Variable acoustics loudspeaker

• US 10,728,666 B2
• Filed: 08/31/2017
• Issued: 07/28/2020
• Est. Priority Date: 08/31/2016
• Status: Active Grant

• Current Assignee: Harman International Industries Incorporated (Samsung Electronics Co. Ltd.)
• Original Assignee: Harman International Industries Incorporated (Samsung Electronics Co. Ltd.)
• Inventors: Horbach, Ulrich
• Primary Examiner(s): Goins, Davetta W
• Assistant Examiner(s): Ganmavo, Kuassi A
• Application Number:
  US16/329,411
• Publication Number:
  US 20190200132A1
• Time in Patent Office: 1,062 Days
• CPC Class Codes: G10K 11/32 characterised by the shape of the source
• CPC Class Codes: G10K 11/341 Circuits therefor
• CPC Class Codes: H04R 1/26 Spatial arrangements of separate transducers responsive to two or more frequency ranges
• CPC Class Codes: H04R 1/40 by combining a number of identical transducers specially adapted for hearing aids H04R25/405
• CPC Class Codes: H04R 1/403 loud-speakers
• CPC Class Codes: H04R 2201/401 2D or 3D arrays of transducers
• CPC Class Codes: H04R 2203/12 Beamforming aspects for stereophonic sound reproduction with loudspeaker arrays
• CPC Class Codes: H04R 2430/03 Synergistic effects of band splitting and sub-band processing
• 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 7/302 Electronic adaptation of stereophonic sound system to listener position or orientation H04S7/301 takes precedence

Abstract

A first array of speaker elements is disposed in a cylindrical configuration about an axis and configured to play back audio at a first range of frequencies. A second array of speaker elements is disposed in a cylindrical configuration about the axis and configured to play back audio at a second range of frequencies. A digital signal processor generates a first plurality of output channels from an input channel for the first frequencies, applies the output channels to the first array of speaker elements using a first rotation matrix to generate a first beam of audio content at a target angle about the axis, generates a second plurality of output channels from the input channel for the second frequencies, and applies the second output channels to the second array of speaker elements using a second rotation matrix to generate a second beam of audio content at the target angle.

Claims

1. A system comprising:

a first array of M speaker elements disposed in a cylindrical configuration about an axis and configured to play back audio at a first range of frequencies;

a second array of N speaker elements disposed in a cylindrical configuration about the axis and configured to play back audio at a second range of frequencies; and

a digital signal processor, programmed to

generate a first plurality of output channels from an input channel for the first range of frequencies,

apply the first plurality of output channels to the first array of speaker elements using a first rotation matrix to generate a first beam of audio content at a target angle about the axis,

generate a second plurality of output channels from the input channel for the second range of frequencies, and

apply the second plurality of output channels to the second array of speaker elements using a second rotation matrix to generate a second beam of audio content at the target angle about the axis,

wherein the first rotation matrix includes weighting factors of each of the first plurality of output channels to each of the M speaker elements, the second rotation matrix includes weighting factors of each of the second plurality of output channels to each of the N speaker elements, and a head element of the first array is defined according to the formula head=1+ang div M/360 degrees, where θ

=ang modulo M/360 degrees, β

=θ

/(M/360 degrees), and α

=1−

β

, such that

the head element receives output weighted by α

from a first output channel of the first plurality of output channels and output weighted by β

from a second output channel of the first plurality of output channels, and

elements of the first array adjacent to the head element receive output weighted by α

from a second output channel of the first plurality of output channels and output weighted by β

from a third output channel of the first plurality of output channels.

2. The system of claim 1, wherein, in response to a change in the target angle to a new target angle about the axis, the digital signal processor is programmed to:

update the weighting factors of the first rotation matrix to apply the first plurality of output channels to the first array of speaker elements to generate the first beam of audio content at the new target angle about the axis, and

update the weighting factors of the second rotation matrix to apply the second plurality of output channels to the second array of speaker elements to generate the second beam of audio content at the new target angle about the axis.

3. The system of claim 1, wherein M and N are positive integers and have different values from one another.

4. The system of claim 1, wherein the first plurality of distinct output channels is generated using a first set of finite input response filters, and the second plurality of distinct output channels is generated using a second set of finite input response filters.

5. The system of claim 4, wherein the first set of finite input response filters includes a first subset of finite input response filters corresponding to a first beam width and a second subset of finite input response filters corresponding to a second beam width, the second set of finite input response filters includes a third subset of finite input response filters corresponding to the first beam width and a fourth subset of finite input response filters corresponding to the second beam width,

the digital signal processor is programmed to select the first and third subsets of finite input response filters responsive to selection of the first beam width, and

the digital signal processor is programmed to select the second and fourth subsets of finite input response filters responsive to selection of the second beam width.

