Patent Publication Number: US-11647316-B2

Title: Near to the ear subwoofer

Description:
CROSS-REFERENCED TO RELATED APPLICATIONS 
     This application is a continuation of U.S. patent application Ser. No. 17/156,840, filed on Jan. 25, 2021, which is currently under allowance, which claims benefit of U.S. Provisional Application No. 62/963,793 filed on Jan. 21, 2020, the disclosure of which are hereby incorporated by reference in their entirety for all purposes. 
    
    
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to an audio system in a motor vehicle. 
     2. Description of the Related Art 
     The nature of vehicle acoustics produces compromised performance in even the most carefully designed sound systems. Efforts to create a smooth, impactful audio performance for vehicle occupants are negatively influenced by size, placement, and transfer characteristics between the speakers and the occupants in this complex space. 
     A drawback of known audio systems is that the output of a speaker can be optimized for only one location creating sub-optimal conditions at other listening locations served by common loudspeakers. 
     Studies have shown that placing speakers near the occupant&#39;s ear can overcome the effects of location, but this creates additional problems. The existence of physically large speakers near the occupant&#39;s head can be unsafe for reasons of visibility and crash safety. 
     Active noise cancellation (ANC) is an important feature of modern audio systems, wherein the same speakers used for sound reproduction are also utilized for cabin noise compensation. ANC is typically implemented by using door speakers originating 18 to 48 inches away from the listener&#39;s ears or from a subwoofer located as far as 100 inches away. These long distances create inherent timing issues and suboptimal acoustic transfer characteristics that are difficult to overcome. Additionally, these typical ANC implementations rely on high acoustic output to achieve an appropriate sound level to cancel noise at the listener&#39;s ear. The acoustic output of such systems is typically high enough to induce modal excitation in the acoustic space of the vehicle cabin, thus making effective noise cancellation more difficult. 
     Prior art inventions use small headrest loudspeakers. Due to their small size, these lack the extended low frequency needed for both performance audio and active noise cancellation. The typical workaround is to use the larger existing door speakers to supplement the frequency response of the small headrest speakers to reproduce the necessary bass in the desired personal location, and to use DSP processing to cancel the resultant bass at other listening locations. Not only is this quite complicated as a result of the multiple path length variations from speakers to occupants, but it is prone to inaccuracy and instability as a compromise. Therefore, the need for rendering low frequency content specific and exclusive to each seat creates a key requirement to more precisely place said low frequency content in the vicinity of the occupant&#39;s head. 
     SUMMARY OF THE INVENTION 
     The invention comprises, in one form thereof, a loudspeaker arrangement for a motor vehicle with the arrangement comprising of: a seat enhanced with one or more localized sound output ports for low frequency sound reproduction; a housing, such as an enclosure substantially surrounding a loudspeaker such that sound from the loudspeaker is emitted directly into the interior of the enclosure; and one or more audio transmission line channels acoustically interconnecting the interior of the enclosure to the one or more sound output ports. The enclosure should be situated below, behind, or in some fixed location around or within the seat at some distance away from the output ports. The location of the sound outputs ports should be situated at or near a seat headrest, such that the output ports are substantially less than a wavelength of sound at the highest operating frequency from either ear of the seat&#39;s occupant. In the preferred embodiment, the invention uses the acoustic response and resonances of the 1) rear enclosure, 2) the front vented enclosure, 3) loudspeaker parameters, and 4) audio transmission path from the enclosure to the output ports. 
     The invention comprises, in another form thereof, a loudspeaker arrangement with a similar configuration as described in the preferred embodiment in [0007], except that two loudspeakers are used in place of one. This includes configurations such as push-pull, isobaric, mono, or stereo combinations of two loudspeakers utilized in coherent or non-coherent summation. 
     The invention comprises, in another form thereof, a loudspeaker arrangement with a similar configuration as described in the preferred embodiment in the immediately preceding paragraph, except that two discrete units are used in a stereo configuration. 
     The invention comprises, in another form thereof, a method for providing audio infotainment in a motor vehicle, involving the use of any of the aforementioned forms. 
     The invention delivers high output, low distortion bass close to the listener&#39;s ears to minimize the excitation of the acoustic space of the vehicle&#39;s cabin. Thus the negative, variable impact of the vehicle&#39;s acoustics upon the occupant&#39;s listening experience is reduced. 
     The invention may enable one individual listener to enjoy a personal choice of music, speech, or phone conversation with the least amount of acoustic disturbance to other passengers. This is achieved primarily by the close acoustic proximity to the listener&#39;s ears of the acoustic output of the invention. 
     This invention may be optimized for each individual listening location (e.g., each single occupant seat). 
     The speaker enclosure is mounted away from the occupant&#39;s head which allows for greater safety and provides a more flexible use of alternate space. 
     Because the output of the device is in the vehicle seat, when the seat is moved backward or forward for the comfort of the occupant, the output of the invention stays consistent since the output moves with the occupant&#39;s seat (and ears). 
     The invention may also use digital signal processing (DSP) to equalize and compensate for signals from other speakers that are farther away. 
     The invention may accomplish active noise cancellation with smaller distances between the speakers and the listener, and without the significant drawbacks of the conventional technology used today. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The above-mentioned and other features and objects of this invention, and the manner of attaining them, will become more apparent and the invention itself will be better understood by reference to the following description of embodiments of the invention taken in conjunction with the accompanying drawings, wherein: 
         FIG.  1    is a schematic diagram of one embodiment of a vehicle loudspeaker arrangement of the present invention. 
         FIG.  2    is a schematic diagram of another embodiment of a vehicle loudspeaker arrangement of the present invention. 
         FIG.  3 A  is a schematic view of the loudspeaker apparatus of  FIG.  2    along line  3 A- 3 A. 
         FIG.  3 B  is a schematic side view of another embodiment of a loudspeaker apparatus of the present invention. 
         FIG.  3 C  is a schematic side view of yet another embodiment of a loudspeaker apparatus of the present invention. 
         FIG.  3 D  is a schematic side view of still another embodiment of a loudspeaker apparatus of the present invention. 
         FIG.  3 E  is a schematic side view of a further embodiment of a loudspeaker apparatus of the present invention. 
         FIG.  4    is a flow chart of one embodiment of a method of the invention for providing audio infotainment in a motor vehicle. 
     
