SOUND DIFFRACTION REDUCTION SPEAKER INCORPORATING META MATERIAL

Abstract

A speaker device incorporating acoustic meta materials for sound diffraction reduction wherein the meta materials have a plurality of channels to dampen sound waves. Meta materials are applied to the speaker unit, serve as structural components of a speaker baffle, waveguide, and/or cone. The meta materials have openings in them to permit sound waves to enter and positioned at the edges of the speaker cabinet to prevent sound waves from re-radiating and interfering with the sound waves intended for the listener.

Claims

1. A speaker having a cabinet with at least one driver having a cone secured within said cabinet, the improvement comprising: meta material having channels, said channels having entrances; said meta material fixed in a position in proximity to said cone of said at least one driver; said position being selected from the group of consisting of: an inner radius of said cone, an outer radius of said cone, an inner surface of said cone, or combination thereof; said entrances of said channels capable of receiving diffracted sound; and, whereby said diffracted sound from said speaker is dampened.

2. The speaker of claim 1, wherein said meta material is positioned at an inner radius of said cone and wherein said entrances of said channels are oriented anteriorly.

3. The speaker of claim 1, wherein said meta material is positioned at an outer radius of said cone and wherein said entrances of said channels are oriented anteriorly.

4. The speaker of claim 1, wherein said meta material is positioned at an inner surface of said cone and wherein said entrances of said channels are oriented toward an interior volume of said cone.

5. The speaker of claim 1, wherein said cone is substantially flat and wherein said meta material is positioned on an inner surface of said cone such that said entrances of said channels are oriented anteriorly outward from said cabinet.

6. A speaker having a cabinet with at least one driver having a cone with a waveguide positioned in front of said driver in which said driver and waveguide are secured to said cabinet, the improvement comprising: meta material having channels, said channels having entrances; said meta material fixed in a position in proximity to said waveguide; said position being selected from the group of consisting of: a waveguide center, a waveguide perimeter, a waveguide surface, or combination thereof; said entrances of said channels capable of receiving diffracted sound; and, a. whereby said diffracted sound from said speaker is dampened.

7. The speaker of claim 5, wherein said meta material is positioned at an inner radius of said waveguide center and wherein said entrances of said channels are oriented anteriorly.

8. The speaker of claim 5, wherein said meta material is positioned at an outer radius of said waveguide perimeter and wherein said entrances of said channels are oriented anteriorly.

9. The speaker of claim 5, wherein said meta material is positioned at an inner surface of said waveguide surface and wherein said entrances of said channels are oriented toward an interior volume of said waveguide.

10. A speaker cone, comprising: a tapered conical sleave; a lesser internal radius at an end of said tapered conical sleave; a greater external radius opposite said lesser internal radius; and, meta material positioned about said tapered conical sleave, said meta material having a plurality of channel entrances.

11. The speaker cone of claim 9, wherein said channel entrances are oriented about said lesser internal radius and said channel entrances face anteriorly.

12. The speaker cone of claim 9, wherein said channel entrances are about said greater external radius and said channel entrances face anteriorly.

13. The speaker cone of claim 9, wherein said channel entrances are throughout said tapered conical sleave on an inner cone face and said channel entrances face toward the longitudinal axes of said tapered conical sleave.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0020] These and other features and advantages of the present invention will become appreciated, as the same becomes better understood with reference to the specification, claims and drawings herein:

[0021] FIG. 1 shows a sound diffraction reduction speaker with an external meta material plate array comprising channels and channel entrances.

[0022] FIG. 2 shows a sound diffraction reduction speaker, as shown in FIG. 1, where the sound diffraction reduction speaker is structurally composed of meta materials.

[0023] FIG. 3 shows a meta material plate fixed to a speaker baffle for use in a sound diffraction reduction speaker, as shown in FIG. 1.

[0024] FIG. 3A shows a baffled-fixed meta material plate as shown in FIG. 3 where the meta material channel entrances are located at the baffle plate inner ring.

[0025] FIG. 3B shows baffled-fixed meta material plate as shown in FIG. 3 where the meta material channel entrances are located at the baffle plate outer perimeter.

[0026] FIG. 3C shows a baffled-fixed meta material plate as shown in FIG. 3 where the meta material channel entrances are located across the outer surface of the meta material plate.

[0027] FIG. 4 shows a meta material array configured into a wave guide for use in a sound diffraction reduction speaker, as shown in FIG. 1.

