# US 2014/0190763 A1 · Ported enclosure and automated equalization of frequency response in a micro-speaker audio system > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2014/0190763 A1 - Document ID: US20140190763A1 - Status: Published application - Kind: A1 - Application number: 14/105,074 - Filed: 2013-12-12 - Published: 2014-07-10 - Earliest claimed: 2013-01-07 - Assignees: NVIDIA Corporation - Applicants: Nvidia Corporation - Inventors: Nikhil SATISH; David DIGNAM - Web page: https://patentgrep.com/patent/US20140190763A1 ## CPC - H04R 3/04: for correcting frequency response - H04R 1/2888: {for loudspeaker transducers} - 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) ## Abstract One embodiment of the present invention sets forth a system that includes a detection device and a processor. The detection device is configured to sense that a handheld device has not been placed on or near a surface. In response to sensing that the handheld device has not been placed on or near a surface, the detection device is configured to transmit an indicator to the processor. The processor is configured to receive a first audio signal, and determine that the handheld device has not been placed on or near a surface by receiving the indicator from the detection device. In response to determining that the handheld device has not been placed on or near a surface, the processor is further configured to apply a compensating function to the first audio signal to generate a second audio signal, and transmit the second audio signal to a speaker. ## Claims ### Claim 1 A ported enclosure configured to house a micro-speaker, comprising: an enclosure comprising a port, wherein the enclosure is tuned to a first resonance frequency that is different from a second resonance frequency associated with the micro-speaker. ### Claim 2 (depends on 1) The ported enclosure of claim 1, wherein the first resonance frequency is based on at least one of a linear dimension associated with the port and a cross sectional area associated with the port. ### Claim 3 (depends on 1) The ported enclosure of claim 1, wherein the port comprises a circular cross-section and the first resonance frequency is based on at least one of a linear dimension associated with the port and a radius associated with the port. ### Claim 4 (depends on 1) The ported enclosure of claim 1, wherein a Q value of the first resonance frequency and a combined response of the micro-speaker and the port are based on a first resistance associated with the port. ### Claim 5 (depends on 4) The ported enclosure of claim 4, wherein the first resistance is inversely proportional to a cross sectional area associated with the port. ### Claim 6 (depends on 5) The ported enclosure of claim 5, wherein the cross sectional area associated with the port corresponds to a value for the first resistance that reduces at least one of audio distortion and cone displacement related to the micro-speaker at frequencies above the first resonance frequency. ### Claim 7 (depends on 5) The ported enclosure of claim 5, wherein the cross sectional area associated with the port corresponds to a value for the first resistance that reduces at least one of amplitude peaking, audio distortion, and cone displacement related to the micro-speaker at frequencies below the first resonance frequency. ### Claim 8 (depends on 4) The ported enclosure of claim 4 wherein the port comprises a circular cross-section and the first resistance is proportional to a square of the radius associated with the port. ### Claim 9 (depends on 1) The ported enclosure of claim 1, wherein the port has a length of approximately 30 mm and a radius of approximately 1.5 mm. ### Claim 10 (depends on 1) The ported enclosure of claim 1, wherein the port has a first end and a second end, and at least one of the first end and the second end is flared. ### Claim 11 (depends on 1) The ported enclosure of claim 1, wherein the first resonance frequency is approximately 300 Hz, and the second resonance frequency is approximately 270 Hz. ### Claim 12 A speaker module, comprising: a micro-speaker associated with a handheld device; and a ported enclosure configured to house the micro-speaker. ### Claim 13 (depends on 12) The speaker module of claim 12, wherein the ported enclosure comprises a port tuned to a first resonance frequency that is different from a second resonance frequency associated with the micro-speaker. ### Claim 14 (depends on 13) The speaker module of claim 13, wherein the first resonance frequency is based on at least one of a linear dimension associated with a port and a cross sectional area associated with the port. ### Claim 15 (depends on 13) The speaker module of claim 13, wherein the port comprises a circular cross-section and the first resonance frequency is based on at least one of a linear dimension associated with the port and a radius associated with the port. ### Claim 16 (depends on 13) The speaker module of claim 13, wherein a Q value of the first resonance frequency and a combined response of the micro-speaker and the port are based on a first resistance associated with the port. ### Claim 17 (depends on 16) The speaker module of claim 16, wherein the first resistance is inversely proportional to a cross sectional area associated with the port. ### Claim 18 (depends on 17) The speaker module of claim 17, wherein the cross sectional area associated with the port corresponds to a value for the first resistance that reduces at least one of amplitude peaking, audio distortion, and cone displacement related to the micro-speaker at frequencies below the first resonance frequency. ### Claim 19 (depends on 17) The speaker module of claim 17, wherein the port comprises a circular cross-section and the first resistance is proportional to a square of the radius associated with the port. ### Claim 20 A handheld device, comprising: a processor; and a speaker module comprising: a micro-speaker; and a ported enclosure configured to house the micro-speaker.