Abstract:
A low profile loudspeaker assembly is disclosed. The loudspeaker assembly includes a housing in which at least one driver is mounted. The housing includes a first aperture and a second aperture wherein the first and second apertures are on opposite sides of the housing. The driver includes a cone coupled to a driver magnet assembly for generating sound. The cone is aligned with the first aperture to permit the direct passage of sound from the loudspeaker and the driver magnet assembly is seated within the second aperture exposing a portion of the driver magnet assembly to the exterior of the housing, wherein the depth to which the driver magnet assembly sits within the second aperture facilitates a reduction in the profile of the loudspeaker.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This U.S. Patent Application is based upon U.S. Provisional Patent Application Ser. No. 60/120,123, filed Feb. 16, 1999, entitled “LOW PROFILE SUBWOOFER ASSEMBLY” and No. 60/158,304, filed Oct. 10, 1999, entitled “LOW PROFILE LOUDSPEAKER ASSEMBLY”. 
    
    
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The invention relates to loudspeaker assemblies. More particularly, the present invention relates low profile loudspeaker assemblies. The loudspeaker assemblies are shaped and dimensioned for positioning within a variety of previously unused spaces found within an aircraft. 
     2. Description of the Prior Art 
     The current global community has made it possible for people from around the country, and around the world, to interact for both business and personal reasons. For many people, this requires that they spend considerable time traveling from one location to another location. More often than not, these people travel in aircraft. 
     Whether these people travel in private or commercial aircraft, they desire high quality entertainment during the many hours they spend within the confines of an aircraft. However, while high quality entertainment, for example, digital video with CD quality sound, is readily available for theater and home use, the weight and size requirements for use in aircraft make it very difficult to incorporate high fidelity systems within an aircraft. This problem is especially pronounced for audio speaker assemblies when one attempts to meet the size, weight and shape requirements for use in aircraft. 
     In the aircraft industry great priority is placed upon component weight and size reduction. In addition, spacing and positioning of the speaker assemblies is a great priority to those optimizing the operation of aircraft. The size, weight and shape of conventional terrestrial speaker assembly designs adversely affect range and payload. These concerns are notable when one attempts to make changes within smaller private jets. For example, a small increase in the weight carried by an aircraft results in a substantial increase in the fuel consumption of the aircraft. In addition, the limited space available within an aircraft dictates the use of any space within the aircraft be carefully considered by those responsible for ensuring the comfort of passengers. 
     Lightweight and compact audio speakers are currently available. These speakers, however, substantially compromise sound quality for reductions in size and weight. An individual wishing to add an audio system to an aircraft must make a choice between high fidelity speakers not suiting the size and weight requirements of the aircraft and lower quality speakers providing desirable size and weight characteristics. 
     A need, therefore, exists for a speaker assembly providing high fidelity sound, while also meeting the size and weight requirements of an aircraft. The present invention provides such a speaker assembly. 
     SUMMARY OF THE INVENTION 
     It is, therefore, an object of the present invention to provide a low profile loudspeaker assembly. The loudspeaker assembly includes a housing in which at least one driver is mounted. The housing includes a first aperture and a second aperture wherein the first and second apertures are on opposite sides of the housing. The driver includes a cone coupled to a driver magnet for generating sound. The cone is aligned with the first aperture to permit the direct passage of sound from the loudspeaker and the driver magnet is seated within the second aperture exposing a portion of the driver magnet to the exterior of the housing, wherein the depth to which the driver magnet sits within the second aperture facilitates a reduction in the profile of the loudspeaker. 
     It is a further object of the present invention to provide a seat assembly including a seat and the loudspeaker assembly described above secured beneath the seat. 
     It is another object of the present invention to provide a loudspeaker assembly including a housing in which at least a first driver is mounted, the housing including a first wall and a second wall opposite the first wall. The first driver is compression fit between the first wall and the second wall. 
     Other objects and advantages of the present invention will become apparent from the following detailed description when viewed in conjunction with the accompanying drawings, which set forth certain embodiments of the invention. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a perspective view of the present subwoofer with the internal components shown in phantom. 