[0028] FIG. 4A shows a meta material waveguide as shown in FIG. 4 where the meta material channel entrances are about the waveguide center.

[0029] FIG. 4B shows a meta material waveguide as shown in FIG. 4 where the meta material channel entrances are about the waveguide perimeter.

[0030] FIG. 4C shows a meta material waveguide as shown in FIG. 4 where the meta material channel entrances are about the surface.

[0031] FIG. 5 shows a speaker cone comprised of meta materials for use in a sound diffraction reduction speaker, as shown in FIG. 1.

[0032] FIG. 5A shows a meta material speaker cone where the metal material channel entrances are located about the inner radius of the driver cone.

[0033] FIG. 5B shows a meta material speaker cone where the metal material channel entrances are located about the outer radius of the driver cone.

[0034] FIG. 5C shows a meta material speaker cone where the metal material channel entrances are located about the inner surface of the driver cone.

DETAILED DESCRIPTION OF THE INVENTION

[0035] The invention now will be described more fully hereinafter with reference to the accompanying drawings, in which embodiments of the invention are shown. This invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art.

[0036] It will be understood that when an element is referred to as being “on” another element, it can be directly on the other element or intervening elements may be present there between. As used herein, the term “and/or” includes any and all combinations of one or more of the associated listed items.

[0037] It will be understood that, although the terms first, second, third etc. may be used herein to describe various elements, components, regions, layers and/or sections, these elements, components, regions, layers and/or sections should not be limited by these terms. These terms are only used to distinguish one element, component, region, layer or section from another element, component, region, layer or section.

[0038] As used herein, the singular forms “a,” “an,” and “the,” are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms “comprises” and/or “comprising,” “includes” and/or “including,” and “have” and/or “having,” when used in this specification, specify the presence of stated features, regions, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, regions, integers, steps, operations, elements, components, and/or groups thereof.

[0039] Furthermore, relative terms, such as “lower” or “bottom,” and “upper” or “top,” and “inner” or “outer,” may be used herein to describe one element's relationship to another elements as illustrated in the Figures. It will be understood that relative terms are intended to encompass different orientations of the device in addition to the orientation depicted in the Figures.

[0040] Unless otherwise defined, all terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. It will be further understood that terms, such as those defined in commonly used dictionaries, should be interpreted as having a meaning that is consistent with their meaning in the context of the relevant art and the present disclosure, and will not be interpreted in an idealized or overly formal sense unless expressly so defined herein.

[0041] Exemplary embodiments of the present invention are described herein with reference to idealized embodiments of the present invention. As such, variations from the shapes of the illustrations as a result, for example, of manufacturing techniques and/or tolerances, are to be expected. Thus, embodiments of the present invention should not be construed as limited to the particular shapes of regions illustrated herein but are to include deviations in shapes that result, for example, from manufacturing.

[0042] As shown in FIG. 1, meta materials 1 are comprised of a collection of maze-like meta material channels 3. The meta material channels 3 are open at one end and closed at the other. The opening serves to allow for sound wave entry. The meta material channels 3 are of varying lengths. The meta material channels 3 are at least long enough that each meta material channel 3 may serve as a ¼ wave resonant absorber. Sufficient length determination is a function of the building materials used and sound wave volume as mathematically modeled by an expert in the field. Each discrete meta-material channel 3 length provides for efficient sound absorption over a corresponding narrow wave band. By stacking a plurality of these different length channels together as an array and into a plate, the meta material channels 3 can be made to stagger the resonant frequencies absorbed so as to act together as a wideband absorber. In this way their absorption efficiency can exceed 95%. The meta material channels 3 have meta material channel entrances 5 into which sound waves may enter. The meta material channel entrances 5 may be located at an anterior edge 12 of a meta material plate 7, or across its surface, as shown in FIG. 1. The meta material plates 7 serve as a discrete unit of meta material 1. Meta materials 1 and meta material plates 7 are affixed to structural surfaces with adhesive or other suitable attachment means. The adhesive may be of any type suitable for use with speakers.

