Automatic audio system equalizing

• US 7,483,540 B2
• Filed: 03/25/2002
• Issued: 01/27/2009
• Est. Priority Date: 03/25/2002
• Status: Active Grant

• Current Assignee: Bose Corporation
• Original Assignee: Bose Corporation
• Inventors: Kulkarni, Abhijit, Arnold, Finn, Saffran, Richard E., Lehnert, Hilmar, Martin, Keith D., Rabinowitz, William M.
• Primary Examiner(s): Lee; Ping
• Application Number:
  US10/105,206
• Publication Number:
  US 20030179891A1
• Time in Patent Office: 2,500 Days
• Field of Search: 381/58, 381/103, 381/98, 381/99, 381/108, 381/56, 381/59, 381/95, 381/96
• US Class Current: 381/103
• CPC Class Codes: H04R 2205/024 Positioning of loudspeaker enclosures for spatial sound reproduction
• CPC Class Codes: H04R 2430/01 Aspects of volume control, not necessarily automatic, in sound systems
• CPC Class Codes: H04R 29/001 for loudspeakers H04R29/007 takes precedence
• CPC Class Codes: H04R 29/002 Loudspeaker arrays
• CPC Class Codes: H04R 3/04 for correcting frequency response
• CPC Class Codes: H04R 3/12 for distributing signals to two or more loudspeakers specially adapted for hearing aids H04R25/407
• CPC Class Codes: H04S 7/301 Automatic calibration of stereophonic sound system, e.g. with test microphone
• CPC Class Codes: H04S 7/307 Frequency adjustment, e.g. tone control H04S7/301 takes precedence

Abstract

An automated process for equalizing an audio system and an apparatus for implementing the process. An audio system includes a microphone unit, for receiving the sound waves radiated from a plurality of speakers, acoustic measuring circuitry, for providing frequency response measurement signals; a memory, for storing characteristic data signals representative of the loudspeaker units and further for storing the frequency response measurement signals; and equalization calculation circuitry, for providing an equalization pattern signal responsive to the frequency response measurement signals and responsive to the characteristic data signals representative of the plurality of loudspeaker units. Also described is an automated equalizing system including acoustic measuring circuitry including a microphone for providing frequency signals representative of responses at a plurality of locations; a memory, for storing the signals representative of frequency responses at the plurality of locations; and equalization calculation circuitry responsive to the signals representative of the frequency responses for providing an equalization pattern signal.

Claims

1. An audio system, comprising:

a source of audio signals;

signal processing circuitry coupled to said source for processing said audio signals to produce processed audio signals;

a plurality of loudspeaker units, coupled to said signal processing circuitry, constructed and arranged to be deployed about a room, for radiating sound waves responsive to said processed audio signals;

a microphone unit, for receiving said sound waves and for transducing said sound waves to electrical signals;

acoustic measuring circuitry, for receiving said electrical signals and providing frequency response signals;

a memory, coupled to said acoustic measuring circuitry, for storing characteristic data signals of said loudspeaker units and further for storing said frequency response signals; and

equalization calculation circuitry, comprising a microprocessor running a software program wherein said software program is constructed and arranged to automatically validate at least one of a first frequency response or a second frequency response by causing the source of audio signals to cause radiation of a first sound wave from a first of the plurality of loudspeaker units to produce the first frequency response at a first location and then radiation of a second sound wave from said first of the plurality of loudspeaker units to produce the second frequency response at said first location and comparing the first and second frequency responses, said equalization calculation circuitry coupled to said memory, for providing an individual equalization pattern signal for each loudspeaker unit responsive to said frequency response signals and said characteristic data signals of an associated one of said plurality of loudspeaker units.

2. An audio system in accordance with claim 1, wherein the coupling path between said microphone unit and said acoustic measuring circuitry comprises electrically conductive wire free of wireless portions.

3. An audio system in accordance with claim 1, wherein said microphone unit comprises a plurality of microphones.

4. An audio system in accordance with claim 1, wherein said equalization calculation circuitry is constructed and arranged to determine an equalization pattern that is substantially continuous with regard to frequency.

5. An audio system in accordance with claim 1, wherein said software program comprises code for causing audible instructions for said user to be radiated by at least one of said plurality of loudspeaker units.

6. An audio system in accordance with claim 1, wherein said microphone unit is adapted to be moved about said room to a plurality of positions, to transduce said sound waves received at each of said plurality of positions to produce a corresponding plurality of sets of frequency response signals;

wherein said memory is further for storing said plurality of sets of frequency response signals;

and wherein said equalization calculation circuitry is further for providing an equalization pattern signal responsive to said plurality of sets of frequency response signals.