    
    
     DETAILED DESCRIPTION 
     The embodiments hereinafter disclosed are not intended to be exhaustive or limit the invention to the precise forms disclosed in the following description. Rather the embodiments are chosen and described so that others skilled in the art may utilize its teachings. 
       FIG.  1    illustrates one embodiment of a vehicle loudspeaker arrangement  10  of the present invention including a rear view of a passenger seat  12 . A loudspeaker apparatus  14  is disposed below seat  12  and includes a loudspeaker component in the form of a woofer  16 , a rear sealed enclosure  18 , and a front vented enclosure  20 . Enclosures  18 ,  20 , and possibly a floor of the vehicle, may conjunctively form an enclosure around and surrounding woofer  16 . 
     Audio transmission line vents  22   a - b  provide enclosed air conduits or pathways interconnecting an interior of apparatus  14  with respective sound outputs  24   a - b  at a top end  26  of a backrest  28  of seat  12 . A headrest  30  is disposed between sound outputs  24   a - b . Sound output  24   a  is close (e.g., 4 to 6 inches away) to the left ear of a passenger sitting in seat  12 , and sound output  24   b  is close (e.g., 4 to 6 inches away) to the right ear of a passenger sitting in seat  12 . 
     During use, transmission line vents  22   a - b  may carry sound produced by woofer  16  to sound outputs  24   a - b  with as little change and/or distortion as possible. It is also possible for the change in sound and/or distortion due to transmission line vents  22   a - b  to not be minimized, but rather to be taken into account in the audio signal that is transmitted to woofer  16 . 
     The enclosure around woofer  16  and transmission line vents  22   a - b  may be soundproof to the extent that the sound from woofer  16  may be heard only through sound outputs  24   a - b.    
       FIG.  2    illustrates another embodiment of a vehicle loudspeaker arrangement  210  of the present invention including a rear view of a passenger seat  212 . A loudspeaker apparatus  214  is disposed below seat  212  and includes a loudspeaker component in the form of a woofer  216 , an optional rear sealed enclosure  218 , and a front vented enclosure  220 . Enclosures  218 ,  220 , and possibly a floor of the vehicle, may conjunctively form an enclosure around and surrounding woofer  216 . 
     Audio transmission line vent  222  provides an enclosed air conduit or pathway interconnecting an interior of apparatus  214  with a sound output  224  at a top end  226  of a backrest  228  of seat  212 . A headrest  230  is disposed adjacent to sound output  224 . Sound output  224  may be close (e.g., 4 to 6 inches away) to the left ear of a passenger sitting in seat  212 . 
     During use, transmission line vent  222  may carry sound produced by woofer  216  to sound output  224  with as little change and/or distortion as possible. It is also possible for the change in sound and/or distortion due to transmission line vent  222  to not be minimized, but rather to be taken into account in the audio signal that is transmitted to woofer  216 . 
     The enclosure around woofer  216  and transmission line vent  222  may be soundproof to the extent that the sound from woofer  216  may be heard only through sound output  224 . 
       FIG.  3 A  illustrates loudspeaker apparatus  214  of  FIG.  2    along line  3 A- 3 A. The enclosure is sealed, and the sound propagates up vent  222  in direction  232 . 
       FIG.  3 B  illustrates another embodiment of a loudspeaker apparatus  314  of the present invention including a woofer  316 , a rear vented enclosure  318 , and a front vented enclosure  320 . Enclosures  318 ,  320 , and possibly a floor of the vehicle, may conjunctively form an enclosure around and surrounding woofer  316 . The sound propagates up vent  322  in direction  332 . A transmission line vent  334  may provide an air pathway between an interior of enclosure  318  and ambient air for tuning purposes. 
