Abstract:
A drum comprising a hollow drum shell having opposite ends and first and second drumheads closing said opposite ends. At least one air vent opening is provided through the drum head for acoustic venting, such that at least one air vent opening is located at a position distanced from at least one of said opposite end by a preset distance range of distances calculated by using the Golden Ratio and an acceptable margin or range of variation therefrom.

Description:
[0001]    This application is a nonprovisional patent application based on U.S. Provisional Patent Application No. 60/880,005 filed Jan. 12, 2007 and is hereby incorporated by reference. 
     
    
     BACKGROUND OF THE INVENTION 
       [0002]    1. Field of the Invention 
         [0003]    The present invention relates to percussion instruments in general and more particularly to an acoustic drum having at least one acoustic air vent hole. 
         [0004]    2. Description of Related Art 
         [0005]    When a drum is struck, the drumhead is depressed inwardly and forces a column of air down the length of the drum and causes the drumhead on the opposite side to balloon outwardly. If the drum is air tight, the top and bottom heads will oscillate for a relatively long time as the air within the drum oscillates back and forth and feeds energy to the heads to keep the oscillation going. Long oscillation time produces a long sustain which is desirable at slow tempos; however, at faster tempos the oscillation can hamper performance. 
         [0006]    For example, oscillation of a drum is analogous to oscillation of a trampoline. If one times his/her jumps to the oscillation of the trampoline, the trampoline will help the jumper maintain a rhythm. However, if one&#39;s timing if off, the trampoline will stop. An analogous event happens when one plays a drum. For example, if one plays a drum in phase with the moving drumhead the playing action will feel normal but when one get out of phase with the drumhead, which is very easy to do especially when playing fast and/or when playing intricate patterns, the drumhead can randomly feel dead and stifle rebound and negatively impact your performance. 
         [0007]    Air vents allow the air to escape from the drum and return the heads to their resting state quickly thus providing an essentially flat and predictable playing surface on which to play for improved confidence, speed, and intricacy. 
         [0008]    Companies typically choose the air vent locations for drums based on cosmetics considerations instead of science or sound. Some attempts have been made to attenuate the movement of air through vent holes by adjusting the size of the vent hole or by using an adjustable valve on the vent hole. However, no prior art is known to exist that enhances drum performance based on air vent location. 
       SUMMARY OF THE INVENTION 
       [0009]    A drum is provided that comprises a hollow drum shell having opposite ends and first and second drumheads closing said opposite ends. At least one air vent opening is provided through the drum shell for acoustic venting. In accordance with this invention, the air vent opening(s) is/are located at a position distanced from at least one of said opposite end by a preset distance range of distances calculated by using the Golden Ratio and an acceptable margin or range of variation therefrom. 
         [0010]    In accordance with one application of the invention, at least two acoustic vent holes are formed in the drum shell. The location of both the vent holes is determined by the “Golden Ratio”. The location of the first “bottom” vent hole is defined by the lower “Golden Ratio”, while the location of the second “attack” vent hole is defined by the upper “Golden Ratio”. A plug can be provided to selectively plug the upper or lower acoustic vent holes depending on the desired sound. Thus, a user can have more “attack” by plugging the bottom air vent or more “depth” by plugging the upper air vent. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0011]    Other objects and advantages of the invention will become apparent from a study of the following specification when viewed in light of the accompanying drawings, wherein: 
           [0012]      FIG. 1  is a perspective view of an acoustic drum in accordance with a first exemplary embodiment of the present invention; 
           [0013]      FIG. 2  is a schematic view of an acoustic drum shell in accordance with the first exemplary embodiment of the present invention; 
           [0014]      FIG. 3  is a schematic view of an acoustic drum shell in accordance with a second exemplary embodiment of the present invention; 
           [0015]      FIG. 4  is a schematic view of an acoustic drum shell in accordance with a third exemplary embodiment of the present invention; 
           [0016]      FIG. 5  shows exemplary air vent positions (hole centers) from a lower bearing edge of an acoustic drum by using the Golden Ratio. 
       
    
    
