, LMF being the other signal of the left channel L, LHF being the high frequency signal of the left channel L, RLF being the low frequency signal of the right channel R, RMF being the other signal of the right channel R, RHF being the high frequency signal of the right channel R, a being a proportionality coefficient. ### Claim 6 (depends on 1) The acoustic system according to claim 1, wherein: the acoustic system is designed for diffusing the sound from a stereo source, the channels comprising a left channel L and a right channel R; the number M of loudspeakers is equal to three, the loudspeakers comprising a first loudspeaker HP1 receiving a first loudspeaker signal SS1, a second loudspeaker HP2 receiving a second loudspeaker signal SS2, and a third loudspeaker HP3 receiving a third loudspeaker signal SS3; and the splitter is configured so that: SS1=a*[½*(LMF+RMF)+SSLF+SSHF], SS2=a*[½*LMF+SSLF+SSHF], and SS3=a*[½*RMF+SSLF+SSHF], with SSLF=⅓*(LLF+RLF) and SSHF=⅓*(LHF+RHF), LLF being the low frequency signal of the left channel L, LMF being the other signal of the left channel L, LHF being the high frequency signal of the left channel L, RLF being the low frequency signal of the right channel R, RMF being the other signal of the right channel R, RHF being the high frequency signal of the right channel R, a being a proportionality coefficient. ### Claim 7 (depends on 1) The acoustic system according to claim 1, wherein: the acoustic system is designed for diffusing the sound from a source with five channels S1 to S5 and one channel S6 with no audio frequencies that are higher than the first frequency; the number M of loudspeakers is three, the loudspeakers including a first loudspeaker HP1 receiving a first loudspeaker signal SS1, a second loudspeaker HP2 receiving a second loudspeaker signal SS2, and a third loudspeaker HP3 receiving a third loudspeaker signal SS3; and the splitter is configured so that: SS1=a*[⅓*S1,MF+⅓*S2,MF+1*S3,MF+SSLF+SSHF], SS2=a*[⅔*S1,MF+1*S4,MF+SSLF+SSHF], and SS3=a*[⅔*S2,MF+1*S5,MF+SSLF+SSHF], with SSLF=⅓*(S1,LF+S2,LF+S3,LF+S4,LF+S5,LF+S5,LF+S6,LF), and SSHF=⅓*(S1,HF+S2,HF+S3,HF+S4,HF+S5,HF+S5,LF), S1,LF to S6,LF being the low frequency signals of channels S1 to S6, with S6,LF=S6, S1,MF to S6,MF being the other signals of channels S1 to S6, S1,HF tO S6,HF being the high frequency signals of channels S1 to S6, a being a proportionality coefficient. ### Claim 8 (depends on 1) The acoustic system according to claim 1, wherein: the acoustic system is designed for diffusing the sound from a stereo source, the channels comprising a left channel L and a right channel R; the number M of loudspeakers is equal to four, the loudspeakers comprising a first loudspeaker HP1 receiving a first loudspeaker signal SS1, a second loudspeaker HP2 receiving a second loudspeaker signal SS2, a third loudspeaker HP3 receiving a third loudspeaker signal SS3, and a fourth loudspeaker HP4 receiving a fourth loudspeaker signal SS4; and the splitter is configured so that: SS1=a*[½*LMF+SSLF+SSHF], SS2=a*[½*RMF+SSLF+SSHF], SS3=a*[½*LMF+SSLF+SSHF], and SS4=a*[½*RMF+SSLF+SSHF], with SSLF=¼*(LLF+RLF) and SSHF=¼*(LHF+RHF), LLF being the low frequency signal of the left channel L, LMF being the other signal of the left channel L, LHF being the high frequency signal of the left channel L, RLF being the low frequency signal of the right channel R, RMF being the other signal of the right channel R, RHF being the high frequency signal of the right channel R, a being a proportionality coefficient. ### Claim 9 (depends on 1) The acoustic system according to claim 1, wherein: the acoustic system is designed for diffusing the sound from a source with five channels S1 to S5 and one channel S6 with no audio frequencies that are higher than the first frequency; the number M of loudspeakers is equal to four, the loudspeakers including a first loudspeaker HP1 receiving a first loudspeaker signal SS1, a second loudspeaker HP2 receiving a second loudspeaker signal SS2, a third loudspeaker HP3 receiving a third loudspeaker signal SS3, and a fourth loudspeaker HP4 receiving a fourth loudspeaker signal SS4; and the splitter is adapted such that: SS1=a*[1*S3,MF+¼*S1,MF+¼*S2,MF+SSLF+SSHF], SS2=a*[¾*S1,MF+½*S4,MF+SSLF+SSHF], SS3=a*[½*S4,MF+½*S5,MF+SSLF+SSHF], and SS4=a*[¾*S2,MF+½*S5,MF+SSLF+SSHF], with SSLF=¼*(S1,LF+S2,LF+S3,LF+S4,LF+S5,LF+S5,LF+S6,LF), and SSHF=¼*(S1,HF+S2,HF+S3,HF+S4,HF+S5,HF+S5,LF), S1,LF to S6,LF being the low frequency signals of channels S1 to S6, with S6,LF=S6, S1,MF to S6,MF being the other signals of channels S1 to S6, S1,HF to S6,HF being the high frequency signals of channels S1 to S6, a being a proportionality coefficient. ### Claim 10 A method for diffusing sound from N channels comprising audio frequencies, N being greater than or equal to two, the method comprising: providing M loudspeakers structurally similar to each other and mounted on a same frame, M being greater than or equal to two, the loudspeakers being arranged at an angle around an axis intended to be substantially vertical, two successive loudspeakers forming an angle substantially equal to 360° divided by M, sending, by a processing unit, M loudspeaker signals respectively to the loudspeakers, and generating the loudspeaker signals by a splitter of the processing unit, each loudspeaker signal produced having a shared bass component obtained from at least one of the channels, and in which audio frequencies that are higher than a predetermined first frequency are non-existent or reduced, at least two of the loudspeaker signals further comprising a specific component in addition to the shared bass component and in which audio frequencies below the first frequency are non-existent or reduced, each specific component being obtained from at least one of the channels, and at least two of the specific components being different from each other selecting frequencies in order to produce, from each channel, on the one hand a low frequency signal in which the audio frequencies of the channel higher than the first frequency are non-existent or reduced, and on the other hand, if said channel comprises audio frequencies that are higher than the first frequency, at least one other signal in which the audio frequencies of the channel lower than the first frequency are non-existent or reduced, the shared bass component being proportional to the sum of the low frequency signals, the specific components being obtained from the other signals, extracting, from each respective channel comprising audio frequencies that are higher than a predetermined second frequency, a high-frequency signal in which the audio frequencies of said channel lower than the second frequency are non-existent or reduced, the second frequency being higher than the first frequency, the frequency selector being configured so that, in each of the other signals, the audio frequencies that are higher than the second frequency are non-existent or reduced; and at least one of the loudspeaker signals formed by the splitter further comprises a shared high frequency component proportional to the sum of the high frequency signals, the shared high frequency component being added to the shared bass component. ### Claim 11 (depends on 1) The acoustic system according to claim 1, wherein all the loudspeaker signals formed by the splitter further comprise a shared high frequency component proportional to the sum of the high frequency signals, the shared high frequency component being added to the shared bass component.