HK1146344A - Method and apparatus for loudspeaker assembly - Google Patents

Abstract

A method and apparatus for providing a loudspeaker assembly is provided. In accordance with at least one embodiment, a method is provided for mounting a loudspeaker driver in a loudspeaker driver aperture defined in a ground plane and installing a grille in relation to the ground plane such that a distance between the grille and the ground plane decreases as the distance from the loudspeaker driver increases. In accordance with at least one embodiment, apparatus is provided comprising a ground plane, a loudspeaker driver mounted in a loudspeaker driver aperture of the ground plane, and a grille positioned relative to the ground plane such that a distance between the grille and the ground plane decreases with increasing distance from the loudspeaker driver.

Description

Method and apparatus for a loudspeaker assembly

Cross Reference to Related Applications

This patent application is a continuation-in-part application of U.S. patent application No. 12/163,929, filed on 27/6/2008, and is hereby incorporated by reference in its entirety.

Technical Field

At least one embodiment of the invention relates generally to a method and apparatus for a loudspeaker assembly and, more particularly, to an apparatus and method that may be mounted on or in a surface, such as a ceiling.

Background

Because the speaker is a transducer that converts electrical energy into mechanical energy, the speaker assembly is typically designed to meet physical constraints, including electrical and mechanical constraints. The degree to which these limits are met can affect the acoustic performance of the speaker assembly. When the speaker assembly is installed in a surface, such as a ceiling, it is preferable for the installed speaker assembly to maintain the desired properties of the surface, such as strength, fire resistance, seismic stability, and aesthetics.

U.S. patent No. 6,944,312 issued to Mason et al discloses a lightweight, fully assembled speaker enclosure including a rear baffle having a peripheral edge, a grill that is crimped or bent around the peripheral edge of the rear baffle, and a sound-reflecting sheet disposed between the rear baffle and the grill, the sound-reflecting sheet having an opening in which a speaker is placed. The acoustic reflector is preferably formed of vinyl or thin polyester film and is said to block or inhibit sound waves from re-entering the speaker.

U.S. patent No. 7,120,269 to Lowell et al discloses a tile-embedded system for supporting speakers in new or existing suspended ceilings, further represented as including a perforated base portion that provides maximum free air space. The system has a plate providing a solid surface for mounting one or more speakers, with a rear cabinet optionally mounted over the speakers and secured with nuts.

Prior art systems do not address meeting physical constraints including defining a three-dimensional speaker frame structure and providing enhanced acoustic impedance matching while also maintaining desired properties such as strength, fire resistance, seismic stability, and aesthetics.

Furthermore, the sound field patterns provided by prior art systems are not ideal or good. Sound pressure levels vary greatly at different locations relative to the speaker system, which has resulted in different perceived sound intensities for listeners at different locations relative to the speaker system and for listeners moving relative to the speaker system. Accordingly, there is a need for a method and apparatus for providing a speaker assembly that avoids the disadvantages of the prior art.

Disclosure of Invention

The invention provides a method and apparatus for providing a speaker assembly. In accordance with at least one embodiment, a method is provided for mounting a speaker driver in a speaker driver aperture defined in a ground plane and mounting a grille relative to the ground plane such that a distance between the grille and the ground plane is a function of a distance from the speaker driver. In various embodiments, the distance between the grille and the ground plane increases, remains the same, decreases, or varies according to a more complex function as the distance from the speaker driver increases. This results in a change of the sound distribution pattern. According to at least one embodiment, there is provided an apparatus comprising a ground plane, a speaker driver mounted in a speaker driver aperture of the ground plane, and a grille disposed relative to the ground plane such that a distance between the grille and the ground plane decreases with increasing distance from the speaker driver.

Drawings

The present invention may be better understood, and its features made apparent to those skilled in the art by referencing the accompanying drawings.

FIGS. 1A and 1B are perspective views of a speaker frame assembly according to at least one embodiment;

FIG. 2 is a perspective view of a speaker assembly according to at least one embodiment;

FIG. 3 is a perspective view of a speaker assembly according to at least one embodiment;

FIG. 4 is a perspective view of a speaker frame subassembly according to at least one embodiment;

FIG. 5 is a cut-away perspective view of a speaker assembly according to at least one embodiment;

FIG. 6 is a flow diagram of a method for a speaker assembly according to at least one embodiment;

FIG. 7 is a cross-sectional view of a grille and ground plane of a speaker system in accordance with at least one embodiment;

FIG. 8 is a cross-sectional view of a grille and ground plane of a speaker system in accordance with at least one embodiment;

FIG. 9 is a cross-sectional view of a grille and ground plane of a speaker system according to at least one embodiment;

FIG. 10 is a cross-sectional view of a grille and ground plane of a speaker system according to at least one embodiment;

FIG. 11 is a cross-sectional view of a grille and ground plane of a speaker system according to at least one embodiment;

FIG. 12 is a cross-sectional view of a grille and ground plane of a speaker system according to at least one embodiment;

FIG. 13 is a cross-sectional view of a grille and ground plane of a speaker system according to at least one embodiment;

fig. 14 is a flow diagram illustrating a method for mounting a grille and a ground plane of a speaker system in accordance with at least one embodiment.

Like reference symbols in the various drawings indicate like elements.

Detailed Description

The invention provides a method and apparatus for providing a speaker assembly. In accordance with at least one embodiment, a method is provided that includes forming a speaker frame so as to define a driver housing portion, a horn portion, and a conformal portion. An actuator aperture defining an actuator housing portion, a port hole defining a horn portion. The driver is connected to the speaker frame proximate the driver aperture. The ground plane is connected to the speaker frame proximate the driver aperture and the perimeter of the speaker frame. The rear sound insulating panel is applied to a first conformal portion surface of the conformal portion of the speaker frame. The rear sound insulation board defines a horn cavity wall of a horn cavity of the horn portion. The horn cavity has a cross-sectional area that increases with increasing distance from the driver housing portion. The grille is applied to a second conformal portion surface of the conformal portion of the speaker frame. The application of the grille, which joins the speaker frame to the rear sound insulating panel, can be achieved by crimping the peripheral edge of the grille to the rear sound insulating panel.

In accordance with at least one embodiment, the rear acoustic panel further defines a driver cavity wall of the driver cavity of the driver housing portion. The first conformal portion surface of the conformal portion substantially conforms to a first rear baffle surface of the rear baffle. The grille can be applied such that a first grille portion of the grille is adjacent the driver aperture and a second grille portion of the grille is adjacent the port aperture, the first grille portion being substantially coplanar with the second grille portion.

