Abstract:
A subwoofer assembly for use within an aircraft including a fuselage having a passenger platform, wherein the passenger platform includes an aisle and a seating area. The subwoofer assembly is shaped and dimensioned for positioning under the aisle. The subwoofer assembly includes a subwoofer housing having a profile shaped to substantially conform to a position beneath the passenger platform under the aisle. The subwoofer housing includes a sound port through which sound is delivered from the subwoofer assembly to a passenger compartment of the aircraft. The subwoofer assembly further including a sound driver mounted within the subwoofer housing for generating predetermined sounds.

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The invention relates to subwoofer assemblies. More particularly, the invention relates to a subwoofer assembly shaped and dimensioned for mounting under the center aisle of 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 necessary for use in aircraft. 
     The aircraft industry places great priority upon component weight and size reductions. In addition, spacing and positioning of speaker assemblies is of great importance 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. 
     The weight and size problems associated with the use of loudspeaker systems within aircraft are very evident when one attempts to incorporate woofers into an aircraft design. Conventional woofers employ substantial housings designed to control the manner in which sound is transmitted from the woofer. The controlled porting of sound employed in conventional woofers necessitates the construction of rather substantial housings. These housings, while controlling the transmission of sound as desired, are commonly beyond the size and weight constraints required for use within an aircraft. 
     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 an aircraft including a fuselage having a passenger platform, wherein the passenger platform includes an aisle and a seating area. The aircraft further includes at least one subwoofer assembly mounted beneath the passenger platform under the aisle. The subwoofer assembly is shaped and dimensioned for positioning under the aisle. The subwoofer assembly includes a subwoofer housing having a profile shaped to substantially conform to a position beneath the passenger platform under the aisle. The subwoofer housing includes a sound port through which sound is delivered from the subwoofer assembly to a passenger compartment of the aircraft. The subwoofer assembly further including a sound driver mounted within the subwoofer housing for generating predetermined sounds. 
     It is also an object of the present invention to provide an aircraft including a sound tube coupled to the sound port for directing sound to the passenger compartment of the aircraft. 
     It is another object of the present invention to provide an aircraft wherein the sound tube is adjustably coupled to the sound port in a manner permitting relative movement. 
     It is a further object of the present invention to provide an aircraft wherein a wall links the aisle to the seating area and the wall includes an opening through which sound from the subwoofer assembly is directed. 
     It is also another object of the present invention to provide an aircraft including a sound tube coupled to the sound port for directing sound to the passenger compartment of the aircraft, wherein the sound tube includes a proximal end coupled to the sound port and a distal end coupled adjacent the opening in the wall. 
     It is yet another object of the present invention to provide an aircraft wherein the aisle is a center aisle and seating areas are positioned on opposite sides of the center aisle. 
     It is still a further object of the present invention to provide an aircraft wherein the subwoofer housing is made from aluminum. 
     It is also an object of the present invention to provide a method for positioning a subwoofer assembly within an aircraft including a passenger platform, the passenger platform including an aisle and a seating area. The method is achieved by mounting a subwoofer assembly beneath the passenger platform under the aisle such that the subwoofer is hidden from the view of a passenger compartment of the aircraft and directing sound from the subwoofer to the passenger compartment of the aircraft. 
     It is another object of the present invention to provide a subwoofer assembly including a subwoofer housing having a sound port through which sound is delivered from the subwoofer assembly to a passenger compartment of the aircraft, a sound driver mounted within the subwoofer housing for generating predetermined sounds, and a relatively adjustable sound tube selectively coupled to the sound port. 
     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 cross sectional view of an aircraft employing the present subwoofer assembly. 
     FIG. 2 is a detailed cross sectional view of the subwoofer assembly installation in accordance with the present invention. 
     FIG. 3 is perspective view of a subwoofer in accordance with the present invention. 
     FIG. 4 is a cross sectional view of a subwoofer in accordance with the present invention. 
     FIG. 5 is a side a cross sectional view of an alternate embodiment of a subwoofer assembly in accordance with the present invention. 
