Vehicle sound system

• US 20030219137A1
• Filed: 01/08/2003
• Published: 11/27/2003
• Est. Priority Date: 02/09/2001
• Status: Active Grant

• Current Assignee: Slot Speaker Technologies, Inc.
• Original Assignee: THX Limited (Razer Incorporated)
• Inventors: Fincham, Lawrence R.
• Granted Patent: US 7,457,425 B2
• Time in Patent Office: Days
• US Class Current: 381/302
• CPC Class Codes: H04R 2205/022 Plurality of transducers corresponding to a plurality of sound channels in each earpiece of headphones or in a single enclosure
• CPC Class Codes: H04R 2499/13 Acoustic transducers and sound field adaptation in vehicles
• CPC Class Codes: H04R 5/02 Spatial or constructional arrangements of loudspeakers
• CPC Class Codes: 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
• CPC Class Codes: 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

Abstract

A vehicle sound system encompasses a combination of speaker configuration, speaker placement, and sound processing to improve sound quality. A pair of speakers (or rows of speakers) are placed close together and located in the front of the console or dashboard with their geometric center on or near the vehicle'"'"'s central axis. A sound processor acts to “spread” the sound image produced by the two closely spaced speakers by employing a cross-cancellation technique in which the cancellation signal is derived from the difference between the left and right channels. The resulting difference signal is scaled, delayed (if necessary), and spectrally modified before being added in opposite polarities to the left and right channels. The pair of speakers may be placed on a common baffle or mounting surface or in a common housing enclosure, with sound being carried through one or more ducts and emanating out of a slot.

Claims

1. A vehicle sound system, comprising:

a pair of speakers in close proximity within a vehicle; and

a sound processor receiving as inputs a left channel audio signal and a right channel audio signal from an audio source, said sound processor configured to mix a spectrally weighted difference signal with said left channel audio signal and said right channel audio signal, and to output a resulting modified left channel audio signal and modified right channel audio signal to said pair of speakers.

2. The vehicle sound system of claim 1, wherein the modified left channel audio signal and modified right channel audio signal cause said pair of speakers to generate a widened sound image.

3. The vehicle sound system of claim 1, wherein said pair of speakers comprises a left speaker and a right speaker.

4. The vehicle sound system of claim 3, wherein said sound processor mixes said spectrally weighted difference signal with said left channel audio signal and said right channel audio signal by cross-canceling said spectrally weighted difference signal with said left channel audio signal and said right channel audio signal, respectively.

5. The vehicle sound system of claim 3, wherein said left speaker and said right speaker are positioned substantially on or near a center axis of the vehicle.

6. The vehicle sound system of claim 3, wherein said left speaker and said right speaker are located immediately adjacent to one another.

7. The vehicle sound system of claim 1, wherein said pair of speakers are mounted on a common speaker mounting structure.

8. The vehicle sound system of claim 7, wherein said speaker mounting structure is adapted for placement within the vehicle such that said pair of speakers are enclosed within an interior structure of the vehicle, and wherein at least one sound duct carries sound from said pair of speakers to an orifice located on the interior structure of the vehicle.

9. The vehicle sound system of claim 8, wherein said orifice comprises a slot oriented in a horizontal direction, wherein said at least one sound duct extends into the interior structure of the vehicle from said slot, is elongate, and approximately conforms to the height and width dimensions of said slot.

10. The vehicle sound system of claim 9, wherein said pair of speakers are oriented such that their diaphragms face a reflecting surface of said at least one sound duct.

11. The vehicle sound system of claim 10, wherein said pair of speakers are oriented such that their diaphragms are substantially parallel with the elongate length of said at least one sound duct.

12. The vehicle sound system of claim 10, wherein said pair of speakers are both oriented either in a downwards or upwards direction.

13. The vehicle sound system of claim 8, further comprising a sound-damping material residing within said at least one sound duct and opposite said orifice, wherein each of said pair of speakers comprises a speaker cone having a rear portion opposite said orifice, and wherein said sound-damping material generally conforms to outer contours of the rear portions of the cones of said pair of speakers.

14. The vehicle sound system of claim 8, wherein said at least one sound duct comprises two sound ducts, one sound duct for each of said pair of speakers.

15. The vehicle sound system of claim 14, wherein said pair of speakers comprises a left speaker and a right speaker, the sound system further comprising a first additional left speaker in series along the same sound duct as the left speaker and further removed from said orifice, and a second additional right speaker in series along the same sound duct as the right speaker and further removed from said orifice.

16. The vehicle sound system of claim 15, wherein the modified left channel audio signal is applied to said left speaker with a first delay relative to said additional left speaker such that destructive interference between said left speaker and said additional left speaker is reduced, and wherein the modified right channel audio signal is applied to said right speaker with a second delay relative to said additional right speaker such that destructive interference between said right speaker and said additional right speaker is reduced.