       FIG.  3 C  illustrates yet another embodiment of a loudspeaker apparatus  414  of the present invention. Apparatus  414  is substantially similar to apparatus  214  except that apparatus  414  does not include a rear enclosure, but rather is open. Another difference is that woofer  416  faces in the opposite direction as woofer  216 , which is arbitrary because woofers  216 ,  416  both emit sound in two opposite lateral directions (e.g., the facing direction and the direction opposite to the facing direction) substantially equally. The sound propagates up vent  422  in direction  432 . 
       FIG.  3 D  illustrates still another embodiment of a loudspeaker apparatus  514  of the present invention. Apparatus  514  is substantially similar to apparatus  414  except that, instead of being open, apparatus  514  may be attached to, and may emit sound directly into, a vehicle frame  536 . Apparatus  514  may be attached to frame  536  during a “body in white” (BIW) stage of vehicle assembly. The sound also propagates up vent  522  from woofer  516 . 
       FIG.  3 E  illustrates a further embodiment of a loudspeaker apparatus  614  of the present invention. Apparatus  614  is substantially similar to apparatus  314  except that enclosures  618 ,  620  are fluidly interconnected by an air pathway provided by a transmission line vent  638  to achieve double tuning. 
       FIG.  4    illustrates one embodiment of a method  400  of the invention for providing audio infotainment in a motor vehicle. Although a particular order of steps is illustrated, the embodiment of the invention is not limited to the steps being in any particular time sequential order. In a first step  402 , a seat including two sound outputs is provided. For example, seat  12  includes sound outputs  24   a - b.    
     In a next step  404 , the seat is used to support a human passenger of the motor vehicle such that each of the sound outputs is less than twelve inches from a respective one of two ears of the passenger. For example, when a human passenger sits in seat  12 , sound output  24   a  is 4 to 6 inches away from the left ear of the passenger, and sound output  24   b  is 4 to 6 inches away from the right ear of the passenger. 
     Next, in step  406 , a woofer is installed below the seat. For example, woofer  16  may be installed below seat  12 . 
     In step  408 , sound is emitted from the woofer directly into an interior of an enclosure that substantially surrounds the woofer. For example, sound may be emitted from woofer  16  directly into an interior of an enclosure that is defined by enclosures  18 ,  20 , and a floor of the vehicle. The enclosure may substantially surround woofer  16 . 
     In a final step  410 , the interior of the enclosure is audially interconnected with each of the two sound outputs. For example, the interior of the enclosure defined by enclosures  18 ,  20 , and a floor of the vehicle may be audially interconnected with each of two sound outputs  24   a - b  by audio transmission line vents  22   a - b.    
     While this invention has been described as having an exemplary design, the present invention may be further modified within the spirit and scope of this disclosure. This application is therefore intended to cover any variations, uses, or adaptations of the invention using its general principles. Further, this application is intended to cover such departures from the present disclosure as come within known or customary practice in the art to which this invention pertains.