     FIG. 6 is a perspective view of the subwoofer assembly shown in FIG.  5 . 
     FIG. 7 is a side view of the subwoofer assembly shown in FIG.  5 . 
    
    
     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. 
     Referring to FIGS. 1 and 2, the general construction of an aircraft  10  contemplated for use in accordance with the present invention is shown. In accordance with a preferred embodiment of the present invention, the present subwoofer assembly is adapted for use in business class jet aircraft, although those skilled in the art will readily appreciate the many applications within the scope of the present invention. Most business jet aircraft are of low-wing design and have engines mounted at the aft end of the fuselage  12 . Like any aircraft, the size and performance of business jets vary with the function for which the aircraft has been designed. Aircraft are available that vary in gross weight from about 11,000 to 65,000 pounds. Cruising speeds lie in the range from 0.7 to 0.85 Mach number. Ranges vary from intercontinental values to as low as 1150 miles. Many of the new aircraft being produced have at least nonstop transcontinental capability. The number of passengers that can be accommodated, even on aircraft of the same design, varies widely depending on the interior cabin arrangements; for example, aircraft can be found with the capability of carrying from 5 to 19 passengers. 
     The small size of many business jets imposes certain design constraints not encountered in large transport aircraft. One dimension that cannot be scaled as the size of an aircraft is reduced is the size of the human body that occupies the cabin. This essentially invariant dimension is usually a predominant factor in determining the fuselage diameter. A small fuselage diameter is desirable to reduce weight and maintain as low a value of the ratio of wetted area to wing area as possible. Accordingly, only very large business jets have a cabin diameter sufficiently large to accommodate a person standing in an upright position. A cabin free of obstructions is a desirable feature intended to improve passenger comfort while also reducing the possibility of a passenger tripping or falling. 
     With this in mind, the passenger platform  14  of the aircraft  10  is generally formed with the center aisle  16  sunken to take full advantage of the fuselage diameter while the passenger is standing. Similarly, the elevated positioning of the seating area  18  substantially along the horizontal diameter of the fuselage  12  takes full advantage of the fuselage diameter while the passengers are seated. 
     Manufacturers generally desire to limit modifications to the passenger compartment  20  to only required modifications. As such, the present invention takes advantage of the unused space beneath the center aisle  16  by positioning a subwoofer assembly  22  under the passenger platform  14  at the center aisle  16  and porting the sound through the recessed sidewalls  25  linking the seating area  18  with the center aisle  16 . 
     With particular reference to FIGS. 2,  3  and  4 , the subwoofer assembly  22  in accordance with the present invention is disclosed. The subwoofer assembly  22  includes a subwoofer housing  24  shaped and dimensioned to fit beneath the center aisle  16  of the passenger platform  14  formed within an aircraft fuselage  12  (see FIGS.  1  and  2 ). Specifically, the subwoofer housing  24  is shaped and dimensioned to fit beneath the center aisle  16  of the passenger platform  14 . The subwoofer housing  24  is preferably made of lightweight materials. For example, the housing  24  is preferably made from aluminum, although other materials may be employed without departing from the spirit of the present invention. 
     The subwoofer housing  24  includes a front wall  26  and a rear wall  28  connected by first and second lateral sidewalls  30 ,  32 , a top sidewall  34  and a bottom sidewall  36 . Sound generated by the subwoofer assembly  22  is directed from the subwoofer housing  24  through a sound port  38  formed in the front wall  26  of the subwoofer housing  24 . The sound port  38  of the present subwoofer housing  24  is substantially oval shaped, although other shapes may be employed without departing from the spirit of the present invention. 