17. The vehicle sound system of claim 16, wherein said left speaker and right speaker are symmetrically positioned with respect to said orifice, wherein said additional left speaker and said additional right speaker are symmetrically positioned with respect to said orifice, and wherein first delay and said second delay are equal.

18. The vehicle sound system of claim 15, further comprising at least one additional speaker located in proximity to said pair of speakers.

19. The vehicle sound system of claim 18, wherein said at least one additional speaker outputs sound through a portion of said orifice.

20. The vehicle sound system of claim 18, wherein said at least one additional speaker is oriented directly towards the interior of the vehicle.

21. The vehicle sound system of claim 1, further comprising a pair of door-mounted left and right speakers receiving versions of said left channel audio signal and said right channel audio signal, respectively.

22. The vehicle sound system of claim 21, wherein the door-mounted left speaker receives at least a portion of a difference between the left channel audio signal and the right channel audio signal, and wherein the door-mounted right speaker receives at least a portion of a difference between the right channel audio signal and the left channel audio signal.

23. The vehicle sound system of claim 1, wherein said sound processor is configured to generate a difference signal representing a difference between said left channel audio signal and said right channel audio signal, apply a spectral weighting to said difference signal thereby generating a spectrally weighted signal, and cross-cancel said spectrally weighted signal with said left channel audio signal and said right channel audio signal, thereby generating said modified left channel audio signal and modified right channel audio signal for said pair of speakers.

24. A vehicle sound system, comprising:

a left speaker and a right speaker located in close proximity; and

a sound processor receiving as inputs a left channel audio signal and a right channel audio signal, said sound processor configured to cross-cancel a spectrally weighted stereo difference signal with said left channel audio signal and said right channel audio signal and to output a resulting modified left channel audio signal and modified right channel audio signal to said left speaker and said right speaker, respectively, thereby effectively widening a sound image produced by said left speaker and said right speaker.

25. The vehicle sound system of claim 24, wherein said left speaker and said right speaker are positioned substantially on or near a center axis of a vehicle.

26. The vehicle sound system of claim 25, wherein said left speaker and said right speaker center-to-center separation is less than one foot.

27. The vehicle sound system of claim 24, wherein said left speaker and said right speaker are mounted on a common mounting surface.

28. The vehicle sound system of claim 27, further comprising a sound reflecting surface opposite said left speaker and said right speaker and collectively with at least said speaker mounting surface defining at least one sound duct terminating in an orifice, such that acoustic output from said pair of speakers is emitted from the orifice after being carried through said at least one sound duct.

29. The vehicle sound system of claim 28, wherein said orifice comprises a slot, and wherein said right speaker and said left speaker are oriented such that their acoustic output is emitted in a direction substantially perpendicular to a lengthwise direction of said at least one sound duct.

30. The vehicle sound system of claim 29, wherein said pair of speakers are both oriented either in a downwards or upwards direction.

31. The vehicle sound system of claim 28, further comprising a sound-damping material residing within said at least one sound duct and opposite said orifice, wherein each of said left speaker and right speaker comprises a speaker cone having a rear portion located furthest from said orifice, and wherein said sound-damping material generally conforms to outer contours of the rear portions of the cones of said left speaker and right speaker.

32. The vehicle sound system of claim 28, wherein said at least one sound duct comprises two sound ducts, one sound duct for each of said left speaker and said right speaker.

33. The vehicle sound system of claim 32, wherein said two sound ducts are separated by sound-damping material.

34. The vehicle sound system of claim 28, further comprising a first additional left speaker in series along the same sound duct as the left speaker and further removed from said orifice, and a second additional right speaker in series along the same sound duct as the right speaker and further removed from said orifice.

35. A method of sound reproduction for the interior of a vehicle, the method comprising the steps of:

positioning a left speaker and a right speaker in close proximity within a vehicle;

receiving a left channel audio signal and a right channel audio signal from an audio source, said left channel audio signal and right channel audio signal being stereo in nature; and

processing said left channel audio signal and said right channel audio signal and generating a modified left channel audio signal and modified right channel audio signal thereby, such that applying said modified left channel audio signal and modified right channel audio signal to said left speaker and right speaker, respectively, results in a widened sound image.

36. The method of claim 35, wherein the step of processing said left channel audio signal and said right channel audio signal comprises the step of mixing a spectrally weighted difference signal with said left channel audio signal and said right channel audio signal.

