Front port resonator for a speaker assembly

Patent metadata

Field	Value
Publication number	US-10299032-B2
Application number	US-201715701335-A
Country	US
Kind code	B2
Filing date	Sep 11, 2017
Priority date	Sep 11, 2017
Publication date	May 21, 2019
Grant date	May 21, 2019

Abstract

A micro-speaker assembly including an enclosure having an enclosure wall separating a surrounding environment from an encased space, wherein the enclosure wall defines an acoustic port from the encased space to the surrounding environment; a sound radiating surface positioned within the encased space and dividing the encased space into a front volume chamber and a back volume chamber, wherein the front volume chamber is acoustically coupled to a first surface of the sound radiating surface and the acoustic port, and the back volume chamber acoustically coupled to a second surface of the sound radiating surface; and a resonator acoustically coupled to the front volume chamber, wherein the resonator comprises a neck acoustically coupled to an acoustic cavity, and an opening to the neck is positioned at a distance from the acoustic port that corresponds to a quarter wavelength resonance of the front volume chamber.

First claim

What is claimed is:

1. A micro speaker assembly comprising:
an enclosure having an enclosure wall separating a surrounding environment from an encased space, wherein the enclosure wall defines an acoustic port from the encased space to the surrounding environment;
a sound radiating surface positioned within the encased space and dividing the encased space into a front volume chamber and a back volume chamber, wherein the front volume chamber is acoustically coupled to a first surface of the sound radiating surface and the acoustic port, and the back volume chamber acoustically coupled to a second surface of the sound radiating surface;
a resonator acoustically coupled to the front volume chamber, wherein the resonator and the acoustic port are positioned along different sides of the sound radiating surface, and the resonator comprises a neck acoustically coupled to a closed acoustic cavity, and an opening to the neck is positioned at a distance from the acoustic port that corresponds to a quarter wavelength resonance of the front volume chamber;
a voice coil extending from the second surface of the sound radiating surface; and
a magnet assembly having a magnetic gap aligned with the voice coil.

2. The micro speaker assembly of claim 1 wherein the distance from the acoustic port that corresponds to the quarter wavelength resonance is greater than a distance from the acoustic port to a center axis of the sound radiating surface, and the resonator is on a different side of the center axis than the acoustic port.

3. The micro speaker assembly of claim 1 wherein the resonator is tuned to resonate at a same frequency as a quarter wave resonance of the front volume chamber such that it extends a frequency bandwidth of a sound generated by the sound radiating surface.

4. The micro speaker assembly of claim 1 wherein the neck of the resonator comprises a narrower cross-section than the closed acoustic cavity.

5. The micro speaker assembly of claim 1 wherein the opening to the neck of the resonator faces a different direction than the acoustic port.

6. The micro speaker assembly of claim 1 wherein the neck of the resonator defines a tortuous acoustic pathway.

7. The micro speaker assembly of claim 1 wherein the closed acoustic cavity defines a tortuous acoustic pathway.

8. The micro speaker assembly of claim 1 wherein the resonator is positioned within the enclosure and the closed acoustic cavity occupies a portion of the back volume chamber within the encased space.

9. The micro speaker assembly of claim 1 wherein the closed acoustic cavity is acoustically isolated from the back volume chamber.

10. The micro speaker assembly of claim 1 wherein the enclosure wall comprises a top wall that is parallel to a bottom wall, and a side wall connecting the top wall to the bottom wall, and wherein the resonator is formed in part by at least one of the top wall, the bottom wall of the side wall.

11. The micro speaker assembly of claim 1 wherein the enclosure wall comprises a top wall that is parallel to a bottom wall, and a side wall connecting the top wall to the bottom wall, and wherein the acoustic port is positioned within the side wall.

12. A micro speaker assembly comprising:
an enclosure having an enclosure wall separating a surrounding environment from an encased space, wherein the enclosure wall defines an acoustic port from the encased space to the surrounding environment;
a sound radiating surface positioned within the encased space and dividing the encased space into a front volume chamber acoustically coupled to a first surface of the sound radiating surface and a back volume chamber acoustically coupled to a second surface of the sound radiating surface, and wherein the front volume chamber is acoustically coupled to the acoustic port;
a Helmholtz resonator acoustically coupled to the front volume chamber and the acoustic port, and wherein a closed cavity of the Helmholtz resonator is positioned within the back volume chamber and is not acoustically coupled to the back volume chamber;
a voice coil extending from the second surface of the sound radiating surface; and
a magnet assembly having a magnetic gap aligned with the voice coil.

13. The micro speaker assembly of claim 12 wherein the Helmholtz resonator is operable to extend a frequency bandwidth of a sound generated by the sound radiating surface in comparison to a micro speaker assembly without a Helmholtz resonator.

14. The micro speaker assembly of claim 12 wherein the Helmholtz resonator is tuned to resonate at a same frequency as a quarter wave resonance of the front volume chamber.

15. The micro speaker assembly of claim 12 wherein an opening to the Helmholtz resonator is positioned at a pressure maximum of a quarter wave resonance of the front volume chamber.

16. The micro speaker assembly of claim 12 wherein the Helmholtz resonator is acoustically coupled to the front volume chamber at a location that is farther from the acoustic port than a center axis of the sound radiating surface.

17. The micro speaker assembly of claim 12 wherein the Helmholtz resonator comprises an interior damping member that forms a tortuous acoustic pathway within the Helmholtz resonator.

18. The micro speaker assembly of claim 12 wherein a perimeter of the sound radiating surface is defined by four sides, and the Helmholtz resonator is positioned along a side of the sound radiating surface that is different than the acoustic port.

19. An electroacoustic transducer assembly comprising:
an enclosure separating a surrounding environment from an encased space, wherein the enclosure comprises a top wall, a bottom wall and a side wall connecting the top wall to the bottom wall, and an acoustic port formed within the side wall and connecting the encased space to the surrounding environment;
a driver positioned within the encased space, the driver comprising a sound radiating surface dividing the encased space into a front volume chamber and a back volume chamber, wherein the front volume chamber is acoustically coupled to the acoustic port and defined in part by the top wall and a first surface of the sound radiating surface that faces the top wall, and the back volume chamber is defined in part by the bottom wall and a second surface of the sound radiating surface; and
a resonator acoustically coupled to the front volume chamber, wherein the resonator comprises an acoustic channel having one end open to the front volume chamber and another end open to a closed acoustic cavity, and wherein the closed acoustic cavity is positioned within the back volume chamber.

20. The electroacoustic transducer assembly of claim 19 wherein the one end of the acoustic channel is open to the front volume chamber at a location that is a distance from the acoustic port that corresponds to a quarter wavelength resonance of the front volume chamber, the only acoustic pathway to the closed acoustic cavity is through the another open end of the acoustic channel, and the closed acoustic cavity is positioned between the second surface of the sound radiating surface and the bottom wall.

Assignees

• Apple Inc

Inventors

• Grazian Anthony P
• Wilk Christopher
• Notarangelo Claudio
• Tao Hongdan
• Newman Michael J
• Ilkorur Onur I
• Tsang Thomas H

Classifications

• H04R9/06

  Loudspeakers · CPC title

• H04R2201/003

  Mems transducers or their use · CPC title

• H04R1/2811 Primary

  for loudspeaker transducers · CPC title

• H04R1/021

  incorporating only one transducer · CPC title

• H04R2499/15

  Transducers incorporated in visual displaying devices, e.g. televisions, computer displays, laptops · CPC title