     FIG. 2 is a side view of a seat with the present subwoofer secured thereto. 
     FIG. 3 is a top view of the present subwoofer. 
     FIG. 4 is a cross sectional view taken along the line IV—IV in FIG.  3 . 
     FIG. 5 is a side view of the present subwoofer. 
     FIG. 6 is a rear view of the present subwoofer. 
     FIG. 7 is a cross-sectional view of another embodiment of the present loudspeaker assembly. 
     FIG. 8 is a perspective view of the housing of the loudspeaker assembly shown in FIG.  7 . 
     FIG. 9 is a perspective view of the loudspeaker assembly shown in FIG. 7 with the top wall removed. 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     The detailed embodiments of the present invention are disclosed herein. It should be understood, however, that the disclosed embodiments are merely exemplary of the invention, which may be embodied in various forms. Therefore, the details disclosed herein are not to be interpreted as limited, but merely as the basis for the claims and as a basis for teaching one skilled in the art how to make and/or use the invention. 
     With reference to FIGS. 1 through 6, a low profile loudspeaker assembly, more specifically, a subwoofer  10 , is disclosed. The subwoofer  10  is designed for positioning beneath an aircraft seat  12 . In accordance with the preferred embodiment of the present invention, the subwoofer  10  has been designed for mounting beneath a 16 G AMP aircraft seat, although the present subwoofer may be used in conjunction with other seats without departing from the spirit of the present invention. The need for the lower profile, discussed below in greater detail, is necessitated by the limited clearance between the base of the 16 G AMP aircraft seat and the floor. 
     Given that the present subwoofer  10  was designed for positioning beneath an AMP aircraft seat, the subwoofer  10  incorporates a unique design which reduces the profile of the subwoofer  10  without sacrificing sound quality. The reduced profile is achieved by positioning the driver magnet assembly  14  of the driver  16  within the honeycomb walls of the housing  20 . In this way, space that would have simply been occupied by the bottom wall  22  of the subwoofer housing  20  is used in an effective manner to store a portion of the driver magnet assembly  14 . In addition, a slight portion of the driver magnet assembly  14  extends below the housing  20 . This also contributes to the reduction of the subwoofer profile. This improvement in the use of space is critical to fitting the present subwoofer  10  within the allowable space available under the AMP aircraft seat  12 . 
     By cutting away a portion of the bottom wall  22  of the housing  20 , the weight of the housing  20  is also reduced (for example, by about 3.2 ounces). While such a reduction in weight appears to be minor, any weight reduction within an aircraft is considered to be a substantial benefit. 
     Specifically, and with reference to FIGS.  1  and  3 - 6 , the subwoofer  10  includes a housing  20  having a top wall  24 , a bottom wall  22 , a front wall  26 , a rear wall  28  and side walls  30 ,  32 . As briefly discussed above, the housing  20  is preferably manufactured from honeycombed aluminum, and as such includes an interior wall  50 , a honeycomb center  52 , and an exterior wall  54 . 
     The side walls  30 ,  32  include indented sections  34 ,  36 . As such, the distance between the side walls decreases as the housing  20  extends from the top wall  24  to the bottom wall  22 . The indented sections  34 ,  36  allow for the positioning of the subwoofer  10  beneath the AMP aircraft seat  12 . The top wall  24  of the housing  20  is formed separately from the remainder of the housing, and is secured to inwardly extending ledges  40  formed along the front wall  26 , rear wall  28  and side walls  30 ,  32  of the housing  20 . Screws  38  securely attach the top wall  24  to the remainder of the housing. 
     The top wall  24  includes a primary aperture  41 , a sound port  42  and a grommet aperture  44 . The primary aperture  41  is aligned with the cone  46  of the driver  16  and permits the direct passage of sound from the subwoofer  10 . The top edge  17  of the driver  16  is secured to the interior of the top wall  24  adjacent the primary aperture  41 . As such, the driver  16  is securely mounted between the top wall  24  and the bottom wall  22  in a manner that will be discussed below in greater detail. The sound port  42  allows for the indirect passage of sound from the driver  16  to increase the efficiency of the present subwoofer  10 . The grommet aperture  44  is shaped and dimensioned for the passage of wires within the housing  20 . 