37. The method of claim 36, wherein said step of mixing a spectrally weighted difference signal with said left channel audio signal and said right channel audio signal comprises the steps of obtaining a difference signal representing a difference between said left channel audio signal and said right channel audio signal, spectrally weighting said difference signal, and cross-canceling the spectrally weighted difference signal from the left channel audio signal and the right channel audio signal.

38. The method of claim 35, wherein said left speaker and said right speaker are positioned substantially on or near a center axis of the vehicle.

39. The method of claim 38, wherein said left speaker and said right speaker have cones facing a same direction and located adjacent to one another.

40. The method of claim 38, further comprising the step of mounting said pair of speakers on a common speaker mounting structure.

41. The method of claim 40, further comprising the steps of

placing said speaker mounting structure within the vehicle such that said pair of speakers are enclosed within an interior structure of the vehicle, and

providing at least one sound duct which carries sound from said pair of speakers to an orifice located on the interior structure of the vehicle.

42. The method of claim 41, wherein said orifice comprises a slot oriented in a horizontal direction, wherein said at least one sound duct extends into the interior structure of the vehicle from said slot, is elongate, and approximately conforms to the height and width dimensions of said slot.

43. The method of claim 42, wherein said pair of speakers are oriented such that their diaphragms are substantially parallel with the elongate length of said at least one sound duct.

44. The method of claim 42, wherein each of said pair of speakers comprises a speaker cone having a rear portion opposite said orifice, and wherein the method further comprises the step of providing sound-damping material within said at least one sound duct and opposite said orifice, said sound-damping material generally conforming to outer contours of the rear portions of the cones of said pair of speakers.

45. The method of claim 35, further comprising the steps of placing a first additional left speaker in series with the left speaker and further removed from said orifice, and placing a second additional right speaker in series with the right speaker and further removed from said orifice.

46. The method of claim 45, further comprising the steps of applying the modified left channel audio signal to said left speaker with a first delay relative to said additional left speaker such that destructive interference between said left speaker and said additional left speaker is reduced, and applying the modified right channel audio signal to said right speaker with a second delay relative to said additional right speaker such that destructive interference between said right speaker and said additional right speaker is reduced.

47. The method of claim 46, wherein said left speaker and right speaker are symmetrically positioned with respect to said orifice, wherein said additional left speaker and said additional right speaker are symmetrically positioned with respect to said orifice, and wherein first delay and said second delay are equal.

48. The method of claim 41, further comprising the step of placing at least one additional speaker in proximity to said left speaker and said right speaker

49. The method of claim 48, wherein said at least one additional speaker outputs sound through at least a portion of said orifice.

50. The method of claim 35, further comprising the step of mounting left and right bass speakers in left and right doors of the vehicle, said left and right bass speakers receiving low-pass filtered versions of said left channel audio signal and said right channel audio signal, respectively.

51. A vehicle sound system, comprising:

a speaker mounting assembly adapted for placement in a vehicle console or dash, said speaker mounting assembly comprising

a speaker mounting surface;

a pair of speakers disposed upon said speaker mounting surface, said pair of speakers comprising a left speaker and a right speaker; and

a sound reflecting surface opposite said pair of speakers and collectively with at least said speaker mounting surface defining a sound duct terminating in an orifice, such that acoustic output from said pair of speakers is emitted from the orifice after being carried through the sound duct;

a sound processor receiving as inputs a left channel audio signal and a right channel audio signal from an audio source, and to output a modified left channel audio signal and modified right channel audio signal to said pair of speakers.

52. The vehicle sound system of claim 51, wherein said sound processor configured to mix a spectrally weighted difference signal with said left channel audio signal and said right channel audio signal in order to generate said modified left channel audio signal and modified right channel audio signal to said pair of speakers.

53. The vehicle sound system of claim 51, wherein said left speaker and said right speaker are positioned in close proximity.

54. The vehicle sound system of claim 51, wherein said sound duct comprises one or more interior walls formed of sound-damping material.

55. The vehicle sound system of claim 54, wherein said sound-damping material comprises compressed foam.

56. The vehicle sound system of claim 55, wherein the compressed foam is sandwiched between the speaker mounting surface and the sound reflecting surface of said speaker assembly.

57. A vehicle speaker system, comprising:

a left speaker and a right speaker having sound radiating openings in close proximity; and

a sound processor receiving as inputs a left channel audio signal and a right channel audio signal, said sound processor outputting a modified left channel audio signal and modified right channel audio signal to said left speaker and said right speaker, respectively, thereby widening a sound image collectively produced by said left speaker and said right speaker.

58. The vehicle speaker system of claim 57, further comprising a pair of sound ducts terminating in said sound radiating openings.

59. The vehicle speaker system of claim 57, wherein said left speaker and right speaker each comprise a cone terminating in said sound radiating openings.