Low profile loudspeaker device

Abstract

A loudspeaker device includes first and second diaphragms arranged co-axially in an opposed relation to each other and having a rear volume in-between, each diaphragm having a plurality of motors operatively coupled thereto, and a frame having first and second ends, and first and second rims provided at the first and second ends, respectively. The motors of the first and second diaphragms are arranged in the same plane, and the motors are provided on the frame around the periphery of the first and second diaphragms.

1 . A device, comprising:
 a frame having a first end portion axially opposite a second end portion;   a first membrane attached to the first end portion of the frame;   a second membrane attached to the second end portion of the frame, wherein the first and second membranes define a volume therebetween, the volume having a periphery; and   a plurality of motors arranged at the periphery of the volume, wherein the plurality of motors is arranged in an alternating manner such that adjacent motors are operably coupled to different membranes.   
     
     
         2 . The device of  claim 1 , further comprising:
 a first surround attaching the first membrane to the first end portion of the frame; and   a second surround attaching the second membrane to the second end portion of the frame,   wherein each motor of the plurality of motors at least partially radially overlaps both of (i) the first surround and (ii) the second surround.   
     
     
         3 . The device of  claim 1 , wherein the frame comprises first and second rims surrounding the first and second membranes, respectively, and wherein the plurality of motors radially overlaps both of (i) the first rim and (ii) the second rim. 
     
     
         4 . The device of  claim 3 , wherein the frame comprises a plurality of posts extending axially from the first rim toward the second rim, and wherein each of the plurality of posts carries a corresponding motor of the plurality of motors. 
     
     
         5 . The device of  claim 1 , wherein the plurality of motors comprises (i) a first set of motors operably coupled to the first membrane and (ii) a second set of motors operably coupled to the second membrane, and wherein the first set of motors axially overlaps the second set of motors. 
     
     
         6 . The device of  claim 5 , wherein the first set of motors is axially spaced apart from the second end portion of the frame by a first distance, wherein the second set of motors is axially spaced apart from the first end portion of the frame by a second distance, and wherein the first set of motors axially overlaps the second set of motors over an axial distance that is greater than the first distance or the second distance. 
     
     
         7 . The device of  claim 6 , wherein the first and second end portions of the frame are separated axially by a third distance, and wherein the first distance or the second distance is less than or equal to about 20 percent of the third distance. 
     
     
         8 . The device of  claim 5 , wherein the second set of motors is arranged radially perpendicular to the first set of motors. 
     
     
         9 . The device of  claim 1 , wherein the first and second membranes have a circular shape. 
     
     
         10 . The device of  claim 1 , wherein the first and second membranes have a rectangular shape. 
     
     
         11 . The device of  claim 1 , wherein the volume separates the first and second membranes by a separation distance, and wherein a maximum excursion distance of the first membrane is substantially equal to ¼ of the separation distance. 
     
     
         12 . A compact loudspeaker, comprising:
 a frame having a first end portion axially spaced apart from a second end portion;   a first diaphragm attached to the first end portion of the frame;   a second diaphragm attached to the second end portion of the frame, wherein the first and second diaphragm define an intermediate portion therebetween, the intermediate portion having a periphery; and   a plurality of motors arranged at the periphery of the intermediate portion, wherein the plurality of motors is arranged in an alternating manner such that adjacent motors are operably coupled to different diaphragms.   
     
     
         13 . The compact loudspeaker of  claim 12 , further comprising:
 a first surround attaching the first diaphragm to the first end portion of the frame; and   a second surround attaching the second diaphragm to the second end portion of the frame,   wherein each motor of the plurality of motors at least partially radially overlaps both of (i) the first surround and (ii) the second surround.   
     
     
         14 . The compact loudspeaker of  claim 12 , wherein the frame comprises first and second rims surrounding the first and second diaphragms, respectively, and wherein the plurality of motors radially overlaps both of (i) the first rim and (ii) the second rim. 
     
     
         15 . The compact loudspeaker of  claim 14 , wherein the frame comprises a plurality of posts extending axially from the first rim toward the second rim, and wherein each of the plurality of posts carries a corresponding motor of the plurality of motors. 
     
