Statistical analysis of potential audio system configurations

• US 20050031135A1
• Filed: 10/10/2003
• Published: 02/10/2005
• Est. Priority Date: 08/04/2003
• Status: Active Grant

• Current Assignee: Harman International Industries Incorporated (Samsung Electronics Co. Ltd.)
• Original Assignee: Harman International Industries Incorporated (Samsung Electronics Co. Ltd.)
• Inventors: Devantier, Allan O., Welti, Todd S.
• Granted Patent: US 8,705,755 B2
• Time in Patent Office: Days
• US Class Current: 381/59
• CPC Class Codes: H04R 2499/13 Acoustic transducers and sound field adaptation in vehicles
• CPC Class Codes: H04R 27/00 Public address systems circuits for preventing acoustic reaction H04R3/02; circuits for distributing signals to loudspeakers H04R3/12; monitoring or testing arrangements for public address systems H04R29/007; amplifiers H03F
• CPC Class Codes: H04R 29/007 for public address systems public address systems per se H04R27/00
• CPC Class Codes: H04S 7/301 Automatic calibration of stereophonic sound system, e.g. with test microphone
• CPC Class Codes: H04S 7/302 Electronic adaptation of stereophonic sound system to listener position or orientation H04S7/301 takes precedence
• CPC Class Codes: H04S 7/307 Frequency adjustment, e.g. tone control H04S7/301 takes precedence

Abstract

A system is provided for configuring an audio system for a given space. The system may statistically analyze potential configurations of the audio system to configure the audio system. The potential configurations may include positions of the loudspeakers, numbers of loudspeakers, types of loudspeakers, listening positions, correction factors, or any combination thereof. The statistical analysis may indicate at least one metric of the potential configuration including indicating consistency of predicted transfer functions, flatness of the predicted transfer functions, differences in overall sound pressure level from seat to seat for the predicted transfer functions, efficiency of the predicted transfer functions, or the output of predicted transfer functions. The system also provides a methodology for selecting loudspeaker locations, the number of loudspeakers, the types of loudspeakers, correction factors, listening positions, or a combination of these schemes in an audio system that has a single listening position or multiple listening positions.

Claims

1. A method for selecting a configuration for an audio system, the method comprising:

generating acoustic signals from at least one loudspeaker placed at potential loudspeaker locations;

recording transfer functions for the generated acoustic signals at a plurality of listening positions;

determining potential configurations of the audio system;

modifying the transfer functions based on the potential configurations in order to generate predicted transfer functions;

statistically analyzing across at least one frequency of the predicted transfer functions for the plurality of listening positions; and

selecting a configuration based on the statistical analysis.

2. The method of claim 1, where the configuration comprises at least one parameter that affects acoustical performance of the audio system;

where determining potential configurations comprises determining potential values for the parameter;

where modifying the transfer functions comprises modifying the transfer functions based on the potential values for the parameter; and

where selecting a configuration comprises selecting a value for the parameter.

3. The method of claim 2, where determining potential values for the parameter comprises inputting potential values for the parameter.

4. The method of claim 2, where the configuration comprises at least two parameters that affect acoustical performance of the audio system;

and

where determining potential configurations of the audio system comprises determining potential combinations of potential values of the parameters.

5. The method of claim 2, where the parameter is selected from the group consisting of positions of the loudspeakers, number of loudspeakers, types of loudspeakers, and correction factors.

6. The method of claim 2, where the parameter comprises positions of the loudspeakers;

and

where determining potential configurations comprises;

determining potential positions of the loudspeakers; and

generating potential combinations of speakers based on the potential positions of the loudspeakers; and

where modifying the transfer functions comprises superpositioning of the transfer functions based on the potential combinations of speakers.

7. The method of claim 6, where the at least one parameter further comprises correction factors;

and

where the potential configurations are based on the potential combinations of speakers and the potential values for the correction factors.

8. The method of claim 1, where recording transfer functions at a plurality of listening positions comprises placing a microphone at each of the listening positions and recording the transfer functions.

9. The method of claim 1, where the statistical analysis is across a plurality of frequencies of the predicted transfer functions.

