Abstract:
An improved in-wall speaker assembly providing better performance and less intrusion than prior art speakers. The speaker assembly is oriented such that the driver fires vertically, parallel to the wall studs, rather than horizontally and perpendicular to the wall studs. The cone and surround of the speaker assembly are generally rectangular and/or conform to the area available between studs. Additionally, the cone is not attached to the voice coil, but is connected to the voice coil by a shaft which transmits the energy from the voice coil to the cone. In another aspect of the invention, the cabinet or housing includes two housings.

Description:
PRIORITY CLAIM 
     The present application claims priority to U.S. Provisional App. No. 60/726,439 filed Oct. 13, 2005 to Hall et al. titled “In-Wall Loudspeaker,” and hereby incorporated by reference. 
    
    
     FIELD OF THE INVENTION 
     This invention relates generally to speakers and, more specifically, to in-wall mounted speaker systems. 
     BACKGROUND OF THE INVENTION 
     There is a growing demand for custom installed in-wall speakers with maximum performance and minimal intrusion to the interior of the home. One limitation on the configuration of in-wall speakers is the limited volume; in most situations, walls have 16″ center, 3.5″ depth wall studding. This limitation forces speakers with circular drivers with a diameter of 3.5″ or larger to fire perpendicular to the plane of the wall. Speakers installed in this orientation cause undesirable vibration in the wall and are limited to a shallow cabinet with a restricted depth, limiting driver throw. 
     SUMMARY OF THE INVENTION 
     One form of the invention provided is an improved in-wall speaker assembly providing better performance and less intrusion than prior art speakers. The speaker assembly is oriented such that the driver reciprocates vertically, parallel to the wall studs, rather than horizontally and perpendicular to the wall studs. This orientation allows a greater speaker throw and larger cabinet area, reduces vibration in the wall, and reduces the size of the opening and grille in the wall to minimize intrusion. 
     The cone and surround of the speaker assembly are generally rectangular and/or conform to the area available between studs, in order to take maximum advantage of the space restriction caused by the configuration of the studs and drywall. 
     Additionally, in some forms of the invention the cone is not attached to the voice coil, but is connected to the voice coil via a shaft which transmits the energy from the voice coil to the cone. Prior art speakers have the voice coil attached to the cone and the spider attached to the voice coil. With the cone attached to the surround, the combination of the surround and the spider(s) create the speaker suspension system that both suspends the voice coil/cone assembly and provides linear travel through the magnetic gap between the motor housing and the magnets. This arrangement is a severe limitation when limited to the 3.5″ width available to in-wall speakers. In this example, the voice coil and cone are separated by a shaft which transmits energy from the voice coil to the cone. The shaft and voice coil are kept centered in the gap by spiders located on the shaft, which allows for a larger spider assembly with a larger ratio of inner to outer diameter to be used, while still meeting the 3.5″ width limitation. 
     In other examples of the invention, the cabinet or housing includes two housings. The first housing is mounted to the studs before drywall installation. The second housing containing the driver is mounted after drywall installation. In this way, expensive components are not installed until the house is securable against theft. Therefore, a smaller opening in the drywall is required to install the driver housing. 