7. An audio system in accordance with claim 6, wherein said equalization pattern signal is representative of the energy average of said frequency response measurements.

8. An audio system in accordance with claim 1, wherein said audio processing circuitry comprises low latency filters.

9. An audio system in accordance with claim 1, wherein at least one of said plurality of loudspeaker units comprises a plurality of acoustic driver units, and wherein said memory is further for storing characteristic data signals representative of said acoustic driver units.

10. An audio system in accordance with claim 1, wherein said equalization calculation circuitry is constructed and arranged to control at least one operating parameter of said audio system.

11. An audio system in accordance with claim 10, wherein said at least one operating parameter includes at least one of volume setting and tone setting.

12. An audio system in accordance with claim 10, wherein said equalizing calculation circuitry is constructed and arranged so that said equalizing calculation circuitry has exclusive control over said at least one operating parameter and so that user accessible controls of operating parameters are disabled.

13. An audio system in accordance with claim 1, wherein said software program is constructed and arranged to cause radiation of said first sound wave with a first intensity and said second sound wave of a second intensity different from said first intensity.

14. An audio system in accordance with claim 1 wherein said software program is constructed and arranged to cause radiation of said second sound wave after said microphone unit has been moved to another location.

15. An audio system in accordance with claim 1 wherein said software is constructed and arranged to disable time varying, nonlinear or signal dependent processing in said signal processing circuitry before radiation of said first and second sound waves.

16. An audio system in accordance with claim 1 wherein said software is constructed and arranged to cause said acoustic measuring circuitry to make an ambient noise measurement before radiation of said first and second sound waves.

17. An audio system, comprising:

a source of audio signals;

signal processing circuitry coupled to said source for processing said audio signals to produce processed audio signals;

a plurality of loudspeaker units, coupled to said signal processing circuitry, constructed and arranged to be deployed about a room, for radiating sound waves responsive to said processed audio signals;

acoustic measuring circuitry, including a microphone, for receiving said sound waves and providing signals representative of frequency responses of each loudspeaker unit at a plurality of locations;

a memory, coupled to said acoustic measuring circuitry, for storing characteristic data signals of said loudspeaker units and further for storing said signals representative of frequency responses at said plurality of locations; and

equalization calculation circuitry comprising a microprocessor running a software program wherein said software program is constructed and arranged to automatically validate at least one of a first frequency response or a second frequency response by causing the source of audio signals to cause radiation of a first sound wave from a first of the plurality of loudspeaker units to produce the first frequency response signal representative of a frequency response at a first location and then radiation of the second sound wave from said first of the plurality of loudspeaker units to produce a second frequency response signal representative of the frequency response at the first location and by comparing the first and second frequency response signals, said equalization calculation circuitry responsive to said signals representative of frequency response at said plurality of locations, and said characteristic data signals of an associated one of said plurality of loudspeaker units, for providing an individual equalization pattern signal for each loudspeaker unit.

18. An audio system in accordance with claim 17, wherein said equalization calculation circuitry is constructed and arranged to provide said signals representative of frequency responses at said plurality of locations for each of said loudspeaker units singly.

19. An audio system in accordance with claim 17, further comprising crossover circuitry coupling said signal processing circuitry and said plurality of loudspeaker units, wherein said memory is further for storing characteristic data signals representative of said crossover circuitry, and wherein said equalization calculation circuitry is further for providing an equalization pattern signal responsive to said characteristic data signals representative of said crossover circuitry.

20. An audio system in accordance with claim 17, wherein said software program is constructed and arranged to cause radiation of said first sound wave with a first intensity and said second sound wave of a second intensity different from said first intensity.

21. An audio system in accordance with claim 17 wherein said software program is constructed and arranged to cause radiation of said second sound wave after said microphone unit has been moved to another location.

22. An audio system in accordance with claim 17 wherein said software is constructed and arranged to disable time varying, nonlinear or signal dependent processing in said signal processing circuitry before radiation of said first and second sound waves.

23. An audio system in accordance with claim 17 wherein said software is constructed and arranged to cause said acoustic measuring circuitry to make an ambient noise measurement before radiation of said first and second sound waves.