     A driver aperture  48  is formed in the bottom wall  22  of the housing  20 . As shown in FIGS. 1 and 4, the driver magnet assembly  14  of the driver  16  is seated within the driver aperture  48 . Specifically, the bottom wall  22  of the housing  20  is cut open such that the interior wall  50  and the honeycomb center  52  are flush. The exterior wall  54  is cut such that it provides a slightly smaller opening than the remainder of the aperture. In this way, the exterior wall  54  forms a ledge  55  upon which the driver magnet assembly  14  is seated. 
     The driver magnet assembly  14  sits within the space defined by aperture  48  formed by the interior wall  50  and the honeycomb center  52 . The ledge  55  supports the driver magnet assembly  14  such that the driver magnet assembly  14  is seated within the driver aperture  48  to a depth which reduces the profile of the subwoofer  10  sufficiently to facilitate placement beneath the aircraft seat  12 . 
     The driver magnet assembly  14  of the driver  16  is wrapped in nonflammable foam  56  and is compression fit within the driver aperture  48  to essentially become part of the subwoofer housing  20 . In addition to allowing for the compression fit of the driver magnet assembly  14  within the driver aperture  48 , the foam  56  also prevents rattling of components within the subwoofer  10 . While the driver  16  is compression fit in accordance with the preferred embodiment of the present invention, other coupling techniques may be used in securing the driver within the driver aperture  48  without departing from the spirit of the present invention. 
     By positioning the driver magnet assembly  14  within the bottom wall  22  of the housing  20  approximately an additional ¼ inch is saved in the profile of the subwoofer  10 . This provides critical additional space for reducing the profile of the present subwoofer  10 . While specific dimensions are disclosed for the present embodiment, the concepts surrounding the present invention may be applied in various applications without departing from the spirit of the present invention. 
     The subwoofer  10  is assembled in the following manner. The edge  58  of the driver aperture  48  is first treated with epoxy. The driver magnet assembly  14  is then wrapped in foam  56  and compression fit within the driver aperture  48 . The driver  16  is then wired. The top wall  24  is secured to the remainder of the housing  20 , securely fitting the driver  16  between the top wall  24  and the bottom wall  22 . The subwoofer  10  is then prepared for attachment under the aircraft seat  12 . 
     With reference to FIG. 2, the subwoofer  10  is mounted beneath an aircraft seat  12  such that top wall  24  faces the bottom  58  of the seat  12 , while the bottom wall  22  faces the floor  60  upon which the seat  12  is mounted. The space in which the subwoofer  10  must be positioned is very small and the space savings based upon the reduced profile allows for use of the small space between the seat  12  and the floor  60 . 
     In addition to reducing the profile of the subwoofer, the present design improves the structural integrity of the subwoofer. By compression fitting the driver magnet within the drive aperture as discussed above, the driver becomes part of the internal bracing of the housing and adds to the structural stability of the subwoofer. The present design also provides a natural heat sink for cooling the driver. Specifically, the driver magnet is exposed to the interior of the aircraft, which acts as a heat sink for cooling the driver. 
     The resulting subwoofer has a length of approximately 11.3862 inches, a width of approximately 10.625 inches and a depth of approximately 3.0650 inches. Other dimensions are noted in FIGS. 3,  5  and  6 . 
     In practice, multiple subwoofers are commonly mounted within an aircraft. The number of subwoofers employed is determined by the size of the aircraft and the needs of the aircraft owners. Those of ordinary skill in the art will certainly appreciate the need for specific positioning of the subwoofers within the aircraft to optimize the generated sound. 
     With reference to FIGS. 7 through 9, a loudspeaker assembly  110  in accordance with the present invention is disclosed. The loudspeaker assembly  110  is designed for positioning within small unused cavities found within the body of an aircraft. In accordance with a preferred embodiment of the present invention, the loudspeaker assembly  110  is designed for mounting within the side wall passenger service unit of newly developing jets. However, those skilled in the art will readily appreciate that the size and weight of the present loudspeaker assembly  110  make possible a wide variety of possible mounting positions within the body of an aircraft. 
