Rotationally symmetric speaker array

Patent metadata

Field	Value
Publication number	US-10154339-B2
Application number	US-201715583949-A
Country	US
Kind code	B2
Filing date	May 1, 2017
Priority date	Aug 18, 2014
Publication date	Dec 11, 2018
Grant date	Dec 11, 2018

Abstract

A multi-way speaker array is disclosed that includes rings of transducers of different types. The rings of transducers may encircle the cabinet of the speaker array such that the speaker array is rotationally symmetric. The distance between rings of transducers may be based on a logarithmic scale. By separating rings of transducers using logarithmic spacing, denser transducer spacing at short wavelengths is achieved while limiting the number of transducers needed for longer wavelengths by spacing them in larger and larger logarithmic increments. Transducers with overlapping frequency ranges may be used in the speaker array to avoid initial dips or shortfalls in directivity for corresponding beam patterns.

First claim

What is claimed is:

1. A multi-way speaker array, comprising:
a cylindrical cabinet for holding a plurality of transducers, wherein the cylindrical cabinet is rotationally symmetric about a center axis;
a first ring of transducers arranged along a surface of the cylindrical cabinet around the center axis;
a second ring of transducers arranged along the surface of the cylindrical cabinet around the center axis; and
an end transducer arranged on an end of the cylindrical cabinet and facing a direction of the center axis;
wherein a first spacing between the first ring of transducers and the second ring of transducers in the direction of the center axis is different than a second spacing between the second ring of transducers and the end transducer in the direction of the center axis.

2. The multi-way speaker array of claim 1 , further comprising:
a third set of third transducers arranged in a third set of rings along the surface of the cylindrical cabinet around the center axis and surrounding the second ring of transducers such that an equal number of rings of the third set of rings are positioned on each side of the second ring of transducers.

3. The multi-way speaker array of claim 1 , further comprising:
a third set of third transducers arranged on one or more ends of the cylindrical cabinet and including the end transducer pointed perpendicular to the first and second rings of transducers.

4. The multi-way speaker array of claim 3 , wherein the first ring of transducers is selected to produce audio frequencies in a first frequency range, the second ring of transducers is selected to produce audio frequencies in a second frequency range, and the end transducer is selected to produce audio frequencies in a third frequency range.

5. The multi-way speaker array of claim 4 ,
wherein the audio frequencies in the first frequency range overlap with the audio frequencies in the second frequency range; and
wherein the audio frequencies in the second frequency range overlap with the audio frequencies in the third frequency range.

6. The multi-way speaker array of claim 1 , wherein a center of each transducer in the first ring of transducers is aligned with a center of a transducer in the second ring of transducers to form N uniform columns of transducers, wherein the uniform columns of transducers encircle the cylindrical cabinet such that the multi-way speaker array is rotationally symmetric on an order of N.

7. A method for driving one or more types of transducers in a speaker array, comprising:
receiving, by the speaker array, a first segment of an audio signal during a first time period, wherein the first segment has a frequency range;
detecting that the frequency range includes a first frequency;
determining that the first frequency falls within a frequency overlap between a first frequency range of a first transducer and a second frequency range of a second transducer within the speaker array, wherein the second frequency range of the second transducer is different than the first frequency range of the first transducer, wherein the first transducer is in a first ring of transducers arranged around a center axis and the second transducer is in a second ring of transducers arranged around the center axis, and wherein a first spacing between the first ring of transducers and the second ring of transducers in a direction of the center axis is different than a second spacing between the second ring of transducers and the end transducer in the direction of the center axis; and
driving, in response to determining that the first frequency falls within the frequency overlap, the speaker array to generate a first beam pattern using the first transducer and the second transducer.

8. The method of claim 7 , further comprising:
receiving, by the speaker array, a second segment of the audio signal during a second time period, wherein the second segment includes a respective frequency range;
detecting that the respective frequency range includes a second frequency;
determining that the second frequency falls within the first frequency range of the first transducer and not within the second frequency range of the second transducer; and
driving, in response to determining that the second frequency falls outside the frequency overlap, the speaker array to continue to generate the first beam pattern using the first transducer and not the second transducer.

9. A multi-way speaker array, comprising:
a cylindrical cabinet for holding a plurality of transducers, wherein the cylindrical cabinet is rotationally symmetric about a center axis;
a first set of first transducers arranged in a first ring along an outer surface of the cylindrical cabinet around the center axis, wherein each of the first transducers has a first frequency range; and
a second set of second transducers arranged in a second ring along the outer surface of the cylindrical cabinet around the center axis, wherein each of the second transducers has a second frequency range different than the first frequency range, and wherein the second ring is spaced from the first ring in a direction of the center axis by a first vertical distance; and
a third transducer having a third frequency range different than the first frequency range and the second frequency range, wherein the third transducer is spaced from the second ring in the direction of the center axis by a second vertical distance greater than the first vertical distance.

10. The multi-way speaker array of claim 9 , wherein each of the first transducers is spaced relative to adjacent transducers in the first ring by a first distance along the outer surface of the cylindrical cabinet, wherein each of the second transducers is spaced relative to adjacent transducers in the second ring by a second distance along the outer surface of the cylindrical cabinet, wherein the second distance is greater than the first distance, wherein the second set of second transducers is arranged in a second set of rings including the second ring and surrounding the first ring such that an equal number of rings of the second set of second transducers are positioned on each side of the first ring, and further comprising:
a third set of third transducers including the third transducer and arranged in a third set of rings along the outer surface of the cylindrical cabinet around the center axis and surrounding the second set of rings such that an equal number of rings of the third set of transducers are positioned on each side of the second set of rings.

11. The multi-way speaker array of claim 9 , wherein the third transducer is arranged on an end of the cylindrical cabinet and pointed in the direction of the center axis perpendicular to the first and second sets of transducers.

12. The multi-way speaker array of claim 11 , wherein the first set of first transducers are selected to produce audio frequencies in the first frequency range, the second set of second transducers are selected to produce audio frequencies in the second frequency range, and the third transducer is selected to produce audio frequencies in the third frequency range.

13. The multi-way speaker array of claim 12 ,
wherein the audio frequencies in the first frequency range of audio frequencies overlap with the audio frequencies in the second frequency range of audio frequencies; and
wherein the audio frequencies in the second frequency range of audio frequencies overlap with the audio frequencies in the third frequency range of audio frequencies.

14. The multi-way speaker array of claim 9 , wherein a center of each transducer in the first ring is aligned with a center of a trans

Assignees

• Apple Inc

Inventors

• Johnson Martin E
• Dix Gordon R
• Howes Michael B
• Geaves Gary P
• Saux Tom-Davy William Jendrik

Classifications

• H04R5/02

  Spatial or constructional arrangements of loudspeakers · CPC title

• H04R1/403 Primary

  loud-speakers · CPC title

• H04R2201/401

  2D or 3D arrays of transducers · CPC title