24. An audio system comprising:

a source of audio signals;

signal processing circuitry coupled to said source for processing said audio signals to produce processed audio signals;

a plurality of loudspeaker units, coupled to said signal processing circuitry, constructed and arranged to be deployed about a room, for radiating sound waves responsive to said processed audio signals;

a microphone unit, for receiving said sound waves and for transducing said sound waves to electrical signals;

acoustic measuring circuitry, for receiving said electrical signals and providing frequency response signals;

a memory, coupled to said acoustic measuring circuitry, for storing characteristic data signals of said loudspeaker units and further for storing said frequency response signals; and

equalization calculation circuitry, comprising a microprocessor running a software program

wherein said software program is constructed and arranged to cause the source of audio signals to cause radiation of a first sound wave to produce a first frequency response and then radiation of a second sound wave to produce a second frequency response and compare the first and second frequency responses, said equalization calculation circuitry coupled to said memory, for providing an individual equalization pattern signal for each loudspeaker unit responsive to said frequency response signals and said characteristic data signals of an associated one of said plurality of loudspeaker units

wherein said software program is constructed and arranged to cause radiation of said first sound wave with a first intensity and said second sound wave of a second intensity different from said first intensity and

wherein said software program is constructed and arranged to further include scaling one of the first and second frequency responses by an amount corresponding to the difference between said first intensity and said second intensity to produce a scaled signal that is used for comparison between said first and second frequency responses to provide an indication that the amplitude is outside an acceptable range, ambient noise is above an acceptable limit or that the frequency responses are otherwise unacceptable.

25. An audio system comprising:

a source of audio signals;

signal processing circuitry coupled to said source for processing said audio signals to produce processed audio signals;

a plurality of loudspeaker units, coupled to said signal processing circuitry, constructed and arranged to be deployed about a room, for radiating sound waves responsive to said processed audio signals;

acoustic measuring circuitry, including a microphone, for receiving said sound waves and providing signals representative of frequency responses of each loudspeaker unit at a plurality of locations;

a memory, coupled to said acoustic measuring circuitry, for storing characteristic data signals of said loudspeaker units and further for storing said signals representative of frequency responses at said plurality of locations; and

equalization calculation circuitry comprising a microprocessor running a software program wherein said software program is constructed and arranged to cause the source of audio signals to cause radiation of a first sound wave to produce a first frequency response signal and then radiation of a second sound wave to produce a second frequency response signal and compare the first and second frequency response signals, said equalization calculation circuitry responsive to said signals representative of frequency response at said plurality of locations, and said characteristic data signals of an associated one of said plurality of loudspeaker units, for providing an individual equalization pattern signal for each loudspeaker unit;

wherein said software program is constructed and arranged to cause radiation of said first sound wave with a first intensity and said second sound wave of a second intensity different from said first intensity; and

wherein said software program is constructed and arranged to further include scaling one of the first and second frequency responses by an amount corresponding to the difference between said first intensity and said second intensity to produce a scaled signal that is used for comparison between said first and second frequency responses to provide an indication that the amplitude is outside an acceptable range, ambient noise is above an acceptable limit or that the frequency responses are otherwise unacceptable.

26. A method for operating an audio system, comprising:

receiving audio signals;

processing said audio signals to produce processed audio signals;

radiating, from a plurality of loudspeaker units, deployed about a room, sound waves responsive to said processed audio signals;

receiving said sound waves and transducing said sound waves to electrical signals;

receiving said electrical signals and providing frequency response signals;

calculating an equalization pattern, said calculating comprising

automatically validating at least one of a first frequency response or a second frequency response by causing the source of audio signals to cause radiation of a first sound wave from a first of the plurality of loudspeaker units to produce the first frequency response at a first location and then causing radiation of a second sound wave from said first of the plurality of loudspeaker units to produce the second frequency response at the first location and comparing the first and second frequency responses.

27. A method in accordance with claim 26, wherein the receiving said sound waves is performed by a plurality of microphones.

28. A method in accordance with claim 26, wherein said calculating said equalization pattern comprises calculating an equalization pattern that is substantially continuous with regard to frequency.

29. A method in accordance with claim 26,

wherein said receiving said sound waves comprises receiving said sound waves at a plurality of positions, and

wherein said calculating said equalization pattern comprises calculating an equalization pattern signal responsive to said sound waves received at said plurality of positions.

30. A method in accordance with claim 29, wherein said calculating said equalization pattern signal comprises calculating an energy average of said sound waves received at said plurality of positions.

31. A method in accordance with claim 26, wherein said audio processing comprises processing with latency filters.

32. A method in accordance with claim 26, further comprising storing characteristic data signals representative of said loudspeaker units.

33. A method in accordance with claim 26, further comprising controlling, by equalization calculation circuitry, at least one operating parameter of said audio system.

34. A method in accordance with claim 33, wherein said controlling comprises at least one of controlling volume setting and controlling tone setting.

35. A method in accordance with claim 33, wherein said controlling comprises exclusively controlling said at least one operating parameter and disabling user accessible controls of said operating parameters.