According to at least one embodiment, the rear baffle is formed of a material such that the rear baffle defines a horn chamber wall that may be covered with a porous or non-porous skin. For example, in one or more embodiments, the rear sound insulating panel may be formed from a flame retardant pressed glass fiber or mineral fiber material having a non-porous aluminum skin. The grille may be applied to the generally planar peripheral portion of the speaker frame such that the generally planar peripheral portion surrounds the elevated portion of the speaker frame. The elevated portion of the speaker frame surrounds the driver housing portion and the horn portion. In accordance with at least one embodiment, the generally planar peripheral portion of the speaker frame lies substantially in a first plane and the elevated portion of the speaker frame lies substantially in a second plane, wherein the first plane is substantially parallel to the second plane.

According to at least one embodiment, there is provided an apparatus comprising a speaker frame, a driver, a rear sound insulating panel, and a grille. The speaker frame defines a driver housing portion, a horn portion, and a conformal portion. The driver housing portion defines a driver orifice and the horn portion defines a port hole. The driver is adjacent to the speaker frame proximate to the driver aperture. The rear sound insulating panel has a first rear sound insulating panel surface. The first conformal portion surface of the conformal portion of the speaker frame substantially conforms to the first rear baffle surface. The first rear baffle plate surface defines a horn chamber wall of a horn chamber of the horn section. The horn cavity has a cross-sectional area that increases with increasing distance from the driver housing portion. The grille is adjacent to a second conformal portion surface of the conformal portion of the speaker frame. The grill couples the speaker frame to the rear sound insulating panel.

In accordance with at least one embodiment, the rear acoustic panel further defines a driver cavity wall of the driver cavity of the driver housing portion. The first conformal portion surface of the conformal portion substantially conforms to a first rear baffle surface of the rear baffle. The grill includes a first grill portion adjacent the driver aperture and a second grill portion adjacent the port aperture. The first grill portion is substantially coplanar with the second grill portion. The rear baffle plate is formed of a material such that the rear baffle plate defines a horn chamber wall. The material may include a non-porous skin, such as aluminum.

In accordance with at least one embodiment, the speaker frame further comprises a substantially planar peripheral portion and a raised portion. A generally planar peripheral portion surrounds the elevated portion. The elevated portion surrounds the driver housing portion and the horn portion.

In accordance with at least one embodiment, the generally planar peripheral portion of the speaker frame lies substantially in a first plane and the elevated portion of the speaker frame lies substantially in a second plane. The first plane is substantially parallel to the second plane.

In accordance with at least one embodiment, a three-dimensionally shaped plate defines a driver housing portion, a horn portion, a generally planar peripheral portion, and a raised portion. The driver housing portion defines a driver aperture. The actuator housing portion communicates with the narrow end of the horn portion. The cross-sectional area of the horn portion increases with distance from the driver housing portion. According to at least one embodiment, the three-dimensionally shaped panel is a vacuum-formed panel. According to at least one embodiment, the three-dimensionally shaped plate is an injection molded plate. According to at least one embodiment, the three-dimensionally shaped plate is a cast plate. According to at least one embodiment, the three-dimensionally shaped panel is a pressed panel.

According to at least one embodiment, the substantially planar portion surrounds the elevated portion. The elevated portion substantially surrounds the driver housing portion and the horn portion. The substantially planar portion lies substantially within the first plane. The elevated portion lies substantially in a second plane. The first plane is substantially parallel to the second plane.

In accordance with at least one embodiment, the horn portion defines a port aperture remote from the driver housing portion. The vacuum-formed panel also defines an electrical terminal housing for receiving the electrical terminal. The port bore cross-sectional area of the port bore is greater than the driver orifice cross-sectional area of the driver orifice.

Fig. 1A and 1B are perspective views of a speaker frame subassembly according to at least one embodiment. For clarity, fig. 1A shows the situation without the ground plane 112, while fig. 1B shows the speaker frame subassembly including the ground plane 112 in the complete situation. The speaker frame subassembly 101 includes a speaker frame 102, a ground plane 112, and a driver 103. The speaker frame 102 defines a driver aperture 104. The ground plane 112 defines a similar aperture adjacent the aperture 104. The driver 103 is connected to the speaker frame 102 and the ground plane 112 via fasteners 105, the fasteners 105 fastening the driver 103 to the speaker frame proximate the driver aperture 104. The fastener 105 is preferably disposed about the driver aperture 104. Although the term "ground plane" is used, the ground plane 112 may not be planar and not parallel to any particular surface in accordance with at least one embodiment. Instead, the ground plane 112 is designed with a specific curvature or bend introduced during assembly to produce a favorable or desired frequency and Sound Pressure Level (SPL). In accordance with at least one embodiment, the ground plane 112 has a radius of curvature of about twenty feet at the center of the speaker aperture. In accordance with at least one embodiment, the ground plane 112 has a hyperbolic curvature or bend. According to at least one embodiment, the curvature or bend is concave, as shown in the perspective view in fig. 1 (e.g., by a grid placed in front of the elements shown in fig. 1). In other embodiments, the ground plane 112 may have a convex, planar, or other form such that the distance between the ground plane 112 and a grid placed in front of the elements shown in fig. 1 is a function of the distance from the axis of the driver 103. The function may be such that the distance increases, decreases, remains the same or varies in a more complex manner, which results in a variation in the way the sound is spread.

The speaker frame 102 is preferably vacuum formed to define a three-dimensional shape or profile of the driver housing portion 106 and the horn portion 107. The driver housing portion 106 communicates with the horn portion 107 at the narrow end of the horn portion 107. As the horn portion 107 extends away from the driver housing portion 106, the cross-sectional area of the horn portion 107 increases. The rate of increase of the cross-sectional area may be linear, exponential or may follow a higher order function. The flared portion defines a port hole 108. The port hole 108 is disposed away from the driver housing portion 106. In one or more embodiments, the increased cross-sectional area of the horn portion 107 may provide improved acoustic impedance matching by acting as an acoustic transducer to provide a higher acoustic impedance at the narrow end of the horn portion 107 near the driver 103 and a lower acoustic impedance at the wider end of the horn portion 107 away from the driver 103 and near the port hole 108. The increased cross-sectional area may also serve to cause a pressure reduction, causing the effect of "pulling or pumping" or vacuum of the accelerated sound waves towards the port. The acoustic impedance transformation provided by the horn portion 107 allows for a small offset or displacement at the driver 103 to move a larger volume of air at the port hole 108, thereby increasing the efficiency of the speaker assembly. This allows the port hole size to be larger than conventional open-ported or open-ended speakers. The effect of this is that small drivers (e.g., three inch drivers) are now used as larger drivers (e.g., six inch drivers) because the driver size effectively becomes the sum of the area of the driver and the area of the incorporated port. A larger port means that the speaker acts as if it had a larger mounted driver. The use of smaller drivers in conjunction with the horn is more efficient than other designs that use larger drivers without the horn section. By designing the driver smaller also a wider propagation or dispersion field is given, which avoids uneven projection of sound in the room. Thus, the ability to properly tune or tune the speakers results in a wider sound field, which allows one to cover an area of the same size with fewer speakers. Furthermore, the driver housing portion 106 and the horn portion 107 form a helmholtz resonator (helmholtz resonator) that can be tuned or adjusted to improve the frequency response of the speaker assembly.

