# US 2020/0288246 A1 · Management of low frequency components of an audio signal at a mobile computing device > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2020/0288246 A1 - Document ID: US20200288246A1 - Status: Published application - Kind: A1 - Application number: 16/809,146 - Filed: 2020-03-04 - Published: 2020-09-10 - Earliest claimed: 2019-03-05 - Assignees: Maxim Integrated Products, Inc. - Applicants: Maxim Integrated Products, Inc. - Inventors: Robert Polleros; Vivek P. Nigam - Web page: https://patentgrep.com/patent/US20200288246A1 ## CPC - H04R 5/02: Spatial or constructional arrangements of loudspeakers - 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)} - 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 3/04: for correcting frequency response - H04R 3/14: Cross-over networks - 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)} - H04S 1/007: {in which the audio signals are in digital form (data reduction aspects thereof based on psychoacoustics G10L19/02)} - H04S 7/30: {Control circuits for electronic adaptation of the sound field} - H04M 1/03: Constructional features of telephone transmitters or receivers, e.g. telephone hand-sets - H04M 1/725: Cordless telephones (user interfaces specially adapted therefor H04M1/724) - H04R 2499/11: Transducers incorporated or for use in hand-held devices, e.g. mobile phones, PDA's, camera's - 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 - H04M: TELEPHONIC COMMUNICATION (circuits for controlling other apparatus via a telephone cable and not involving telephone switching apparatus G08) ## Abstract A mobile computing device includes a digital signal processor, a first speaker having a first sensitivity and a second speaker having a second sensitivity, where the second sensitivity is greater than the first sensitivity. The digital signal processor includes an audio signal manager that is configured to receive an audio signal having first and second channel signals, partition the first channel signal into a first high frequency signal and a first low frequency signal, partition the second channel signal into a second high frequency signal and a second low frequency signal, generate a mono low frequency signal based on the first and second low frequency signals, partition the mono low frequency signal into first and second mono low frequency signals based on an excursion limit of the second speaker, generate a first composite channel signal based on the first high frequency signal and the first mono low frequency signal for playback by the first speaker, and generate a second composite channel signal based on the second high frequency signal and the second mono low frequency signal for playback by the second speaker. ## Claims ### Claim 1 A mobile computing device comprising: a first speaker having a first sensitivity; a second speaker having a second sensitivity, the second sensitivity being greater than the first sensitivity; and an audio signal manager configured to: receive an audio signal having first and second channel signals; partition the first channel signal into a first high frequency signal and a first low frequency signal; partition the second channel signal into a second high frequency signal and a second low frequency signal; generate a mono low frequency signal based on the first and second low frequency signals; partition the mono low frequency signal into first and second mono low frequency signals based on an excursion limit of the second speaker; generate a first composite channel signal based on the first high frequency signal and the first mono low frequency signal for playback by the first speaker; and generate a second composite channel signal based on the second high frequency signal and the second mono low frequency signal for playback by the second speaker. ### Claim 2 (depends on 1) The mobile computing device of claim 1, further comprising a digital signal processor, the audio signal manager being a component of the digital signal processor. ### Claim 3 (depends on 1) The mobile computing device of claim 1, further comprising a portable energy source configured to supply power to the first and second speakers. ### Claim 4 (depends on 1) The mobile computing device of claim 1, wherein the mobile computing device comprises a mobile phone. ### Claim 5 (depends on 1) The mobile computing device of claim 1, wherein the first speaker comprises a micro speaker of a mobile phone and the second speaker comprises a receiver speaker of a mobile phone. ### Claim 6 (depends on 1) The mobile computing device of claim 1, wherein the audio signal manager comprises: a first high pass filter configured to receive the first channel signal and generate the first high frequency signal; a first low pass filter configured to receive the first channel signal and generate the first low frequency signal; a second high pass filter configured to receive the second channel signal and generate the second high frequency signal; and a second low pass filter configured to receive the second channel signal and generate the second low frequency signal. ### Claim 7 (depends on 1) The mobile computing device of claim 1, wherein the first low frequency signal comprises a bass component of the first channel signal and the second low frequency signal comprises a bass component of the second channel signal. ### Claim 8 (depends on 1) The mobile computing device of claim 1, wherein the audio signal manager comprises a mono signal generator configured to receive the first and second low frequency signals as an input and generate the mono low frequency signal. ### Claim 9 (depends on 1) The mobile computing device of claim 1, wherein the audio signal manager comprises a mono signal partitioner configured to receive the mono low frequency signal as an input and generate the first and second mono low frequency signals based on an excursion amplitude threshold