10. The method of claim 9, where the plurality of frequencies are less than 120 Hz.

11. The method of claim 1, where the statistical analysis is selected from the group consisting of mean spatial variance, mean spatial standard deviation, mean spatial envelope, and mean spatial maximum average.

12. The method of claim 1, where the statistical analysis comprises mean spatial variance.

13. The method of claim 12, where the mean spatial variance is based on an average of spatial variance across the listening positions for a plurality of frequencies.

14. The method of claim 1, where selecting a configuration comprises automatically recommending a plurality of potential configurations and manually selecting one of the plurality of potential configurations.

15. A machine readable medium having software for causing a machine to execute a method, the machine readable medium comprising:

instructions for generating acoustic signals from at least one loudspeaker placed at potential loudspeaker locations;

instructions for recording transfer functions for the generated acoustic signals at a plurality of listening positions;

instructions for determining potential configurations of the audio system;

instructions for modifying the transfer functions based on the potential configurations in order to generate predicted transfer functions;

instructions for statistically analyzing across at least one frequency of the predicted transfer functions for the plurality of listening positions.

16. The machine readable medium of claim 15, where the instructions for recording transfer functions comprise instructions for storing the transfer functions in a memory.

17. The machine readable medium of claim 15, where the instructions for determining potential configurations comprise instructions for inputting potential values for at least one parameter for the audio system.

18. The machine readable medium of claim 17, where the audio system comprises at least two parameters that affect acoustical performance;

and

where the instructions for determining potential configurations of the audio system comprise instructions for determining potential combinations of potential values of the parameters.

19. The machine readable medium of claim 15, where the statistical analysis is across a plurality of frequencies of the predicted transfer functions.

20. The machine readable medium of claim 19, where the plurality of frequencies are less than 120 Hz.

21. The machine readable medium of claim 15, where the statistical analysis is selected from the group consisting of mean spatial variance, mean spatial standard deviation, mean spatial envelope, and mean spatial maximum average.

22. The machine readable medium of claim 15, where the statistical analysis comprises mean spatial variance.

23. The machine readable medium of claim 22, where the mean spatial variance is based on an average of spatial variance across the listening positions for a plurality of frequencies.

24. The machine readable medium of claim 15, further comprising instructions for recommending a plurality of potential configurations.

25. A computer system for analyzing potential configurations in an audio system, the computer system comprising:

a memory storing transfer functions recorded at a plurality of listening positions in the audio system; and

a processor in communication with the memory, the processor determining potential configurations of the audio system, modifying the transfer functions based on the potential configurations in order to generate predicted transfer functions, statistically analyzing across at least one frequency of the predicted transfer functions, and recommending at least one of the potential configurations based on the statistical analysis.

26. The computer system of claim 25, where the statistical analysis comprises mean spatial variance.

27. A method for selecting a configuration for an audio system, the method comprising:

recording transfer functions at at least one listening position in the audio system;

determining potential configurations of the audio system;

modifying the transfer functions based on the potential configurations in order to generate predicted transfer functions;

statistically analyzing the predicted transfer functions; and

selecting a configuration based on the statistical analysis.

28. The method of claim 27, where the configuration comprises at least one parameter that affects acoustical performance of the audio system;

where determining potential configurations comprises determining potential values for the parameter;

where modifying the transfer functions comprises modifying the transfer functions based on the potential values for the parameter; and

where selecting a configuration comprises selecting a value for the parameter.

29. The method of claim 28, where the parameter is selected from the group consisting of positions of the loudspeakers, number of loudspeakers, types of loudspeakers, and correction factors.

30. The method of claim 27, where the transfer functions measure at least one acoustical property of the audio system.

31. The method of claim 30, where the transfer function measures amplitude and phase at a single frequency or multiple frequencies.

32. The method of claim 27, where the loudspeaker is a subwoofer.

33. The method of claim 27, where the audio system comprises a plurality of loudspeakers.

34. The method of claim 27, where the configuration comprises potential loudspeaker locations;

and

where recording transfer functions comprises generating acoustic signals from the loudspeaker placed at each of the potential loudspeaker locations; and

recording the transfer functions for the listening position for the generated acoustic signals.