According to at least one embodiment, the horn portion 107 has a cross-sectional area that substantially conforms to a quadratic function. According to at least one embodiment, the horn portion 107 has a shape that substantially conforms to a quadratic function y of 0.0234x²+0.3521x +1.1985 cross-sectional area. As an example, according to at least one embodiment, the cross-sectional area of the horn section 107 deviates from the quadratic function by no more than one percent. As another example, in accordance with at least one embodiment, the cross-sectional area of the horn section 107 deviates from the quadratic function by no more than one-half of a percent. As a further example, according to at least one embodiment, the cross-sectional area of the horn portion 107 deviates from the quadratic function by no more than 0.3 percent.

According to at least one embodiment, the port hole 108 has a port hole area substantially equal to a cross-sectional area of the flared portion 107 proximate to the port hole 108. The port aperture area of the port aperture 108 may be described in terms of a port effective radius, which represents the radius of a circle having the same area as the port aperture area of the port 108, as the port aperture 108 may be circular, but need not be circular.

According to at least one embodiment, the port hole 108 has a port effective radius that is mathematically related to the driver radius of the driven portion of the driver 103 (e.g., the speaker cone). According to at least one embodiment, the ratio of the port effective radius to the drive radius is approximately 1.1985. For example, for a driver 103 having a driver area of about 5.67266 square inches and a radius of about 1.34375 inches, the port hole area is about 8.148 square inches and the port effective radius is 1.61046 inches. According to at least one embodiment, the ratio of the port effective radius to the drive radius is between 1.15 and 1.25. According to at least one embodiment, the ratio of the port effective radius to the drive radius is between 1.1 and 1.3. According to at least one embodiment, the ratio of the port effective radius to the drive radius is between 1.0 and 1.4.

According to at least one embodiment, the driver aperture radius of the driver aperture 104 approximates the driver radius of the driven portion (e.g., speaker cone) of the driver 103. Thus, the mathematical relationship between the port effective radius and the actuator radius may also be applicable to the relationship between the port effective radius and the actuator orifice radius. Furthermore, the mathematical relationship between the port hole area of the port hole 108 and the actuator area of the actuated portion of the actuator 103 may also be applicable to the relationship between the port hole area and the actuator orifice area.

According to at least one embodiment, the specific dimensions of the horn portion 107, the driver housing portion 106, and the relationship therebetween, such as the cross-sectional area of the aperture defined between the horn portion 107 and the driver housing portion 106 to provide communication and propagation of the acoustic waves between the driver housing portion 106 and the horn portion 107, are determined as a function of the mechanical and/or electrical parameters of the driver 103. For example, these dimensions and relationships may be determined as a function of compliance or compliance (compliance) of the actuator 103. The compliance or compliance of the driver 103 may depend on, for example, the rigidity and/or elasticity of the spider and surround used to mount the speaker tray in the driver 103. As another example, these dimensions and relationships may be determined as a function of the Q factor (i.e., quality factor) of the driver 103. According to at least one embodiment, the dimensions and relationship of horn portion 107 and driver housing portion 106 are selected so as to substantially match the mechanical impedance of driver 103 to the mechanical impedance of free air present at port hole 108.

The speaker frame 102 also defines an electrical terminal housing 109. The electrical terminal housing 109 may serve as an outer housing for the electrical terminals of the speaker assembly. For example, the electrical terminals of the driver 103 may be mounted within the electrical terminal housing 109. Other electrical components may also be mounted within the electrical terminal housing 109. For example, an electrical transformer for providing compatibility to speaker systems that distribute 25 volts, 70.7 volts, or 100 volts may be mounted within electrical terminal housing 109. As another example, an amplifier may be mounted within electrical terminal housing 109 to make the speaker assembly a self-amplifying speaker assembly. As a further example, the volume control may be mounted within the electrical terminal housing 109. An adjustment aperture may be defined in the electrical terminal housing 109 to allow access to the volume control through the grille so that the volume may be easily adjusted after the speaker assembly has been mounted on a surface such as a ceiling. According to at least one embodiment, fasteners 113 (e.g., screws, rivets, snaps, etc.) are installed through holes defined in the electrical terminal housing 109 to connect the electrical terminal to the electrical terminal housing 109.

The speaker frame 102 also includes a conformal portion that includes a generally planar peripheral portion 111 and a raised portion 110. The conformal portion is adapted to conform or conform to the rear sound insulating panel. The rear sound insulating panel provides a driver chamber wall of a driver chamber defined by the driver housing portion and a horn chamber wall of a horn chamber defined by the horn portion. The rear sound insulating panel is preferably constructed as a mat of fire retardant material such as glass fibre or mineral wool and may be covered with a porous or non-porous skin such as aluminium. In one or more embodiments, the driver chamber walls and the horn chamber walls may reduce the Q of the helmholtz resonator formed by the driver housing portion and the horn portion, thereby reducing unwanted peaks and/or nulls in the frequency response of the speaker assembly.

The shape, size, and relationship of the driver and horn cavities may be designed to provide a desired frequency response of the speaker assembly. Because the speaker frame 102 can be formed with the freedom to define the desired driver and horn cavities, acoustic performance is not limited by the configuration of the rear and sound baffle plates. In contrast, by providing a driver housing portion and a horn portion for the driver and by defining a port hole for the driver, excellent acoustic performance can be obtained from a given rear baffle plate, even a low profile rear baffle plate. The relationship between the driver characteristics, the driver housing portion characteristics, the horn portion characteristics, and the size of the port hole can be designed to optimize the frequency response and efficiency of the speaker assembly. Preferably, the port holes are larger than the driver apertures, which improves speaker efficiency and acoustic response in terms of acoustic impedance conversion provided by the horn section.

