System and method for directionally radiating sound
First Claim
Patent Images
1. An audio system for use with multiple listening positions, said audio system comprising:
- at least one source of audio signals;
at least one respective array of speaker elements located at each of a plurality of the listening positions that receives the audio signals and responsively radiates bass frequency acoustic energy;
wherein, for each first at least one array at a first listening position of the plurality of listening positions,a first pair of speaker elements receive a common said audio signal,a filter is disposed between the common audio signal and at least one of the speaker elements of the first at least one array, wherein said filter processes the common audio signal and outputs a processed audio signal to the at least one speaker element, independently of application of the common signal to another of the pair of said elements of the first at least one array, andthe filter implements a set of coefficients for the filter to process audio signals to the at least one speaker element, and is optimized based on descent of a gradient of a cost function that compares bass frequency acoustic energy radiated from the first at least one array and detected at the first listening position and bass frequency acoustic energy radiated from the first at least one array and detected at least one listening position other than the first listening position, so that an acoustic isolation between the first listening position and the plurality of other listening positions, as a ratio of magnitude of the bass frequency acoustic energy radiated by the first at least one array to the plurality of listening positions other than the first listening position and magnitude of the bass frequency acoustic energy radiated by the first array to the first listening position, is greater than the acoustic isolation that would result if the signals applied to each of the first pair of speaker elements were equal in magnitude and opposite in polarity.
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Abstract
An audio system for a vehicle has at least one source of audio signals. At least one array of speaker elements is located at each seat position that radiates within a range of bass frequencies. For each at least one array, the speaker elements receive a common audio signal, and a respective filter is disposed between the common audio signal and each of the speaker elements. Each respective filter processes magnitude and phase of the common audio signal independently of each other respective filter to thereby define a directional audio radiation from the at least one array.
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Citations
28 Claims
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1. An audio system for use with multiple listening positions, said audio system comprising:
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at least one source of audio signals; at least one respective array of speaker elements located at each of a plurality of the listening positions that receives the audio signals and responsively radiates bass frequency acoustic energy; wherein, for each first at least one array at a first listening position of the plurality of listening positions, a first pair of speaker elements receive a common said audio signal, a filter is disposed between the common audio signal and at least one of the speaker elements of the first at least one array, wherein said filter processes the common audio signal and outputs a processed audio signal to the at least one speaker element, independently of application of the common signal to another of the pair of said elements of the first at least one array, and the filter implements a set of coefficients for the filter to process audio signals to the at least one speaker element, and is optimized based on descent of a gradient of a cost function that compares bass frequency acoustic energy radiated from the first at least one array and detected at the first listening position and bass frequency acoustic energy radiated from the first at least one array and detected at least one listening position other than the first listening position, so that an acoustic isolation between the first listening position and the plurality of other listening positions, as a ratio of magnitude of the bass frequency acoustic energy radiated by the first at least one array to the plurality of listening positions other than the first listening position and magnitude of the bass frequency acoustic energy radiated by the first array to the first listening position, is greater than the acoustic isolation that would result if the signals applied to each of the first pair of speaker elements were equal in magnitude and opposite in polarity. - View Dependent Claims (2, 3, 4, 5, 6, 7)
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8. An audio system for use with multiple listening positions, said audio system comprising:
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at least one source of audio signals; at least one respective array of speaker elements located at each of a plurality of the listening positions that receives the audio signals and responsively radiates bass frequency acoustic energy; wherein, for each first at least one array at a first listening position of the plurality of listening positions, the speaker elements receive a common said audio signal, a filter is disposed between the common audio signal and at least one of the speaker elements of the first at least one array, wherein the filter processes the common audio signal and outputs a processed audio signal to the at least one speaker element, independently of application of the common signal to another said speaker element of the first at least one array, and the filter processes audio signals to the at least one speaker element, and is optimized based on descent of a gradient of a cost function that compares bass frequency acoustic energy radiated from the first at least one array and detected at the first listening position and bass frequency acoustic energy radiated from the first at least one array and detected at least one listening position other than the first listening position, so that a ratio of magnitude of the bass frequency acoustic energy radiated by the first at least one array to the at least one listening position of the plurality of listening positions other than the first listening position and magnitude of the bass frequency acoustic energy radiated by the first at least one array to the first listening position meets a predetermined criteria for acoustic isolation. - View Dependent Claims (9, 10, 11, 12, 13, 14, 15, 16, 17)