     
         16 . The compact loudspeaker of  claim 12 , wherein the plurality of motors comprises (i) a first set of motors operably coupled to the first diaphragm and (ii) a second set of motors operably coupled to the second diaphragm, and wherein the first set of motors axially overlaps the second set of motors. 
     
     
         17 . The compact loudspeaker of  claim 16 , wherein the second set of motors is arranged radially perpendicular to the first set of motors. 
     
     
         18 . A device having a transducer, the transducer comprising:
 a first end portion, a second end portion, and an intermediate portion therebetween;   a first membrane attached to the first end portion;   a second membrane attached to the second end portion, wherein the first and second membranes comprise respective first and second outer edge portions that are aligned with an outer portion of the intermediate portion; and   a plurality of motors arranged at the outer portion of the intermediate portion, wherein the plurality of motors is arranged in an alternating manner such that adjacent motors are operably coupled to different membranes.   
     
     
         19 . The device of  claim 18 , wherein the transducer comprises:
 a first surround attaching the first membrane to the first end portion, and   a second surround attaching the second membrane to the second end portion,   wherein each motor of the plurality of motors at least partially radially overlaps both of (i) the first surround and (ii) the second surround.   
     
     
         20 . The device of  claim 18 , wherein the transducer comprises first and second rims surrounding the first and second membranes, respectively, and wherein the plurality of motors radially overlaps both of (i) the first rim and (ii) the second rim. 
     
     
         21 . The device of  claim 20 , wherein the transducer comprises a plurality of posts extending axially from the first rim toward the second rim, and wherein each of the plurality of posts carries a corresponding motor of the plurality of motors. 
     
     
         22 . The device of  claim 18 , wherein the plurality of motors comprises (i) a first set of motors operably coupled to the first membrane and (ii) a second set of motors operably coupled to the second membrane, and wherein the first set of motors axially overlaps the second set of motors. 
     
     
         23 . The device of  claim 22 , wherein the second set of motors is arranged radially perpendicular to the first set of motors. 
     
     
         24 . An audio transducer, comprising:
 a frame having a first end portion axially spaced apart from a second end portion;   a first diaphragm attached to the first end portion of the frame;   a second diaphragm attached to the second end portion of the frame, wherein the first and second diaphragm define an intermediate portion therebetween, the intermediate portion having a periphery; and   a plurality of motors arranged at the periphery of the intermediate portion, wherein the plurality of motors is arranged in an alternating manner such that adjacent motors are operably coupled to different diaphragms.   
     
     
         25 . The audio transducer of  claim 24 , further comprising:
 a first surround attaching the first diaphragm to the first end portion of the frame; and   a second surround attaching the second diaphragm to the second end portion of the frame,   wherein each motor of the plurality of motors at least partially radially overlaps both of (i) the first surround and (ii) the second surround.   
     
     
         26 . The audio transducer of  claim 24 , wherein the frame comprises first and second rims surrounding the first and second diaphragms, respectively, and wherein the plurality of motors radially overlaps both of (i) the first rim and (ii) the second rim. 
     
     
         27 . The audio transducer of  claim 26 , wherein the frame comprises a plurality of posts extending axially from the first rim toward the second rim, and wherein each of the plurality of posts carries a corresponding motor of the plurality of motors. 
     
     
         28 . The audio transducer of  claim 24 , wherein the plurality of motors comprises (i) a first set of motors operably coupled to the first diaphragm and (ii) a second set of motors operably coupled to the second diaphragm, and wherein the first set of motors axially overlaps the second set of motors. 
     
     
         29 . The audio transducer of  claim 28 , wherein the first set of motors is axially spaced apart from the second end portion of the frame by a first distance, wherein the second set of motors is axially spaced apart from the first end portion of the frame by a second distance, and wherein the first set of motors axially overlaps the second set of motors over an axial distance that is greater than the first distance or the second distance. 
     
     
         30 . The audio transducer of  claim 29 , wherein the first and second end portions of the frame are separated axially by a third distance, and wherein the first distance or the second distance is less than or equal to about 20 percent of the third distance.