Fig. 2 is a perspective view of a speaker assembly in accordance with at least one embodiment. The speaker assembly 203 includes a grill 201 and a rear sound insulating panel 202. A grill 201 and rear sound-insulating panel 202 surround the speaker frame and drivers. Preferably, the grille 201 is substantially planar and preferably has a pattern of apertures, and the aperture dimensions are selected for optimal acoustic transmission through the grille 201 to eliminate reflections in the speaker. The grill 201 includes a rim around its periphery, and the rim is preferably substantially flat. The rear sound insulating panel 202 includes a rim around its periphery, and the rim is preferably substantially flat. Preferably, with the edge around the periphery of the generally planar peripheral portion of the speaker frame disposed between the grille 201 and the edge around the periphery of the rear sound insulating panel 202, the edge around the periphery of the grille 201 is crimped or bent to the edge around the periphery of the rear sound insulating panel 202, which holds the speaker frame in a fixed position relative to the grille 201 and the rear sound insulating panel 202. The crimping or bending is also designed to provide a "pinch or crush" between the rear sound insulating panel 202 and the speaker frame 102, which provides a critical seal of the horn and speaker area. Any leakage or escape from the sides of the speaker will weaken the acoustic performance. Such leakage may be prevented or minimized by a critical seal. According to at least one embodiment, the grid 201 is rectangular or oblong. According to at least one embodiment, the grid 201 is square.

Fig. 3 is a perspective view of a speaker assembly in accordance with at least one embodiment. The rear sound insulating panel 202 of the speaker assembly 203 includes a generally planar peripheral portion 305 and a raised portion 306. The electrical terminal cover 301 is mounted on the elevated portion 306 with fasteners 304. The electrical terminal cover plate 301 includes a generally planar portion 307. Preferably, the fastener 304 is mounted on a generally planar portion 307. According to at least one embodiment, a wire aperture 303 through which the wire passes is defined in a recessed portion below the generally planar portion 307. The wiring may be connected to an electrical terminal mounted within the recess. Preferably, the generally planar peripheral portion 305 lies substantially in a first plane, and preferably, the elevated portion 306 lies substantially in a second plane, wherein the first plane is substantially parallel to the second plane.

Fig. 4 is a cut-away perspective view of a speaker frame subassembly in accordance with at least one embodiment. Fig. 4 shows the speaker frame subassembly without the rear sound insulating panel 202. The communication between the speaker driver housing portion 106 and the horn portion 107 can be seen. The wide end of the flared portion 107 is positioned such that the port hole 108 is proximate a portion of the grill 201. Because the port holes 108 provide communication between the interior of the rear sound insulating panel 202 and the grille 201, all of the interior of the rear sound insulating panel is not blocked or covered or shadowed by the grille 201. The inner edge of the grill 201 that defines the port aperture 108 is adjacent to the grill 201 and is nearly coplanar with the grill 201. A spacing may be provided between the horn section 107 and the grill 201 to reduce the risk of unwanted vibrations. Electrical terminals 401 are disposed in recessed portions below the electrical terminal cover 301 for connecting wires routed through the wire apertures 303 to circuitry and/or drivers 103 contained within the electrical terminal housing 109. By employing the electrical terminal 401 in the form of a terminal block rather than a wire nut, the possibility of vibration of the loosely contained wire nut striking the interior of the electrical terminal housing or the interior of the speaker box is avoided. Maintaining the polarity of the actuator 103 from the actuator 103 to the electrical terminal 401 marking its polarity allows proper electrical phasing to be maintained during the manufacturing process. The polarity is defined by color-coded wiring and polarity marks vacuum-formed into the speaker frame.

A stiffener 402 is defined within the speaker frame 102 and around a portion of the perimeter of the raised portion 110. According to at least one embodiment, the stiffener 402 is substantially semi-cylindrical in shape, terminating in a substantially semi-circular portion that the ground plane 112 presses or bears against. By forming the ground plane 112 from a material having a spring constant (e.g., metal), the ground plane 112 maintains a force between the ground plane and the speaker frame 102 against the spring bias of the stiffener 402 to suppress any resonant nodes that may cause vibrations or deformations that would adversely affect the frequency response of the speaker assembly. In accordance with at least one embodiment, a corrugated portion 403 is defined within the approximately cylindrical portion of the driver housing portion 106 to help maintain the spring biased relationship between the ground plane 112 and the speaker frame 102. In accordance with at least one embodiment, the ground plane 112 comprises a curved steel plate. In accordance with at least one embodiment, the ground plane 112 comprises a curved aluminum plate. In accordance with at least one embodiment, the ground plane 112 comprises a polymer plate. In accordance with at least one embodiment, the ground plane 112 comprises a composite plate.

Fig. 5 is a cut-away perspective view of a speaker assembly in accordance with at least one embodiment. As can be seen, the conformal portion of the speaker frame 102 including the generally planar peripheral portion 111 and the elevated portion 110 substantially conforms to the shape of the rear sound insulating panel 202 including the generally planar peripheral portion 305 and the elevated portion 306. The generally planar peripheral portion 111 is disposed adjacent, parallel to, and nearly coplanar with the planar peripheral portion 305. The elevated portion 110 is disposed adjacent, parallel to, and nearly coplanar with at least a portion of the elevated portion 306. Preferably, the edge around the perimeter of the grille 201 is bent or crimped around the generally planar perimeter portion 111 and the generally planar perimeter portion 305 to join the grille 201, speaker frame 102 and rear sound insulating panel 202 into a rigid, sealed assembly. Preferably, the bending or crimping of the grille 201 connects the grille 201 to the rear sound insulating panel 202 in a non-removable manner.

Because the conformal portion of the speaker frame 102 preferably substantially conforms to the shape of the rear sound insulating panel 202, the shape and size of the cavity defined in the speaker frame 102 can be precisely controlled. For example, the driver cavity defined by the driver housing portion 106 and a portion of the raised portion 306 of the rear sound insulating panel 202 provides a controlled volume around the driver 103. As another example, a horn cavity defined by the horn portion 107 and a portion of the raised portion 306 of the rear baffle 202 provides a controlled volume between the communication port connecting the driver housing portion 106 to the horn portion 107 and the port hole 108. Not only the volume or volume of the horn chamber can be controlled but also its shape can be controlled so as to form a horn with an increased cross-sectional area from the communication port to the port hole.