6. The system of claim 4, wherein a first of the first set of finite input response filters is configured to generate a first output channel for a first speaker element of the first array of speaker elements at the target angle, a second of the first set of finite input response filters is configured to generate a second output channel for second and third speaker elements of the first array of speaker elements adjacent to the first speaker element, and a third of the first set of finite input response filters is configured to generate a third output channel for fourth and fifth speaker elements of the first array of speaker elements adjacent to the second and third speaker elements.

7. The system of claim 6, wherein a first of the second set of finite input response filters is configured to generate a first output channel for a first speaker element of the second array of speaker elements at the target angle, a second of the second set of finite input response filters is configured to generate a second output channel for second and third speaker elements of the second array of speaker elements adjacent to the first speaker element, and a third of the second set of finite input response filters is configured to generate a third output channel for fourth and fifth speaker elements of the second array of speaker elements adjacent to the second and third speaker elements.

8. A method comprising:

generating a first plurality of output channels from an input channel for a first range of frequencies;

applying the first plurality of output channels, to a first array of M speaker elements disposed in a cylindrical configuration about an axis and playing back audio at a first range of frequencies, using a first rotation matrix to generate a first beam of audio content at a target angle about the axis;

generating a second plurality of output channels from the input channel for the second range of frequencies; and

applying the second plurality of output channels, to a second array of N speaker elements disposed in a cylindrical configuration about the axis and playing back audio at a second range of frequencies, using a second rotation matrix to generate a second beam of audio content at the target angle about the axis,

wherein the first rotation matrix includes weighting factors of each of the first plurality of output channels to each of the M speaker elements, the second rotation matrix includes weighting factors of each of the second plurality of output channels to each of the N speaker elements, and a head element of the first array is defined according to the formula head=1+ang div M/360 degrees, where θ

=ang modulo M/360 degrees, β

=θ

/(M/360 degrees), and α

=1−

β

, such that

the head element receives output weighted by α

from a first output channel of the first plurality of output channels and output weighted by β

from a second output channel of the first plurality of output channels, and

elements of the first array adjacent to the head element receive output weighted by α

from a second output channel of the first plurality of output channels and output weighted by β

from a third output channel of the first plurality of output channels.

9. The method of claim 8, further comprising, in response to a change in the target angle to a new target angle about the axis:

updating the weighting factors of the first rotation matrix to apply the first plurality of output channels to the first array of speaker elements to generate the first beam of audio content at the new target angle about the axis, and

updating the weighting factors of the second rotation matrix to apply the second plurality of output channels to the second array of speaker elements to generate the second beam of audio content at the new target angle about the axis.

10. The method of claim 8, wherein M and N are positive integers and have different values from one another.

11. The method of claim 8, wherein the first plurality of distinct output channels is generated using a first set of finite input response filters, and the second plurality of distinct output channels is generated using a second set of finite input response filters.

12. The method of claim 11, wherein the first set of finite input response filters includes a first subset of finite input response filters corresponding to a first beam width and a second subset of finite input response filters corresponding to a second beam width, the second set of finite input response filters includes a third subset of finite input response filters corresponding to the first beam width and a fourth subset of finite input response filters corresponding to the second beam width, and further comprising

selecting the first and third subsets of finite input response filters responsive to selection of the first beam width;

and

selecting the second and fourth subsets of finite input response filters responsive to selection of the second beam width.

13. The method of claim 11, wherein a first of the first set of finite input response filters is configured to generate a first output channel for a first speaker element of the first array of speaker elements at the target angle, a second of the first set of finite input response filters is configured to generate a second output channel for second and third speaker elements of the first array of speaker elements adjacent to the first speaker element, and a third of the first set of finite input response filters is configured to generate a third output channel for fourth and fifth speaker elements of the first array of speaker elements adjacent to the second and third speaker elements.

14. The method of claim 13, wherein a first of the second set of finite input response filters is configured to generate a first output channel for a first speaker element of the second array of speaker elements at the target angle, a second of the second set of finite input response filters is configured to generate a second output channel for second and third speaker elements of the second array of speaker elements adjacent to the first speaker element, and a third of the second set of finite input response filters is configured to generate a third output channel for fourth and fifth speaker elements of the second array of speaker elements adjacent to the second and third speaker elements.