     As will be readily appreciated from the foregoing summary, the invention provides an improved speaker assembly for in-wall speaker applications. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Preferred and alternative embodiments of the present invention are described in detail below with reference to the following drawings: 
         FIG. 1A-E  are various views of a speaker system formed in according with the present invention; 
         FIG. 2  is an perspective view of a second housing of the speaker system mounted in a wall; 
         FIG. 3  is an isometric view of the second housing of the speaker system; 
         FIG. 4A  is an isometric view,  FIG. 4B  is an isometric exploded view of a driver assembly according to the present invention, and  FIG. 4C  is a top partial view of the driver assembly showing a magnetic gap; 
         FIG. 5  is an exploded isometric view of a cone of the speaker assembly of  FIG. 3 ; 
         FIG. 6A  is an isometric view of a shaft of the speaker assembly of  FIG. 3 , and  FIG. 6B  is an isometric view of the shaft with attached spiders of the speaker assembly of  FIG. 3 ; 
         FIG. 7  is an isometric view of a coil adapter of the speaker assembly of  FIG. 3 ; and 
         FIG. 8A  is a top view and  FIG. 8B  is a side cross-sectional view of one of the spiders of the speaker assembly of  FIG. 3 . 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     As shown in  FIG. 1A , a speaker system  10  is mounted within a wall  23  between studs  25   a ,  25   b . The speaker system includes housings  16 ,  22  that may be directly secured to the studs  25   a ,  25   b  by means of mounting brackets  17 ,  32  or the like. In typical construction, the studs  25   a ,  25   b  have a depth of 3½ inches and are spaced 16 inches apart. The housings  16 ,  22  are therefore sized to fit within a column of space having this cross sectional area. In some instances studs  25   a ,  25   b  having a depth of 4 or 6 inches are used. In such embodiments, the housings  16 ,  22  may be made large enough to substantially occupy the entire cross sectional area. The housings  16 ,  22  are covered by drywall  23  on either side of the housings  16 ,  22 . In practice, the second housing  22  is installed before the drywall  23 . A vent opening is formed in the drywall  23  to install the driver housing  16 . In this way, the more expensive driver housing  16  and contained components are not installed until the structure is complete enough to be secure from theft, and the smaller vent opening in the drywall  23  is needed to install the smaller driver housing  16 . 
     Referring to  FIGS. 1B-E ,  2  and  3 , the speaker system  10  includes a cone or radiating member  12  serving to cause acoustical waves in the surrounding air. A driver  14  secures to the cone  12  and causes the cone  12  to vibrate according to a signal supplied to the driver  14 . The cone  12  has an elongate shape, such that in a horizontal plane the width of the radiating member is larger than its depth. The cone  12  and driver  14  are vertically aligned having the driver  14  either above or below the cone  12 . 
     The cone  12  and driver  14  mount within a driver cabinet (or driver housing or first housing)  16  having an elongate shape, such as a narrow rectangle, in the horizontal plane. The cone  12  is positioned within an opening  18  at the top of the housing  16 . A gasket  15  which may be made of foam is attached between the driver  14  and the housing  16 . A surround (or sealing member or resilient seal)  20  surrounds the cone  12  and mounts the cone  12  to the housing  16 . The surround  20  is formed of a flexible resilient material, such as rubber, such that the cone  12  has a vertical range of motion relative to the housing  16 . The surround  20  prevents substantial passage of air past the cone  12 . The housing  16  is attached to adjacent studs  25   a ,  25   b  ( FIG. 3 ) with brackets  17  located on opposite sides of the housing  16 . 
     A second cabinet or housing  22  secures within the wall near the driver housing  16 . The second housing  22  is preferably positioned near the end of the driver housing  16  opposite the cone  12 . The second housing  22  provides a reservoir of air that resonates according to vibration of the cone  12 . The second housing  22  insulates the wall or drywall  23  from the vibration of the speaker system  10 , as well as isolating the back wave of the driver  14  from the front wave. 
     The second housing  22  is fluidly connected to the driver housing  16  by one or more tubes  24  that attach to second housing apertures  26  and driver housing apertures  28  with clamps  30  or other attachment means. The second housing  22  is attached to adjacent studs  25   a ,  25   b  with brackets  32  located on opposite sides of the second housing  22 . 
       FIGS. 4A ,  4 B and  4 C show an isometric view, an exploded isometric view, and a top partial view, respectively of the driver  14  along with the cone  12  and the surround  20 .  FIG. 4A  shows the surround  20  attached to the cone  12  and a plastic basket  36 . The basket  36  is attached to the surround  20  via an adhesive, and is further attached to a steel motor housing  38  and a polycarbonate composite rear spider housing  40  with a plurality of screws  41 . The cone  12  is connected to a shaft  42  with a shaft cap  44 . A pair of connectors  39   a ,  39   b  is attached to flexible wire leads (not shown) which provide an electrical connection to the voice coil assembly  46 . A thermal regulator  43  is attached with a pair of screws  45  to the motor housing  38  and acts to break the electrical connection between a voice coil assembly  46  and the connectors  39   a ,  39   b  when the temperature exceeds a predetermined level. 