Although the components of the speaker assembly 203, such as the grill 201 and rear sound insulating panel 202, may be custom designed, the economics of mass production may improve the economic efficiency of the speaker assembly 203 if standard components are used. For example, a grille 201 and rear baffle 202 designed for heating, ventilation and cooling (HVAC) applications may be used to aesthetically match a standard ceiling, as it appears to match standard HVAC ceiling diffusers, and avoids the need to design and manufacture a grille 201 and rear baffle 202 specifically for a speaker assembly. Furthermore, testing and standard compliance or compliance can be simplified because typical HVAC grills and rear sound panels have been evaluated against standards such as light or fire, smoke, and mechanical testing (e.g., corrosion and impact, such as the UL181 standard). For example, HVAC grills and rear sound insulation panels identified as UL1480, E84, and/or UL181 compliant may be obtained. Compliance or compliance with such standards (e.g., UL2043) allows for the use of speakers in ambient air-conditioned spaces. Also, the HVAC grille may already incorporate features that provide standard compliance or compliance and improve safety, such as seismic drop off labels (sesimictie off tabs). Additionally, the HVAC grill may be formed from materials that have been subjected to and passed stringent performance tests with the desired performance. These tests include, for example, corrosion, humidity, and ultraviolet light exposure. By vacuum forming or injection molding the speaker frame 102 to facilitate the construction of a set or kit of speaker frame subassemblies 101 that may be enclosed within the grille 201 and rear soundboard 202, the speaker frame assembly 101 may be easily inserted between the grille 201 and rear soundboard 202 during assembly to produce a high performance speaker assembly, rather than just an HVAC grille and rear soundboard assembly. Holes may be cut in the rear acoustic panel 202 to accommodate the electrical terminal cover plate 301, and the electrical terminal cover plate 301 may be constructed of a material to maintain a standard compliance or compliance.

A speaker assembly adapted for installation in a surface such as a ceiling or wall provides additional utility and convenience if it can be easily installed with minimal adjustment to the surface. A convenient embedded speaker assembly may be provided by employing a lightweight material that conforms to regulatory standards and is shaped to conform to industry standard sizes and shapes (e.g., standard sizes for ceiling tiles). Existing ceiling tiles may be removed, wiring may be routed or routed to locations where the ceiling tiles have been removed, wiring may be connected to electrical terminals 401 that may be accessed from outside the speaker assembly, and the speaker assembly may be plugged into a drop ceiling to replace, in whole or in part, the removed ceiling tiles. Seismic dropout tags and/or grid dropout (grid tie-off) may be protected if appropriate. If necessary, a portion of the removed ceiling tile can be trimmed and replaced to complete the installation. By providing a volume control that is accessed through the grille 201, volume adjustments can be made after the speaker assembly has been mounted on a surface without requiring removal from the surface. According to at least one embodiment, the speaker assembly may be mounted on a drywall surface.

By providing a speaker frame 102 that has been formed (preferably vacuum formed) into a three-dimensional shape that defines features such as a horn section, the need for a two-dimensional baffle can be avoided. Thus, disadvantages associated with two-dimensional acoustical panels, such as vibration and sound distortion, can be avoided or minimized. By forgoing the board mounted directly to the grille, and instead mounting the speakers and related components in a three-dimensional speaker frame, at least one embodiment allows for the formation of a three-dimensional loaded horn design that greatly improves speaker efficiency and provides performance through a more efficient smaller driver (e.g., a three-inch driver) that previously required a much larger driver (e.g., a six-inch driver). This design also allows the driver and any plate to move away from the grill because contact between the driver or plate and the grill can cause vibration or distortion between the grill and the sound-damping sheet or plate in other speaker designs described above. This design may also allow for the installation of an arcuate, hyperbolic ground plane (e.g., a plane with a radius of curvature of about 20 feet at the center of the speaker aperture) around the speaker driver, sized and shaped to tailor the reproduced sound field and linearity of the sound or audio volume (e.g., pink noise). The curved ground plane may also help prevent or suppress unwanted rattling of the components of the speaker assembly by spring biasing against other components of the speaker assembly. This design may also provide a more robust, robust design, which results in easier installation and less shipping damage. The insulated rear sound insulation panel does not need to structurally support the speaker assembly because the speaker frame provides sufficient rigidity to structurally support the speaker assembly. While the insulated rear sound insulation panel may be used as a fire bag (fire wrap) to allow compliance with life safety standards, the insulated rear sound insulation panel also provides additional rigidity in critical areas to prevent or suppress resonant nodes of the speaker at specific frequencies. Accordingly, the insulated rear sound insulating panel is advantageous in ensuring a flat frequency response over a wide frequency range. The ground plane design may provide a near linear acoustic response for the speaker. Furthermore, depending on its structure, the ground plane may provide improved uniformity of acoustic dispersion throughout the listening area or range, preventing or suppressing "hot spots" or spikes (spikes) in the Sound Pressure Level (SPL) perceived as volume in a particular location under the speaker.

Because weight is a consideration for suspended embedded speaker assemblies, it is desirable to make such speaker assemblies as light as possible without sacrificing sound quality, adjusted compliance or compliance, mechanical stability, or aesthetics. Providing a speaker frame 102 shaped in a three-dimensional shape allows a more rigid speaker assembly to be constructed from a given type and thickness of material, or a speaker assembly to be constructed from a thinner and/or lighter material without sacrificing rigidity. Also, high strength, lightweight materials that provide an adjusted standard compliance or compliance may be used for grills and rear sound insulation panels in HVAC applications. HVAC rear sound insulation panels are typically formed from a mat of glass or mineral fibers, the outer surface (i.e., the raised surface) of which is covered with a metal foil material. To minimize weight, a lightweight foil material, such as aluminum foil, may be used. While standard HVAC rear sound insulation panels and grills may be used, the specific materials may be tailored to optimize the performance of the speaker assembly, if appropriate. According to at least one embodiment, the grille is a perforated metal plate with perforations of a size designed to optimize the acoustic response and eliminate reflections from the grille back into the speaker interior.

By forming the speaker frame 102 in three dimensions, the speaker frame 102 provides sufficient rigidity to mount the driver 103 to the speaker frame, thereby avoiding the need to mount the driver to the grill, which further improves the aesthetic appearance by avoiding mounting visible hardware, such as rivets, to the grill. By using the speaker frame 102 to mount the driver 103, vibration of the grill and deformation caused by such vibration can also be avoided or minimized. Furthermore, by not using the grid as a load bearing element, the chance of grid sagging (bagging) under the weight of the drive is reduced. Because the horn portion redirects and redirects acoustic energy from behind the driver 103 to a direction substantially parallel to the plane of the grille 201, the height of the speaker assembly above the grille can be minimized. In addition, the shaped speaker frame 102 allows the electrical terminal housing 109 to be recessed into the speaker frame and integrated with the speaker frame 102, which also facilitates reducing the overall profile of the speaker assembly. In addition, a low profile speaker with a shallower or shallower rear sound insulation panel may be provided. Such a low profile speaker assembly may be installed in situations where the installation does not have a higher profile speaker assembly. By employing a specially shaped speaker frame 102 with a small, efficient driver 103, at least one embodiment provides a low profile speaker assembly that can be mounted in a space with limited vertical headroom or clearance.

The three-dimensional form of the speaker frame 102 and its ability to define the horn portion 107 allows for smaller and lighter drivers 103 to be used with performance comparable to larger and heavier drivers. Even with smaller and lighter drivers 103, the horn section 107 provides an acoustic impedance transformation to allow the smaller surface area of the smaller and lighter drivers 103 to move the same amount of air as the larger surface area of the larger and heavier drivers can move. Thus, the risk of sagging of the grill 201 and vibrations and sound distortion is further reduced. Moreover, the ability to use a smaller and lighter driver 103 increases the economic efficiency of the speaker assembly.