     The internal structure of the subwoofer assembly  22  is composed of a low frequency driver  40  mounted on a sound baffle  42  extending from the top sidewall  34 /rear wall  28  to the bottom sidewall  36 /front wall  26  within the subwoofer housing  24 . The sound generated by the subwoofer assembly  22  is enhanced by the provision of an angled sound baffle  42  within the subwoofer housing  24 . The sound baffle  42  is angled as it extends from the top sidewall  34 /rear wall  28  of the subwoofer housing  24  to the bottom sidewall  36 /front wall  26  of the subwoofer housing  24  to create a sound space which expands as the sound baffle  42  extends from the top sidewall  34  of the subwoofer housing  24  to the bottom sidewall  36  of the subwoofer housing  24 . The sound baffle  42  controls transmission of sound from the driver to the sound port  38  in a manner optimizing the generated sound. 
     Specifically, the sound baffle  42  includes a first baffle section  44  extending from the top sidewall  34 /rear wall  28  of the subwoofer housing  24  to a central section of the subwoofer housing  24 . The driver  40  is mounted within an opening  46  formed in the first baffle section  44  of the sound baffle  42 . The driver  40  preferably works in a standard subwoofer frequency range, although drivers functioning in different ranges may be used without departing from the spirit of the invention. The driver  40  includes standard sound source connections and may include crossover circuitry if so desired for the final sound system configuration. 
     The sound space created by the first baffle section  44 , that is, the space between the first baffle section  44  and the top sidewall  34  of the subwoofer housing increases as the first baffle section  44  extends from the top sidewall  34  of the subwoofer housing  24  toward the central section of the subwoofer housing  24 . A second baffle section  48  couples the first baffle section  46  to a third baffle section  50 , which extends from the central section to the bottom sidewall  36 /front wall  26  of the subwoofer housing  24 . 
     The second baffle section  48  extends away from the top sidewall  34  and rear wall  28  of the subwoofer housing  34 , and increases the spacing between the top sidewall  34  of the subwoofer housing  34  and the third baffle section  50 . As with the first baffle section  44 , the sound space created by the third baffle section  50  and the top sidewall  34  of subwoofer housing  24  increases as the third baffle section  50  extends from the central section of the subwoofer housing  24  toward the bottom sidewall  36  of the subwoofer housing  24 . 
     As shown in FIGS. 1 and 2, and as briefly discussed above, the subwoofer assembly  22  is mounted under the center aisle  16  within the aircraft fuselage  12 . Specifically, the subwoofer housing  24  is bolted to existing support structures  52  located beneath the center aisle  16 . A sound tube  54  links the sound port  38  to an opening  56  formed in the sidewall  25  linking the center aisle  16  to the seating area  18 . The proximal end  58  of the sound tube  54  is shaped and dimensioned to telescopically receive the sound port  38  of the subwoofer housing  24 . Once the sound tube  54  is properly position on the sound port  38 , a clamp  60  is secured about the sound tube  54  and tightened to frictionally couple the sound tube  54  to the sound port  38  in a desired manner. The efficiency of this positioning allows the subwoofer assembly  22  to be incorporated within an aircraft  10  without compromising the interior design of the passenger compartment  20 . 
     This two-piece construction improves installation by permitting stepwise installation without the necessity of installing the entire assembly in a single piece. In addition, the adjustable telescoping coupling utilized in connecting the sound tube  54  to the sound port  38  permits the present subwoofer assembly  22  to be readily adapted for positioning at various locations along center aisle  16  (i.e., where the distance the sound tube must extend to reach a sidewall varies) and within differing aircraft. 
     Generally, the subwoofer assembly  22  is mounted such that the sound port in the sidewall extends along the center aisle under the passenger support. The sound tube  54  couples the sound port  38  to the passenger compartment  20  of the aircraft  10 . Specifically, the proximal end  58  of the sound tube  54  is coupled to the sound port  38  of the subwoofer housing  24  and the distal end  62  of the sound tube  54  is coupled adjacent the opening  56  in the wall  25  to direct sound to the passenger compartment  20  of the aircraft  10 . 
     The distal end  62  of the sound tube  54  is mounted flush with the conforming opening  56  formed in the wall  25  linking the center aisle  16  to the seating area  18  within the passenger compartment  20  to direct sound therein. The distal end  62  of the sound tube  54  may be covered to conform to the interior decor of the aircraft  10  and hide the port through which the sound enters the passenger compartment of the aircraft. 