     The motor housing  38  contains the voice coil assembly  46 , three magnets  48   a ,  48   b ,  48   c , which may be made of neodymium or other suitable material, and a steel top plate  50 , all supported by a steel T-yoke  52  attached to the bottom of the motor housing  38  with a plurality of screws  54 . A magnetic gap  55  is located between the outer edges of the top plate  50  and magnets  48   a ,  48   b ,  48   c  and the inner surface of the motor housing  38 . Above and coupled to the voice coil assembly  46  is a coil adapter  56  which facilitates transfer of energy from the voice coil assembly  46  to the shaft  42 . 
     Two pair of spiders or resilient suspension members  58   a ,  58   b  and  58   c ,  58   d  located along the length of and attached to the shaft  42  near the top and bottom of the shaft  42  via first and second adapters  62 ,  68  keep the shaft  42  and voice coil assembly  46  centered in the magnetic gap  55 . The outer diameters of the spiders  58   a ,  58   b  and  58   c ,  58   d  are connected to the basket  36  and the motor assembly  38 , respectively, via a spider landing  64  and the rear spider housing  40 . A pair of spider clamps  60   a ,  60   b  connect respective pairs of spiders  58   a ,  58   b  and  58   c ,  58   d  together. The first adapter  62  prevents contact between the spider  58   a  and the cone  12 . The spider landing  64  prevents contact between the spider  58   b  and the coil adapter  56 , and is attached to the basket  36  with a plurality of screws  66 . The second pair of spiders  58   c ,  58   d  are located in the rear spider housing  40 . A bottom shaft cap  70  is attached to the bottom of the shaft  42  and affixes the second adapter  68  to the shaft  42 . 
       FIG. 5  is an exploded isometric view of the cone  12 . The cone  12 , in one embodiment, includes three layers. The top and bottom layers  72 ,  76  are made of carbon fiber, aluminum, Kevlar™, or other suitable lightweight materials, and the middle layer is made of white rohescell, or any other lightweight rigid filler material. Each layer  72 ,  74 ,  76  includes a shaft aperture  78 ,  80 ,  82  to receive the shaft  42  and shaft cap  44 . 
       FIG. 6A  shows an isometric view of the shaft  42 , and  FIG. 6B  shows an isometric view of the first adapter  62  with attached spiders  58   a ,  58   b  (and representative of the second adapter  68  with attached spiders  58   c ,  58   d ) shown spaced apart for clarity. The shaft  42  is preferably made of aluminum or other nonmagnetic rigid material and defines a larger diameter section  84  with two smaller diameter sections  86   a ,  86   b . Section  86   a  is attached to the pair of spiders  58   c ,  58   d , and section  86   b  is attached to the cone  12 , the pair of spiders  58   a ,  58   b , and the voice coil adapter  56 . The spiders  58  are sized to fit the smaller diameter sections  86   a ,  86   b  via adapters  62 ,  68  and are positioned adjacent the larger diameter section  84  as shown in  FIG. 6B  with the motor housing  38  and voice coil assembly  46  located between the spiders on the larger diameter section  84 . 
       FIG. 7  is an isometric view of the coil adapter  56 . The adapter  56  is preferably made of a polycarbonate composite or other lightweight, nonmagnetic material. The adapter  56  is rigid and lightweight and connects the voice coil assembly  46  to the shaft  42  to provide a snug fit between the larger diameter voice coil assembly  46  and the smaller diameter shaft  42 . The adapter  56  is cone-shaped to increase rigidity and vented to minimize drag. 
       FIG. 8A  is a top view and  FIG. 8B  is a side cross-sectional view of a spider  58 . The spider  58  is made of an aramid fiber, preferably Nomex™, but can also be made of cotton or other fiber having the desired properties. 
     While the preferred embodiment of the invention has been illustrated and described, as noted above, many changes can be made without departing from the spirit and scope of the invention. Accordingly, the scope of the invention is not limited by the disclosure of the preferred embodiment. Instead, the invention should be determined entirely by reference to the claims that follow.