Furthermore, the three-dimensional form of the speaker frame 102 and its ability to define the horn section 107 allows smaller and lighter drivers 103 to be used that are comparable to the performance of multiple drivers. For example, some speaker systems use multiple drivers to cover multiple frequency ranges. However, the acoustic impedance transformation provided by the horn portion 107 increases the acoustic impedance behind the driver 103, thereby helping the front of the driver 103 to radiate higher frequency spectral content efficiently, yet this also reduces the acoustic impedance at the port hole 108 to allow the lower frequency spectral content to be efficiently coupled to the room air in front of the port hole 108. Thus, horn section 107 effectively performs an acoustic crossover function, rather than electrically, thereby avoiding the need for large and bulky inductive and capacitive elements to form an electrical crossover network (cross network). Eliminating electrical crossovers also eliminates the phase shifts inherent in typical crossover networks. By implementing this acoustic crossover function with a lightweight speaker frame 102 defining a horn section 107, weight is reduced, risk of sagging is reduced, acoustic efficiency is improved, and economic efficiency is improved.

At least one embodiment may be used to provide a speaker assembly that is compatible with existing surfaces, such as existing ceiling tiles. For example, a 1x2 speaker assembly may be used to replace half of a standard 2x2 ceiling tile or one quarter of a standard 2x4 ceiling tile. If higher volume and/or power handling capability is required, multiple speaker assemblies (e.g., multiple 1x2 speaker assemblies) may be bundled together with a filament and mounted one next to the other inside the space obtained by removing one or more ceiling tiles. Additional supports may be placed between the multiple speaker assemblies if desired.

Fig. 6 is a flow diagram of a method for a speaker assembly according to at least one embodiment. The method begins at step 601, where a speaker frame is formed to define a driver housing portion, a horn portion, and a conformal portion. The method continues with step 602, where an actuator aperture defining an actuator housing portion and a port hole defining a horn portion are defined. At step 603, the driver and ground plane are connected to the speaker frame adjacent the driver aperture. At step 604, a rear sound insulating panel ("back box") is applied to a first conformal portion surface of the conformal portion of the speaker frame. The rear sound insulation board defines a horn cavity wall of a horn cavity of the horn portion. The horn cavity has a cross-sectional area that increases with increasing distance from the driver housing portion. At step 605, a grille is applied to a second conformal portion surface of the conformal portion of the speaker frame. A grill is applied to join the speaker frame to the rear sound insulating panel.

In accordance with at least one embodiment, the rear acoustic panel also defines a driver cavity wall of the driver cavity of the driver housing portion. In accordance with at least one embodiment, the first conformal portion surface of the conformal portion substantially conforms to the first rear baffle surface of the rear baffle.

According to at least one embodiment, step 605 further comprises step 606. In step 606, the grille is bent or crimped to the rear sound insulating panel. According to at least one embodiment, step 605 further includes step 607. At step 607, a grill is applied or applied such that a first grill portion of the grill is adjacent the driver aperture and a second grill portion of the grill is adjacent the port aperture. The first grill portion is substantially coplanar with the second grill portion. According to at least one embodiment, the rear sound insulating panel is formed from a porous material such that the rear sound insulating panel defines the horn chamber wall as a porous horn chamber wall covered with a non-porous aluminum skin.

According to at least one embodiment, step 605 further comprises step 606. At step 606, a grille is applied to a generally planar perimeter portion of the speaker frame, wherein the generally planar perimeter portion surrounds a raised portion of the speaker frame that surrounds the driver housing portion and the horn portion. According to at least one embodiment, the substantially planar peripheral portion of the speaker frame lies substantially in a first plane and the elevated portion of the speaker frame lies substantially in a second plane, the first plane being substantially parallel to the second plane.

According to at least one embodiment, the flared portion 107 is defined along a substantially linear axis approximately in a radial direction of the driver housing portion 106. According to at least one embodiment, the horn portion 107 is defined along a substantially linear axis that is approximately tangential to the driver housing portion 106. According to at least one embodiment, the flared portion 107 is defined along a generally helical line extending outwardly from the driver housing portion 106. According to at least one embodiment, the flared portion 107 is defined along a line that curves in alternating directions as it progresses away from the driver housing portion 106.

According to at least one embodiment, the speaker frame 102 is vacuum formed from a polymer sheet into a three-dimensional structure. According to at least one embodiment, the speaker frame 102 is injection molded into a three-dimensional structure. According to at least one embodiment, the speaker frame 102 is cast into a three-dimensional structure. According to at least one embodiment, the speaker frame 102 is extruded as a three-dimensional structure.

When the speaker system is for providing sound to a listener moving relative to the speaker system or for providing sound to a plurality of listeners at different locations relative to the speaker system, it is advantageous to provide a degree of control over the overall directionality of the sound provided by the speaker system. According to at least one embodiment, variations in sound pressure levels provided to multiple listeners in different locations and listeners moving relative to the speaker system location may be reduced. According to at least one embodiment, the ground plane defines a speaker driver aperture in which the speaker driver is mounted, and the perforated grille is mounted such that a distance between the perforated grille and the ground plane is a desired function of a distance from the speaker driver. In one or more embodiments, the function is such that the distance between the grating and the ground plane decreases with distance from the driver. Such a configuration may be used to reduce sound pressure level variations over a large area and over a wide angular range of listener positions relative to the speaker system. The angle relative to the speaker system may be measured relative to an axis of the speaker driver, an axis of the ground plane, a line perpendicular to the ground plane through the speaker driver, an axis of the grille, and/or a line perpendicular to the grille through the speaker driver.

Fig. 7 is a cross-sectional view of a grille and ground plane of a speaker system in accordance with at least one embodiment. The device comprises a driver 701, a ground plane 702 and a grid 703. The driver 701 is mounted in an aperture defined in the ground plane 702. The ground plane 702 is concavely curved with respect to the grating 703, whereas the grating 703 is substantially flat. Thus, the distance between ground plane 702 and grid 703 decreases with increasing distance from driver 701. The grid 703 is perforated. According to at least one embodiment, the perforations of the grid 703 are regular and circular.