[0043] Diffraction occurs at the perimeter of the cabinet 9 of the speaker 2, which is a structural casing for embodiments of the present invention. As shown in FIG. 1, a first embodiment of the invention places a plurality of meta material plates 7 at outer faces of the cabinet 9. The meta material plates 7 are mounted to the external surfaces of the top, bottom, and sides of the cabinet 9 as shown in FIG. 1. These external surfaces intersect the anterior cabinet face 10. The meta material channel entrances 5 are at the anterior edge 12 of the meta material plates 7. This placement is such that where drivers propel sound waves out through an anterior cabinet face 10, sound waves enter the meta material channels 5 rather than detrimentally diffracting. In this orientation, as the sound wave reaches the edge of the speaker cabinet 9, the waves are almost fully absorbed by the meta material 1, thereby preventing sound from re-radiating.

[0044] In a second embodiment, the speaker cabinet 7 itself is constructed from the meta materials 1 as shown in FIG. 2. In this embodiment the meta material channel entrances 5 may open along the outer surface 8 of the meta material plate 7. In other embodiments the meta material channel entrances 5 may open along an inner surface 6 which is opposite the outer surface 8, along the anterior edges 12, or in an optimal orientation, any combination of these. The meta material channel entrances 5 absorb both diffracted sound from a baffle 11 or absorb sound inside the speaker cabinet 9.

[0045] In a third embodiment, a meta material plate 7 is mounted onto a baffle front surface 14 as shown in FIG. 3. The baffle 11 allows sound to radiate from the tweeter 15. The meta material plate 7 mounted on the baffle 11 has three meta material channel entrance 5 locations as shown, but can be any number that is appropriate for the size of the baffle 11. The meta material channel entrance 5 may be either at the baffle plate inner ring 19 as shown in FIG. 3A, the baffle plate outer perimeter 21 as shown in FIG. 3B, spread across the baffle plate surface 23 as shown in FIG. 3C, or any combination of these. In this embodiment the optimal meta material channel entrance 5 orientation is to face anteriorly.

[0046] In a fourth embodiment, the meta material 1 can be built into the shape of a waveguide 25 as shown in FIG. 4. The waveguide 25 meta material 5 may be either at the waveguide center 27 as shown in FIG. 4A, at the waveguide perimeter 29 as shown in FIG. 4B, or across the waveguide surface 31 as shown in FIG. 4C, depending upon design performance requirements. In this embodiment, the optimal orientation for the meta material channel entrance 5 is facing anteriorly for meta material placed at the waveguide center 27 and for meta material placed at the waveguide perimeter 29. The optimal orientation for the meta material channel entrance for meta material placed on the waveguide surface 31 is facing the interior volume of the wave guide 48.

[0047] In a fifth embodiment, the meta material 1 is the structural component of a driver cone 37 as shown in FIG. 5. In a preferred embodiment, the driver cone is the woofer cone 37. In this embodiment, the meta material 5 can be mounted within the woofer cone 35 as shown in FIG. 5 at three locations. The meta material 5 may be at a driver cone inner radius 39 as shown in FIG. 5A, a driver cone outer radius 41 as shown in FIG. 5B, or spread across a driver cone inner surface 43 as shown in FIG. 5C, or any combination thereof. The outer surface 51 of the cone faces the interior of the cabinet 9. In FIGS. 5B and 5C, only the cone 35 is shown. One skilled in the art would understand that the other components of the driver to convert electrical energy into acoustical energy are secured to the apex or narrowest point of the cone.

[0048] Alternatively, the meta material 5 is positioned on the woofer cone inner surface 43 and can blanket the entire surface. The meta material channel entrances 5 are oriented anteriorly when positioned at the apex of the woofer cone and when positioned at the outer radius of the cone. The meta material channel entrances 5 are oriented toward the interior volume 45 of the cone 37 when the metal material is positioned on the inner surface 43 of the cone 37.

[0049] In another embodiment, speaker cone 37 comprises a tapered conical sleave 49, a lesser internal radius 39 at an end of said tapered conical sleave 49, a greater external radius 41 opposite said lesser internal radius 39; and, meta material 1 positioned about said tapered conical sleave 49, said meta material 1 having a plurality of channel entrances 5. The channel entrances 5 can be oriented about said lesser internal radius 39 and said channel entrances 5 face anteriorly or the channel entrances 5 can be about said greater external radius 41 and said channel entrances 5 face anteriorly. Or the channel entrances 5 can be throughout said tapered conical sleave 49 facing the interior volume 45 and said channel entrances 5 face toward the longitudinal axes of said tapered conical sleave 49.