     The present loudspeaker assembly incorporates a high frequency driver  112 , a microwoofer  114 , i.e., a lower frequency driver or low frequency midrange, and crossover network (not shown) within a very compact housing  116 . While the present loudspeaker assembly  110  provides a wide range of sounds, the loudspeaker assembly  110  may be supplemented by the addition of one, or more, subwoofers positioned at various locations within the aircraft. 
     The size, shape and weight of the loudspeaker assembly  110  are minimized by implementing a variety of unique design techniques. Briefly, the loudspeaker assembly  110  positions the microwoofer magnet assembly  118  within the bottom wall  120  of the housing  116  to lower the profile, and reduce the weight, of the loudspeaker assembly  110 , compression fits the microwoofer  114  within the housing  116  to reduce weight, improve sound characteristics and add to the overall structural stability of the loudspeaker assembly  110 , and utilizes a microwoofer  114  to ultimately reduce the size and weight of the loudspeaker assembly  110 . 
     In addition, by reducing the size of the loudspeaker assembly  110  in the manner discussed above, the mass of the loudspeaker assembly  110  is reduced, and the gauge of the structural components, i.e., the screws, pins, etc., employed in the fabrication of the present loudspeaker assembly are also reduced. This results in further weight savings critical to the overall usefulness of the loudspeaker assembly  110 . 
     With the foregoing in mind, and with reference to FIGS. 7 and 8, the loudspeaker assembly  110  includes a housing  116  having a top wall  122 , a bottom wall  120 , and four side walls  124   a-d.  The housing  116  is preferably manufactured from aluminum, although other lightweight, structurally rigid materials may be used without departing from the spirit of the present invention. The side walls  124   a-d  are formed with outwardly extending mounting flanges  126  used in coupling the present loudspeaker assembly  110  at predetermined locations with the body of the aircraft. 
     The top wall  122  of the housing  116  is formed separately from the remainder of the housing  116 , and is screwed to the inwardly extending mounting flanges  127  respectively formed along the top edges  130  of the side walls  124   a-d  of the housing  116 . The top wall  122  includes a primary aperture  132  shaped and dimensioned to be slightly smaller than the open end  134  of the microwoofer cone  136  and a secondary aperture  138  shaped and dimensioned to receive the open end  140  of the high frequency driver  112  cone. The high frequency driver  112  is adhesively bound to the top wall  122  adjacent the secondary aperture  138  in a conventional manner. 
     The primary aperture  132  is aligned with the microwoofer cone  136  and permits the direct passage of sound from the microwoofer  114 . The top edge  142  of the microwoofer cone  136  engages the top wall  122  adjacent the primary aperture  132 . As such, the microwoofer  114  is securely mounted between the top wall  122  and the bottom wall  120  in a manner that will be discussed below in greater detail. 
     A driver aperture  144  is formed in the bottom wall  120  of the housing  116 . As shown in FIGS. 7 and 9, the microwoofer magnet assembly  118  is seated within the driver aperture  144 . Specifically, the bottom wall  120  of the housing  116  is cut open to form the driver aperture  144 . The driver aperture  144  is shaped and dimensioned to receive the smaller diameter bottom section  145  of the microwoofer magnet assembly  118  while permitting the wide portion  146  of the microwoofer magnet assembly  118  to sit upon the interior surface  148  of the bottom wall  120 . The microwoofer magnet assembly  118  sits within the driver aperture  144  such that it is substantially flush with the exterior surface  150  of the bottom wall  120 . 
     The microwoofer magnet assembly  118  is wrapped in nonflammable foam (not shown) and is compression fit with the driver aperture  144  to essentially become part of the housing  116 . In addition to allowing for the compression fit of the microwoofer magnet assembly  118  within the driver aperture  144 , the foam also prevents rattling of components within the present loudspeaker assembly  110 . While the microwoofer  114  is compression fit in accordance with the preferred embodiment of the present invention, other coupling techniques may be used in securing the microwoofer  114  within the driver aperture  144  without departing from the spirit of the present invention. 