In one or more embodiments, the drivers 701, ground plane 702, and perforated grid 703 interact or interact to reduce the variation of the sound field over a large area. For example, in one or more embodiments, if the device is mounted on a ceiling, the device may reduce variations in Sound Pressure Level (SPL) of the sound of a listener up to within about seven meters of the device. If such a listener moves around within this range, not only does the distance of the listener's ears from the device change, but the angle between the axis of the driver 701 and the listener's ears also changes. For example, if the listener's ears are approximately two meters from the floor, and the ceiling speaker according to at least one embodiment of the apparatus is approximately 2.7 meters from the floor, the distance of the listener's ears from the speaker varies from about 0.7 meters to about 7 meters, or a 10: 1 ratio, and the angle between the listener's ears and the axis of driver 701 may vary from 0 degrees to about 85 degrees.

Fig. 8 is a cross-sectional view of a grille and ground plane of a speaker system in accordance with at least one embodiment. The device includes a driver 801, a ground plane 802, and a grid 803. Driver 801 is mounted in an aperture defined in ground plane 802. Ground plane 802 is nearly flat with respect to grating 803, while grating 803 is concavely curved toward ground plane 802. Thus, the distance between ground plane 802 and grating 803 decreases with increasing distance from driver 801. The grid 803 is perforated. According to at least one embodiment, the perforations of grid 803 are regular and circular.

Fig. 9 is a cross-sectional view of a grille and ground plane of a speaker system in accordance with at least one embodiment. The device comprises a driver 901, a ground plane 902 and a grid 903. The driver 901 is mounted in an aperture defined in the ground plane 902. Ground plane 902 is convexly curved toward grating 903, and grating 903 is concavely curved toward ground plane 902 with a radius of curvature substantially smaller than that of ground plane 902. Thus, the distance between ground plane 902 and grid 903 decreases with increasing distance from driver 901. The grid 903 is perforated. According to at least one embodiment, the perforations of the grid 903 are regular and circular.

Fig. 10 is a cross-sectional view of a grille and ground plane of a speaker system in accordance with at least one embodiment. The device comprises a driver 1001, a ground plane 1002 and a grid 1003. The driver 1001 is mounted in a hole defined in the ground plane 1002. Ground plane 1002 is curved concavely with respect to grid 1003, while grid 1003 is curved convexly with respect to ground plane 1002 with a radius of curvature substantially greater than that of ground plane 1002. Therefore, the distance between the ground plane 1002 and the grid 1003 decreases as the distance from the driver 1001 increases. The grid 1003 is perforated. According to at least one embodiment, the perforations of grid 1003 are regular and circular.

Fig. 11 is a cross-sectional view of a grille and ground plane of a speaker system in accordance with at least one embodiment. The device includes a driver 1101, a ground plane 1102, and a grid 1103. Driver 1101 is mounted in an aperture defined in ground plane 1102. The ground plane 1102 is convexly curved with respect to the grating 1103, while the grating 1103 is substantially flat. Thus, the distance between the ground plane 1102 and the grid 1103 increases with increasing distance from the driver 1101. The grid 1103 is perforated. According to at least one embodiment, the perforations of the grid 1103 are regular and circular.

Fig. 12 is a cross-sectional view of a grille and ground plane of a speaker system in accordance with at least one embodiment. The device comprises drivers 1201, ground plane 1202 and grid 1203. Driver 1201 is mounted in an aperture defined in ground plane 1202. The distance between ground plane 1202 and grid 1203 decreases with increasing distance from driver 1201. The grill 1203 is perforated. According to at least one embodiment, the perforations of the grating 1203 are regular and circular. However, as can be seen from the perspective view of the driver 1201, although the perforations 1204 of the grill 1203 are circular in the direction of the axis of the driver 1201, the perforations of the grill 1203 are elliptical as the angle relative to the axis of the driver 1201 increases. As the angle increases, the ratio of the major axis of each apparent ellipse to the minor axis of the same apparent ellipse also increases. Thus, away from the axis of the actuator 1201, the apparent ellipse formed by the circular aperture defined in the grill 1203 appears to be closer to the slit than to a circle. Thus, the perforations 1205 that are distal to the axis of the actuator 1201 appear elliptical from the perspective of the actuator 1201. This phenomenon, which causes an apparent ellipse, can be seen by comparing the larger angle 1210 formed between lines of sight 1206 and 1207 aligned with the edges of the perforation 1204 with the smaller angle 1211 formed between lines of sight 1208 and 1209 aligned with the edges of the perforation 1205. The angle and distance between the observation point at the driver 1201 and the respective perforations 1204 and 1205 produce an apparent diameter 1212 of the apparent circular perforation 1204 and an apparent short diameter 1213 of the apparent elliptical perforation 1205. As can be seen, apparent minor diameter 1213 is less than apparent diameter 1204, which makes it appear that perforations 1205 are elliptical. Because it is believed that the slot holes have a different effect on the propagation, reflection and diffraction of sound pressure waves than the circular holes, perforations close to the apparent ellipse of the slot holes may be used to advantage to affect sound pressure waves such as those generated by the driver 1201.

Fig. 13 is a cross-sectional view of a grille and ground plane of a speaker system in accordance with at least one embodiment. The device includes a driver 1301, a ground plane 1302 and a grid 1303. Driver 1301 is mounted in an aperture defined in ground plane 1302. The distance between the ground plane 1302 and the grating 1303 decreases with increasing distance from the driver 1301. The grill 1303 is perforated. The acoustic pressure waves 1304 generated by the driver 1301 interact or interact with the grating 1303 and its perforations. According to at least one embodiment, the relationship of the perforations of the grill 1303 to the ground plane 1302 causes the air movement speed to vary as a function of distance from the drive. It should be appreciated that in practice it may be seen that the directivity or directivity of the loudspeaker system may be affected by the interaction of the multiple sound pressure wavefronts or wavefronts emitted by the multiple point sources formed by the perforations in the multiple grills 1303.

The ratio and manner in which the distance between the ground plane 1302 and the grille 1303 varies with distance from the driver 1301 can affect the directivity or directivity of the speaker system. The ratio and manner of the changes depends on the relative shapes of the ground plane 1302 and the grating 1303 and may be, for example, a function of the distance from the driver 1301. The grating 1303 and the ground plane 1302 can each have a variety of shapes, including planar, conical, parabolic, spherical, hyperbolic, or elliptical. For example, in accordance with at least one embodiment, the ground plane 1302 is curved, hyperbolic in shape, with a radius of curvature approaching that of the driver 1301 of about 20 feet and the grating 1303 may be a planar shape.