35. The method of claim 34, where generating acoustic signals from the loudspeaker placed at each of the potential loudspeaker locations comprises placing the loudspeaker at a first potential position and controlling the audio system to generate an acoustic signal;

and

where recording transfer functions at the plurality of listening positions comprises placing a microphone at a first listening position and recording the acoustic signal and placing the microphone at a second listening position and recording the acoustic signal.

36. The method of claim 27, where recording transfer functions comprises recording transfer functions for a plurality of listening positions.

37. The method of claim 28, where determining potential values for the parameter comprises selecting a discrete number of potential configurations.

38. The method of claim 28, where determining potential values for the parameter comprises selecting a range of potential values.

39. The method of claim 28, where the parameter comprises loudspeaker locations;

where recording transfer functions comprises recording transfer functions at the listening position with the loudspeaker in each of the plurality of potential loudspeaker locations;

where determining potential configurations comprises inputting a plurality of potential loudspeaker locations and determining potential combinations of the potential loudspeaker locations; and

where modifying the transfer functions comprises combining the transfer functions for the listening position for each of the potential combinations of loudspeaker locations to generate the predicted transfer functions.

40. The method of claim 39, where the plurality of loudspeaker locations comprises a first potential loudspeaker location and a second potential loudspeaker location;

where recording transfer functions comprises;

recording a first transfer function at a first listening position with the loudspeaker at the first potential loudspeaker location;

recording a second transfer function at the first listening position with the loudspeaker at the second potential loudspeaker location;

recording a third transfer function at a second listening position with the loudspeaker at the first potential loudspeaker location; and

recording a fourth transfer function at the second listening position with the loudspeaker at the second potential loudspeaker location;

where combining the transfer functions comprises;

combining the first transfer function and the second transfer function; and

combining the third transfer function and the fourth transfer function;

where statistically analyzing the predicted transfer functions is based on the first transfer function, the second transfer function, the third transfer function, the fourth transfer function, the combined first and second transfer function and the combined third and fourth transfer function.

41. The method of claim 40, where combining the first transfer function and the second transfer function comprises performing superposition of the first transfer function with the second transfer function;

and

where combining the third transfer function and the fourth transfer function comprises performing superposition of the third transfer function with the fourth transfer function.

42. The method of claim 27, where the configuration comprises number of loudspeakers;

where potential configurations comprise potential numbers of loudspeakers; and

where modifying the transfer functions based on the potential configurations comprises;

determining potential combinations of loudspeakers at potential loudspeaker locations, the potential combinations being equal to at least one of the potential number of loudspeakers; and

combining the transfer functions for each of the potential combinations to generate predicted transfer functions for each of the potential combinations.

43. The method of claim 28, where the parameter comprises types of loudspeakers;

where determining potential configurations comprises determining combinations of potential types of loudspeakers at potential loudspeaker locations;

where recording transfer functions comprises recording transfer functions at the listening position with each potential type of loudspeaker in each of the plurality of potential loudspeaker locations; and

where modifying the transfer functions based on the potential configurations comprises combining the transfer functions for the listening position for each of the combinations to generate predicted transfer functions.

44. The method of claim 43, where the types of loudspeakers comprises loudspeakers with different qualities.

45. The method of claim 44, where the potential types of loudspeakers comprise a dipole loudspeaker and a monopole loudspeaker.

46. The method of claim 27, where the configuration comprises correction factors;

where potential configurations comprise potential values for the correction factors; and

where modifying the transfer functions based on the potential configurations comprises modifying the transfer functions for potential values for the correction factors to generate predicted transfer functions for each of the potential values.

47. The method of claim 46, where the correction factors comprise gain, delay, and equalization.

48. The method of claim 27, where the configuration comprises a plurality of parameters;

where determining potential configurations comprises determining potential values for the plurality of parameters and determining potential combinations of the potential values of the parameters;

where recording transfer functions comprises recording transfer functions at the listening position with each type of potential loudspeaker in each of a plurality of potential loudspeaker locations; and

where modifying the transfer functions based on the potential configurations comprises modifying the transfer functions based on the potential combinations to generate predicted transfer functions.

49. The method of claim 27, where statistically analyzing the predicted transfer functions comprises analyzing frequencies of the predicted transfer functions below about 120 Hz.