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18. An audio system for use with multiple listening positions, said audio system comprising:
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at least one source of audio signals; at least one respective array of speaker elements located at each of a plurality of the listening positions that receives the audio signals and responsively radiates bass frequency acoustic energy; wherein, for each first at least one array at a first listening position of the plurality of listening positions, the speaker elements receive a common said audio signal, a filter is disposed between the common audio signal and at least one of two of the speaker elements of the first at least one array, wherein the filter processes the common audio signal and outputs a processed audio signal to the at least one speaker element, independently of application of the common signal to the other speaker element of the two speaker elements of the first at least one array, and the filter implements a set of coefficients that varies phase and/or magnitude of the bass frequency acoustic energy radiated by the at least one speaker element as a function of frequency of the common audio signal, and is optimized based on descent of a gradient of a cost function that compares bass frequency acoustic energy radiated from the first at least one array and detected at the first listening position and bass frequency acoustic energy radiated from the first at least one array and detected at least one listening position other than the first listening position, so that acoustic isolation arising from radiation of the bass frequency acoustic energy by the at least one respective array of speaker elements is greater at the at least one other listening position when the filter implements the predetermined set of coefficients than when the bass frequency acoustic energy radiated from the two speaker elements have approximately equal magnitude and are respectively approximately 180 degrees out of phase with respect to each other.
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19. A method for providing and operating an audio system for use with multiple listening positions, said audio system comprising:
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(a) providing at least one source of audio signals; (b) providing at least one respective array of speaker elements at each of a plurality of the listening positions that receives the audio signals and responsively radiates bass frequency acoustic energy, wherein, for each first at least one array at a first listening position of the plurality of listening positions, the speaker elements receive a common said audio signal; (c) determining a cost function that compares bass frequency acoustic energy radiated from the first at least one array and detected at the first listening position and bass frequency acoustic energy radiated from the first at least one array and detected at a second listening position of the plurality of listening positions; and (d) optimizing a filter between the common audio signal and at least one of the speaker elements of the first at least one array, wherein the filter processes the common audio signal and outputs a processed common audio signal to the at least one speaker element, independently of application of the common signal to another said speaker element of the first at least one array, based on descent of a gradient of the cost function so that the filter reduces a magnitude of acoustic energy radiated from the first array to the second listening position, compared to a magnitude of acoustic energy radiated from the first array to the first listening position. - View Dependent Claims (20)
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21. A method for providing and operating an audio system for use with multiple listening positions, said audio system comprising:
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(a) providing at least one source of audio signals; (b) providing at least one respective array of speaker elements at each of a plurality of the listening positions that receives the audio signals and responsively radiates bass frequency acoustic energy, wherein, for each first at least one array at a first listening position of the plurality of listening positions, the speaker elements receive a common said audio signal; (c) driving each of the speaker elements of the first array to radiate first said bass frequency acoustic energy; (d) detecting the first bass frequency acoustic energy at the first listening position; (e) detecting the first bass frequency acoustic energy at a second listening position of the plurality of listening positions; (f) optimizing, based on descent of a gradient of a cost function that compares the bass frequency acoustic energy detected at step (d) and the bass frequency acoustic energy detected at step (e), a filter between the common audio signal and at least one of the speaker elements of the first array, wherein the filter processes the common audio signal and outputs a processed common audio signal to the at least one speaker element, so that the filter reduces a magnitude of acoustic energy radiated from the first array to the second listening position, compared to a magnitude of acoustic energy radiated from the first array to the first listening position. - View Dependent Claims (22, 23, 24, 25, 26, 27, 28)
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Specification