The size, shape, and spacing of the perforations in the grille 1303 can be varied to affect the directivity or directivity of the speaker system. For example, the ratio of the surface area of the solid portion of the grill 1303 surrounding the perforations to the surface area defined by the perforations will affect the portion of the acoustic wave energy of the driver 1301 that is reflected back toward the ground plane 1302 by the solid portion of the grill 1303 relative to the transmitted portion of the acoustic wave energy of the driver 1301 that is transmitted through the perforations of the grill 1303. Additionally or alternatively, the characteristics of the grille 1303, the characteristics of the driver 1301 and the ground plane 1302, and other characteristics of the speaker system (e.g., the size and shape of the speaker system housing and ports) are changed, whichever may also be changed to adjust or modify the sound pattern from the speaker system. For example, according to at least one embodiment, the grill 1303 may be formed from a perforated metal plate or sheet construction commonly used in HVAC ventilation grill types. According to at least one embodiment, the grid 1303 may have circular holes, wherein the ratio of the surface area of the solid portion of the grid 1303 surrounding the perforations to the surface area defined by the perforations is between 0.5 and 3. According to at least one embodiment, this ratio may be between 1 and 2.5. According to at least one embodiment, the size of the grid 1303 may be approximately 2 feet by 1 foot, and the drive 1301 may be coupled to a port having a cross-sectional area that increases with increasing distance from the drive 1301.

Fig. 14 shows a flow diagram of a method for changing a sound pattern of a speaker system according to at least one embodiment. The method starts in step 1401 with a driver installed in a ground plane. According to at least one embodiment, step 1401 may include any of steps 1403, 1404, 1405, or 1406. In step 1403, the driver is mounted in a flat ground plane. In step 1404, the driver is installed in the conical ground plane. In step 1405, the driver is mounted in the raised ground plane. In step 1406, the driver is installed in the recessed ground plane. The convex ground plane or the concave ground plane may have a simple curved surface, such as a parabolic, spherical, hyperbolic, or elliptical curved surface, or it may have a more complex surface, having at least one curved surface or at least one non-curved surface (e.g., a combination of curves of different shapes, directions, and/or orientations).

From step 1401, the method continues to step 1402, where a perforated grid is installed in relation to the driver and the ground plane such that a distance between the perforated grid and the ground plane conforms to a desired function of the distance from the driver. For example, in one or more embodiments, the desired function may be such that the distance between the grating and the ground plane increases with distance from the driver, decreases with distance from the driver, remains the same, or varies in a more complex manner. According to at least one embodiment, step 1402 may include any of steps 1407, 1408, 1409, or 1410. In step 1407, the installed perforated grid is a planar perforated grid. In step 1408, the installed perforated grid is a conical perforated grid. In step 1409, the mounted perforated grid is a raised perforated grid. In step 1410, the mounted perforated grid is a surface recessed perforated grid. The raised perforated grid or the recessed perforated grid may have a simple curved surface, such as a parabolic, spherical, hyperbolic, or elliptical curved surface, or it may have a more complex surface, having at least one curved surface or at least one non-curved surface (e.g., a combination of curves of different shapes, directions, and/or orientations).

Thus, methods and apparatus for a speaker assembly are described. While the invention has been described with respect to certain specific embodiments, it will be apparent to those skilled in the art that the inventive features of this invention are applicable to other embodiments as well, all of which are intended to fall within the scope of the invention.

Claims (27)

1. A method, comprising:

forming a speaker frame so as to define a driver housing portion, a horn portion, and a conformal portion;

a driver aperture defining the driver housing portion and a port hole of the horn portion;

connecting a driver and a ground plane to the speaker frame adjacent the driver aperture;

applying a rear baffle plate to a first conformal portion surface of the conformal portion of the speaker frame, wherein the rear baffle plate defines a horn chamber wall of a horn chamber of the horn section, the horn wall having a cross-sectional area that increases with increasing distance from the driver housing portion; and

applying a grille to a second conformal portion surface of the conformal portion of the speaker frame, wherein the applied grille bonds the speaker frame to the rear acoustic panel, wherein a distance between the grille and the ground plane is a function of a distance from the driver.

2. The method of claim 1, wherein the function is such that the distance between the grating and the ground plane decreases with increasing distance from the driver.

3. The method of claim 1, wherein the function is such that the distance between the grating and the ground plane increases with increasing distance from the driver.

4. The method of claim 1 wherein the ground plane is conical.

5. The method of claim 1, wherein the ground plane is recessed relative to the grating.

6. The method of claim 1, wherein the ground plane is raised relative to the grating.

7. The method of claim 6, wherein the grid is flat.

8. The method of claim 1, wherein the grid is conical.

9. The method of claim 1, wherein the grating is recessed relative to the ground plane.

10. The method of claim 1, wherein the grating is raised relative to the ground plane.

11. An apparatus, comprising:

a speaker frame defining a driver housing portion, a horn portion, and a conformal portion, the driver housing portion defining a driver aperture and the horn portion defining a port hole;

a ground plane adjacent the speaker frame proximate the driver aperture;

a driver adjacent the speaker frame proximate the driver aperture;

a rear baffle having a first rear baffle surface, wherein a first conformal portion surface of the conformal portion of the speaker frame substantially conforms to the first rear baffle surface, wherein the first rear baffle surface defines a horn chamber wall of a horn chamber of the horn portion, the horn chamber having a cross-sectional area that increases with increasing distance from the driver housing portion; and

a grille adjacent a second conformal portion surface of the conformal portion of the speaker frame, wherein the grille bonds the speaker frame to the rear soundboard, wherein a distance between the grille and the ground plane is a function of a distance from the driver.

12. The device of claim 11, wherein the function is such that the distance between the grating and the ground plane decreases with increasing distance from the driver.

13. The device of claim 11, wherein the function is such that the distance between the grating and the ground plane increases with increasing distance from the driver.

14. The apparatus of claim 11, wherein the ground plane is conical.

15. The apparatus of claim 11, wherein the ground plane is recessed relative to the grating.

16. The apparatus of claim 11, wherein the ground plane is raised relative to the grating.

17. The apparatus of claim 11, wherein the grid is flat.

18. The apparatus of claim 11, wherein the grid is conical.

19. The apparatus of claim 11, wherein the grating is recessed relative to the ground plane.

20. The apparatus of claim 11, wherein the grating is raised relative to the ground plane.

21. An apparatus, comprising:

a ground plane defining a speaker driver aperture;

a speaker driver mounted in the speaker driver aperture; and

a perforated grille mounted such that a distance between the perforated grille and the ground plane is a function of a distance from the speaker driver.

22. The device of claim 21, wherein the function is such that the distance between the grating and the ground plane decreases with increasing distance from the driver.

23. The device of claim 21, wherein the function is such that the distance between the grating and the ground plane increases with increasing distance from the driver.

24. The apparatus of claim 21 wherein the ground plane is conical.

25. The apparatus of claim 21, wherein the ground plane is recessed relative to the perforated grid.

26. The apparatus of claim 21, wherein the ground plane is convex with respect to the perforated grid.

27. The apparatus of claim 21, wherein the grid is flat.