50. The method of claim 27, where recording the transfer functions comprises recording the transfer functions at a plurality of listening positions;

and

where statistically analyzing the predicted transfer functions comprises analyzing the predicted transfer functions across the plurality of listening positions.

51. The method of claim 50, where analyzing the predicted transfer functions across the plurality of listening positions is a function of frequency.

52. The method of claim 27, where recording the transfer functions comprises recording the transfer functions at a plurality of listening positions;

and

where statistically analyzing the predicted transfer functions comprises analyzing the predicted transfer functions for each of the plurality of listening positions.

53. The method of claim 27, where recording the transfer functions comprises recording the transfer functions at a plurality of listening positions;

and

where the statistical analysis indicates consistency of the predicted transfer functions across the plurality of listening positions.

54. The method of claim 27, where recording the transfer functions comprises recording the transfer functions at a plurality of listening positions;

and

where the statistical analysis is selected from the group consisting of mean spatial variance, mean spatial standard deviation, mean spatial envelope, and mean spatial maximum average.

55. The method of claim 27, where recording the transfer functions comprises recording the transfer functions at a plurality of listening positions;

and

where the statistical analysis comprises mean spatial variance.

56. The method of claim 55, where the mean spatial variance is based on an average of spatial variance across the listening positions for a plurality of frequencies.

57. The method of claim 27, where the statistical analysis indicates flatness of the predicted transfer functions.

58. The method of claim 27, where recording the transfer functions comprises recording the transfer functions at a plurality of listening positions;

and

where the statistical analysis is selected from the group consisting of variance of spatial average, standard deviation of the spatial average, envelope of the spatial average, and variance of the spatial minimum.

59. The method of claim 27, where the statistical analysis is selected from the group consisting of amplitude variance and amplitude standard deviation.

60. The method of claim 27, where recording the transfer functions comprises recording the transfer functions at a plurality of listening positions;

and

where the statistical analysis indicates differences in overall sound pressure level among the plurality of listening positions for the predicted transfer functions.

61. The method of claim 27, where recording the transfer functions comprises recording the transfer functions at a plurality of listening positions;

and

where the statistical analysis is selected from the group consisting of variance of mean levels;

standard deviation of mean levels, envelope of mean levels, and maximum average of mean levels.

62. The method of claim 27, where recording the transfer functions comprises recording the transfer functions at a plurality of listening positions;

and

where the statistical analysis indicates efficiency of the predicted transfer functions at the plurality of listening positions.

63. The method of claim 62, where efficiency is examined for predetermined frequencies.

64. The method of claim 63, where selecting a configuration based on the statistical analysis comprises selecting a value for a parameter to increase efficiency of the audio system in the predetermined frequencies.

65. The method of claim 64, where the parameter comprises volume correction;

and

where selecting a value to increase efficiency comprises selecting a value that decreases the volume of at least one of the loudspeakers in the audio system.

66. The method of claim 27, where the statistical analysis comprises acoustic efficiency.

67. The method of claim 66, where the acoustic efficiency comprises a mean overall level divided by a total drive level for the predicted transfer function.

68. The method of claim 66, where selecting a configuration based on the statistical analysis comprises selecting a value for a parameter to increase acoustic efficiency of the audio system.

69. The method of claim 68, where the parameter comprises volume correction;

and

where selecting a value to increase acoustic efficiency comprises selecting a value that decreases the volume of at least one of the loudspeakers in the audio system.

70. The method of claim 27, where recording the transfer functions comprises recording the transfer functions at a plurality of listening positions;

and

where the statistical analysis indicates output of predicted transfer functions at the multiple listening positions.

71. The method of claim 70, where output is examined for predetermined frequencies.

72. The method of claim 71, where selecting a configuration based on the statistical analysis comprises selecting a value for a parameter to increase output of the audio system in the predetermined frequencies.

73. The method of claim 72, where the parameter comprises volume correction;

and

where selecting a value to increase output comprises selecting a value that decreases the volume of at least one of the loudspeakers in the audio system.

74. The method of claim 27, where recording the transfer functions comprises recording the transfer functions at a plurality of listening positions;

and

where the statistical analysis comprises mean overall level.

75. The method of claim 27, where selecting a configuration comprises selecting one of the potential values of the parameter.