associated with the excursion limit of the second speaker. ### Claim 10 (depends on 1) The mobile computing device of claim 1, wherein the audio signal manager comprises a composite signal generator configured to: receive the first high frequency signal and the first mono low frequency signal as inputs and generate the first composite channel signal; and receive the second high frequency signal and the second mono low frequency signal as inputs and generate the second composite channel signal. ### Claim 11 A mobile computing device comprising: a first speaker having a first sensitivity; a second speaker having a second sensitivity, the second sensitivity being greater than the first sensitivity, the second speaker further having an excursion limit; and an audio signal manager configured to: receive an audio signal having first and second channel signals; partition the first channel signal into a first high frequency signal and a first low frequency signal; partition the second channel signal into a second high frequency signal and a second low frequency signal; generate a mono low frequency signal based on the first and second low frequency signals; partition the mono low frequency signal into first and second mono low frequency signals based on the excursion limit, the first mono low frequency signal comprising a portion of the mono low frequency signal that is above the excursion limit and the second low frequency signal comprising a portion of the mono low frequency signal that is within the excursion limit; generate a first composite channel signal based on the first high frequency signal and the first mono low frequency signal for playback by the first speaker; and generate a second composite channel signal based on the second high frequency signal and the second mono low frequency signal for playback by the second speaker. ### Claim 12 (depends on 11) The mobile computing device of claim 11, wherein the audio signal manager comprises: a first high pass filter configured to receive the first channel signal and generate the first high frequency signal; a first low pass filter configured to receive the first channel signal and generate the first low frequency signal; a second high pass filter configured to receive the second channel signal and generate the second high frequency signal; and a second low pass filter configured to receive the second channel signal and generate the second low frequency signal. ### Claim 13 (depends on 11) The mobile computing device of claim 11, wherein the first low frequency signal comprises a bass component of the first channel signal and the second low frequency signal comprises a bass component of the second channel signal. ### Claim 14 (depends on 11) The mobile computing device of claim 11, wherein the audio signal manager comprises a mono signal generator configured to receive the first and second low frequency signals as an input and generate the mono low frequency signal. ### Claim 15 (depends on 11) The mobile computing device of claim 11, wherein the audio signal manager comprises a mono signal partitioner configured to receive the mono low frequency signal as an input and generate the first and second mono low frequency signals based on an excursion amplitude threshold associated with the excursion limit of the second speaker. ### Claim 16 (depends on 11) The mobile computing device of claim 11, wherein the audio signal manager comprises a composite signal generator configured to: receive the first high frequency signal and the first mono low frequency signal as inputs and generate the first composite channel signal; and receive the second high frequency signal and the second mono low frequency signal as inputs and generate the second composite channel signal. ### Claim 17 A digital signal processor for a mobile computing device including an audio signal manager comprising: at least one processor; and at least one memory comprising computer program code, the at least one memory and the computer program code configured to, with the at least one processor, to cause the audio signal manager to: receive an audio signal having first and second channel signals; partition the first channel signal into a first high frequency signal and a first low frequency signal; partition the second channel signal into a second high frequency signal and a second low frequency signal; generate a mono low frequency signal based on the first and second low frequency signals; partition the mono low frequency signal into first and second mono low frequency signals based on an excursion limit of a first speaker; generate a first composite channel signal based on the first high frequency signal and the first mono low frequency signal for playback by the first speaker; and generate a second composite channel signal based on the second high frequency signal and the second mono low frequency signal for playback by a second speaker, wherein a sensitivity of the first speaker is greater than a sensitivity of the second speaker. ### Claim 18 (depends on 17) The digital signal processor of claim 17, wherein the at least one processor causes the audio signal manager to generate the first and second composite channel signals for playback by a receiver speaker of a mobile phone and a micro speaker of the mobile phone respectively. ### Claim 19 (depends on 17) The digital signal processor of claim 17, wherein the first low frequency signal comprises a bass component of the first channel signal and the second low frequency signal comprises a bass component of the second channel signal. ### Claim 20 (depends on 19) The digital signal processor of claim 19, wherein the at least one processor causes the audio signal manager to partition the mono low frequency signal into first and second mono low frequency signals based on an excursion amplitude threshold associated with the excursion limit of the first speaker.