     By positioning the microwoofer magnet assembly  118  within the bottom wall of the housing, valuable space is saved in the profile of the loudspeaker assembly  110 . This provides critical additional space for reducing the profile of the loudspeaker assembly  110  in accordance with the present invention. 
     By forming the top wall  122  separately from the remainder of the housing  116 , the top wall  122  may be secured to the remainder of the housing  116  in such a manner that the microwoofer  114  is compression fit between the bottom wall  120  and the top wall  122 . Specifically, the microwoofer  114  is shaped and dimensioned to exactly fit between the top wall  122  and the bottom wall  120  of the housing  116 , with the microwoofer magnet assembly  118  sitting within the driver aperture  144  formed in the bottom wall  120  of the housing  116 . 
     As a result, when the top wall  122  is screwed onto the remainder of the housing  116 , with the microwoofer  114  sitting within the driver aperture  144 , the inner surface  152  of the top wall  122  adjacent the primary aperture  132  presses against the top edge  142  of the microwoofer cone  136  to securely trap the microwoofer  114  between the top wall  122  and the bottom wall  120  of the housing  116 . 
     The compression fit of the microwoofer  114  between the top wall  122  and the bottom wall  120  achieves a weight reduction in that no screws or brackets are required for the mounting of the microwoofer  114 . The top and bottom walls  122 ,  120  act as the mounting bracket for the microwoofer  114 , thereby, obviating the need for screws and other mounting structures. 
     In addition to reducing the profile of the present loudspeaker assembly  110 , the present design improves the structural integrity of the loudspeaker assembly  110 . By compression fitting the microwoofer magnet assembly  118  within the driver aperture  144  and microwoofer  114  between the top wall  122  and the bottom wall  120  as discussed above, the microwoofer  114  becomes part of the internal bracing of the housing  116  and adds to the structural stability of the loudspeaker assembly  110 . As discussed with reference to the prior embodiment, the present design also provides a natural heat sink for cooling the microwoofer. 
     The resulting subwoofer housing has a length of approximately 4.50, a width of approximately 2.5 inches and a depth of approximately 1.12 inches. Other dimensions are noted in FIGS. 7 through 9. In addition to providing a small profile housing which fits many previously unused spaces within an aircraft, the weight of the fully assembled loudspeaker assembly  110  is approximately 10 to 11 ounces, with the microwoofer  114  weighing approximately 4.4 ounces. While specific dimensions are disclosed for the present embodiment, the concepts surrounding the present invention may be applied without departing from the spirit of the present invention. 
     The disclosed size of the present speaker assembly is critical to its use in newly developing aircraft. Specifically, as fuselages are being streamlined to improve the overall efficiency of the aircraft, the passenger compartment is also being moved outwardly. As a result, the space available for mounting supplemental equipment within an aircraft in a manner that does not intrude upon the available space within the passenger compartment is quickly being reduced as the aircraft are being designed more and more efficiently. At the present time, that available window dictates that at most a 2 inch depth is available for the placement of supplemental equipment such as the present loudspeaker assembly. With this in mind, the adept use of space employed in the present loudspeaker assembly results a speaker offering previously unheard of sound in a speaker assembly with a depth profile of less than 2 inches. 
     The present loudspeaker assemblies will be mounted within the aircraft at various locations. The number of speaker assemblies, as well as the exact location of the speaker assemblies is determined by the size of the aircraft and the needs of the aircraft owners. Those of ordinary skill in the art will certainly appreciate the need for specific positioning of the subwoofers within the aircraft to optimize the generated sound. In addition, and as discussed above, the sound generated by presented loudspeaker assembly may be supplemented by the addition of one, or more, subwoofers positioned at various locations within the aircraft. 
     While the preferred embodiments have been shown and described, it will be understood that there is no intent to limit the invention by such disclosure, but rather, it is intended to cover all modifications and alternate constructions falling within the spirit and scope of the invention as defined in the appended claims.