76. The method of claim 27, where selecting a configuration comprises manually selecting a configuration.

77. The method of claim 27, where selecting a configuration comprises automatically selecting a configuration.

78. The method of claim 77, where a plurality of statistical analyses are performed;

and

where selecting a configuration is based on weighting the plurality of statistical analyses.

79. The method of claim 27, where the statistical analysis ranks the predicted transfer functions based on at least one metric, and

where selecting a configuration comprises selecting a configuration based on the ranking.

80. The method of claim 79, where selecting a configuration based on the ranking comprises selecting an optimal value based on a highest ranked predicted transfer function.

81. A machine readable medium having software for causing a machine to execute a method, the machine readable medium comprising:

instructions for storing transfer functions recorded at at least one listening position in an audio system;

instructions for determining potential configurations for the audio system;

instructions for modifying the transfer functions based on the potential configurations in order to generate predicted transfer functions; and

instructions for statistically analyzing the predicted transfer functions.

82. The machine readable medium of claim 81, where the instructions for determining potential configurations comprise instructions for receiving input for potential values of parameters for the audio system.

83. The machine readable medium of claim 81, where the potential configurations comprise a plurality of potential loudspeaker locations;

where the transfer functions are recorded with the loudspeaker in each of the plurality of potential loudspeaker locations;

where the instructions for determining potential configurations for the audio system comprise instructions for determining potential combinations of the potential loudspeaker locations; and

where the instructions for modifying the transfer functions based on the potential configurations comprise instructions for combining the transfer functions for the listening position for each of the potential combinations of loudspeaker locations to generate predicted transfer functions.

84. The machine readable medium of claim 81, where the potential configurations comprise potential values for the correction factors;

where the instructions for modifying the transfer functions based on the potential configurations comprise instructions for modifying the transfer functions for potential values for the correction factors to generate predicted transfer functions for each of the potential values.

85. The machine readable medium of claim 84, where the correction factors comprise gain, delay, and equalization.

86. The machine readable medium of claim 81, where the configuration comprises a plurality of parameters;

where the instructions for determining potential configurations comprise instructions for inputting potential values for the plurality of parameters and instructions for determining potential combinations of the potential values of the parameters;

where the instructions for recording transfer functions comprise instructions for recording transfer functions at each of a plurality of listening positions with each type of potential loudspeaker in each of a plurality of potential loudspeaker locations; and

where the instructions for modifying the transfer functions based on the potential configurations comprise instructions for modifying the transfer functions based on the potential combinations to generate predicted transfer functions for the potential combinations.

87. The machine readable medium of claim 81, where the instructions for statistically analyzing the predicted transfer functions comprise instructions for analyzing frequencies of the predicted transfer functions below about 120 Hz.

88. The machine readable medium of claim 81, where the instructions for recording the transfer functions comprise instructions for recording the transfer functions at a plurality of listening positions;

and

where the instructions for statistically analyzing the predicted transfer functions comprise instructions for analyzing the predicted transfer functions across the plurality of listening positions.

89. The method of claim 88, where the instructions for analyzing the predicted transfer functions across the plurality of listening positions is as a function of frequency.

90. The machine readable medium of claim 81, where the instructions for recording the transfer functions comprise instructions for recording the transfer functions at a plurality of listening positions;

and

where the instructions for statistically analyzing the predicted transfer functions comprise instructions for analyzing the predicted transfer functions for each of the plurality of listening positions.

91. The machine readable medium of claim 81, where the instructions for recording the transfer functions comprise instructions for recording the transfer functions at a plurality of listening positions;

and

where the statistical analysis indicates flatness of the predicted transfer functions across the plurality of listening positions.

92. The machine readable medium of claim 81, where the statistical analysis is selected from the group consisting of mean spatial variance, mean spatial standard deviation, mean spatial envelope, and mean spatial maximum average.

93. The machine readable medium of claim 81, where the statistical analysis comprises mean spatial variance.

94. The machine readable medium of claim 81, where the statistical analysis indicates how much equalization is necessary for the predicted transfer functions.

95. The machine readable medium of claim 81, where the statistical analysis is selected from the group consisting of variance of spatial average, standard deviation of the spatial average, envelope of the spatial average, and variance of the spatial minimum.