     An alternate embodiment of the present invention is disclosed in FIGS. 5,  6  and  7 . As with the embodiment previously described, this embodiment is adapted for placement within the unused space beneath the center aisle  116 ; that is, the subwoofer assembly  110  is positioned under the passenger platform  114  at the center aisle  116  and ports the sound through the recessed sidewalls  125  linking the seating area with the center aisle  116 . 
     With particular reference to FIG. 5, the subwoofer assembly  110  in accordance with the present invention is disclosed. The subwoofer assembly  110  includes a subwoofer housing  120  shaped and dimensioned to fit beneath the center aisle  116  of the passenger platform  114  formed within an aircraft fuselage. The subwoofer housing  120  is preferably made of lightweight materials. For example, the housing  120  is preferably made from aluminum, although other materials may be employed without departing from the spirit of the present invention. 
     The subwoofer housing  120  includes a front wall  122  and a rear wall  124  connected by first and second lateral sidewalls  126 ,  128 , a top sidewall  130  and a bottom sidewall  132 . A low frequency driver  134  is mounted to the top sidewall  130  with the cone  136  of the driver  134  directed through an opening in the top sidewall  130  away from the housing  120 . A cover plate  138  is positioned over the cone  136  and substantially encloses the cone  136 . However, sound generated by the driver is passed from within the cover plate  138  through a sound port  140  formed in the sidewall of the coverplate  138 . While a preferred embodiment of the present invention provides a substantially empty subwoofer housing, various baffles and acoustic elements may be positioned within the internal structure of the subwoofer housing without departing from the spirit of the present invention. 
     A sound tube  142  couples the sound port  140  of the subwoofer assembly  110  to the passenger compartment of an aircraft. Specifically, and with reference to FIG. 5, the subwoofer assembly  110  is mounted under the center aisle  116  within the aircraft fuselage. The subwoofer housing  110  is bolted to existing support structures located beneath the center aisle  116 . The sound tube  142  links the sound port  140  to an opening  144  formed in the sidewall  125 , linking the center aisle  116  to the seating area  118 . The proximal end  146  of the sound tube  142  is shaped and dimensioned to be telescopically received within the sound port  140  of the cover plate  138 . Once the sound tube  142  is properly position within the sound port  140 , a frictional grommet (not shown) is positioned between the sound port  140  and the sound tube  142 . The grommet holds the sound tube  142  relative to the subwoofer housing  120  while also sealing the space between the sound port  140  and the sound tube  142 . The efficiency of this positioning allows the subwoofer assembly  110  to be incorporated within an aircraft without compromising the interior design of the passenger compartment. 
     Generally, the subwoofer assembly  110  is mounted such that the sound tube  142  extends along the center aisle  116  under the passenger support  114 . The sound tube  142  couples the sound port  140  to the passenger compartment of the aircraft. Specifically, the distal end  148  of the sound tube  142  is coupled adjacent the opening  144  in the wall  125  to direct sound to the passenger compartment of the aircraft. 
     The distal end  148  of the sound tube  142  is mounted flush with the conforming opening  144  formed in the wall  125 , linking the center aisle  116  to the seating area  118  within the passenger compartment to direct sound therein. The distal end  148  of the sound tube  142  may be covered to conform to the interior decor of the aircraft and hide the port through which the sound enters the passenger compartment of the aircraft. 
     By porting the sound generated by the subwoofer assembly in the manner discussed above, the sound may enter the passenger compartment at any convenient location. The interior decor need not be altered to suit the positioning of the subwoofer assembly. As such, the interior remains intact, maintaining the noise insulation and structural stability provided by the interior panels. 
     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. 
     It is further contemplated that the exact shape of the subwoofer assembly may be varied to suit specific needs. For example, the unit could be wider than tall where the fuselage construction dictates such a design. 
     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, is intended to cover all modifications and alternate constructions falling within the spirit and scope of the invention as defined in the appended claims.