96. The machine readable medium of claim 81, where the instructions for recording the transfer functions comprise instructions for recording the transfer functions at a plurality of listening positions;

and

where the statistical analysis indicates differences in overall sound pressure level among the plurality of listening positions for the predicted transfer functions.

97. The machine readable medium of claim 81, where the statistical analysis is selected from the group consisting of variance of mean levels, standard deviation of mean levels, envelope of mean levels, and maximum average of mean levels.

98. The machine readable medium of claim 81, where the instructions for recording the transfer functions comprise instructions for recording the transfer functions at a plurality of listening positions;

and

where the statistical analysis indicates efficiency of the predicted transfer functions at the plurality of listening positions.

99. The machine readable medium of claim 81, where the statistical analysis comprises acoustic efficiency.

100. The machine readable medium of claim 81, where the statistical analysis comprises mean overall level.

101. The machine readable medium of claim 81, further comprising instructions for recommending at least one of the potential configurations.

102. The machine readable medium of claim 101, where a plurality of statistical analyses are performed;

and

where the instructions for recommending at least one of the potential configurations is based on weighting the plurality of statistical analyses.

103. The machine readable medium of claim 101, where the instructions for the statistical analysis ranks the predicted transfer functions based on at least one metric, and

where the instructions for recommending a configuration comprise recommending a configuration based on ranking the at least one metric.

104. The machine readable medium of claim 103, where the instructions for recommending a configuration based on the ranking comprise instructions for recommending an optimal value based on a highest ranked predicted transfer function.

105. A signal-bearing medium having software for causing a machine to execute a method, the signal-bearing medium comprising:

logic for storing transfer functions recorded at at least one listening position in an audio system;

logic for determining potential configurations for the audio system;

logic for modifying the transfer functions based on the potential configurations in order to generate predicted transfer functions; and

logic for statistically analyzing the predicted transfer functions.

106. A computer-data signal embodied in a carrier wave, the computer-data signal comprising:

code segment for recording transfer functions at at least one listening position in an audio system;

code segment for determining potential configurations for the audio system;

code segment for modifying the transfer functions based on the potential configurations in order to generate predicted transfer functions; and

code segment for statistically analyzing the predicted transfer functions.

107. In an audio system comprising at least one loudspeaker and a plurality of listening positions, a system for analyzing potential configurations comprising:

means for storing transfer functions recorded at at least one listening position;

means for determining potential configurations for the audio system;

means for modifying the transfer functions based on the potential configurations in order to generate predicted transfer functions; and

means for statistically analyzing the predicted transfer functions.

108. The system of claim 107, where means for recording potential configurations for the audio system comprises means for recording parameters for the configurations, the parameters selected from the group consisting of positions of the loudspeakers, number of loudspeakers, types of loudspeakers, and correction factors.

109. The system of claim 107, where means for storing transfer functions comprises means for storing transfer functions recorded at a plurality of listening positions;

and

where means for statistically analyzing comprises means for analyzing the predicted transfer functions across the plurality of listening positions.

110. The system of claim 109, where means for statistically analyzing comprises means for calculating the mean spatial variance.

111. In an audio system comprising at least one loudspeaker and a plurality of listening positions, a system for analyzing potential configurations comprising:

storage means for storing transfer functions recorded at the plurality of listening positions; and

processor means for determining potential configurations for the audio system, for modifying the transfer functions based on the potential configurations in order to generate predicted transfer functions, and for statistically analyzing the predicted transfer functions.

112. The system of claim 111, where the processor means further recommends at least one of the potential configurations based on the statistical analysis.

113. The system of claim 111, where the statistical analysis is across at least one frequency of the predicted transfer functions.

114. A computer system for analyzing potential configurations in an audio system comprising:

a memory storing transfer functions recorded at a plurality of listening positions in the audio system; and

a processor determining potential configurations for the audio system, modifying the transfer functions based on the potential configurations in order to generate predicted transfer functions, and statistically analyzing the predicted transfer functions.

115. The computer system of claim 114, where the processor further recommends at least one of the potential configurations based on the statistical analysis.

116. The computer system of claim 114, where the statistical analysis is across at least one frequency of the predicted transfer functions.