     DESCRIPTION OF PREFERRED EMBODIMENTS 
       [0017]      FIGS. 1 and 2  of the drawings illustrate in detail a first exemplary embodiment of an acoustic drum  10   1  in accordance with the present invention. As illustrated in  FIG. 1 , the acoustic drum  10   1  comprises a substantially cylindrical drum shell  12   1  having an upper (top) bearing edge  14  and a lower (bottom) bearing edge  16 . The acoustic drum  10   1  further comprises upper (top) and lower (bottom) drumheads  18  and  20 , respectively, mounted to opposite ends of the drum shell  12   1 . According to the first exemplary embodiment of the present invention, the drum shell  12   1  is provided with an acoustic vent in the form of an acoustic vent hole  22   1 . 
         [0018]    When the acoustic drum  10   1  is struck, a membrane of the drumhead, such as the membrane  19  of the upper drumhead  18 , is depressed inwardly and forces a column of air down the length of the acoustic drum  10   1  and causes the drumhead on the opposite side, such as the lower drumhead  20 , to balloon outwardly. If the drum is air tight, the top and bottom heads will oscillate for a relatively long time as the air within the drum oscillates back and forth and feeds energy to the heads to keep the oscillation going. Long oscillation time produces a long sustain which is desirable at slow tempos; however, at faster tempos the oscillation can hamper performance. 
         [0019]    The acoustic vent hole  22   1  allows the air to escape from the drum  10   1  and return the drumheads  18  and  20  to their resting state quickly, thus providing an essentially flat and predictable playing surface on which to play for improved confidence, speed, and intricacy. 
         [0020]    Most companies put the air vent in locations on the drum based on cosmetics consideration rather than scientific or acoustic considerations. 
         [0021]    According to the present invention, location of the acoustic vent hole in the direction of the length (or depth) of the acoustic drum is defined by the “Golden Ratio” because the location defined by the Golden Ratio has been proven by the instant inventors to be the optimal location for the vent hole(s) to maximize the functional and tonal qualities of the drum. As will be described below, the best sound qualities are achieved for both an “attack” sound or a “bottom” sound when the location of the vent hole(s) are dictated by the “Golden Ratio.” 
         [0022]    The “Golden Ratio”, usually denoted φ, expresses the relationship that the sum of two quantities is to the larger quantity as the larger is to the smaller. The golden ratio is the following algebraic irrational number with its numerical approximation: 
         [0000]    
       
         
           
             ϕ 
             = 
             
               
                 
                   1 
                   + 
                   
                     5 
                   
                 
                 2 
               
               ≈ 
               
                 1.618033989 
                 . 
               
             
           
         
       
     
         [0023]    Algebraically the “Golden Ratio” is expressed as following: 
         [0000]    
       
         
           
             
               
                 a 
                 + 
                 b 
               
               a 
             
             = 
             
               
                 a 
                 b 
               
               = 
               
                 ϕ 
                 . 
               
             
           
         
       
     
         [0024]    According to the first exemplary embodiment of the present invention, the acoustic vent hole  22   1  is positioned in the lower “Golden Ratio” location (closer to the bottom drumhead  20  of the drum  10   1 ). As illustrated in detail  FIG. 2 , a centerline  23   1  of the vent hole  22   1  is spaced from the top edge  14  of the drum shell  12   1  to a length D U1 , and from the bottom edge  16  thereof to a length D L1 . According to the first exemplary embodiment of the present invention, a ratio of the length D U1  to the length D L1  substantially equals to the “Golden Ratio”, i.e. 1.618033989. With the air vent hole in the lower “Golden Ratio” location (closer to the bottom head of the drum), more sustain and a fuller, deeper sound can be heard. This is advantageous for the player who wants a more melodious sound. It is noted that the location of the vent hole  22   1  may be located within a range of tolerance or deviation of about 10% from the exact location determined by the “Golden Ratio.” 
         [0025]    Further, according to the first exemplary embodiment of the present invention, the acoustic drum  10   1  could be turned upside down to achieve more “attack”, or “aggressive”, sound. 
         [0026]      FIG. 3  of the drawings illustrates a second exemplary embodiment of an acoustic drum  10   2  in accordance with the present invention. The acoustic drum  10   2  of the second exemplary embodiment is substantially similar to the acoustic drum  10   1  of the first exemplary embodiment and differs by location of an acoustic vent hole  22   2  formed in a drum shell  12   2 . In  FIG. 3 , a length D U2  defines a distance between a centerline  23   2  of the vent hole  22   2  to the top edge  14  of the drum shell  12   2 , while a length D L2  defines a distance between the centerline  23   2  of the vent hole  22   2  to the bottom edge  16  of the drum shell  12   2 . According to the second exemplary embodiment of an acoustic drum  10   2 , a ratio of the length D L2  to the length D U2  substantially equals to the “Golden Ratio”, i.e. 1.618033989. With the air vent in the upper “Golden Ratio” location (closer to the top head that is struck), more “attack”, the sound of the sticks striking the head, can be heard. This is advantageous for the player who wants a more “aggressive” and percussive sound. As previously noted, the location of the vent hole  22   1  may be located within a range of tolerance or deviation of about 10% from the exact location determined by the “Golden Ratio” without substantially deteriorating the sound quality of the drum. 
         [0027]    Further according to the second exemplary embodiment of the present invention, the acoustic drum  10   2  could be turned upside down to achieve more “deep”, melodious sound. 
         [0028]      FIG. 4  of the drawings illustrates a third exemplary embodiment of an acoustic drum  10   3  in accordance with the present invention. The acoustic drum  10   3  comprises a substantially cylindrical drum shell having two acoustic vent holes  22   1  and  22   2  formed in the drum shell. As illustrated in  FIG. 4 , the location of both the both acoustic vent holes  22   1  and  22   2  is determined by the “Golden Ratio”. Specifically, the location of the acoustic vent hole  22   1  is defined by the lower “Golden Ratio”, while the location of the acoustic vent hole  22   2  is defined by the upper “Golden Ratio”. According to the third exemplary embodiment, a plug can be provided to selectively plug the upper or lower acoustic vent holes  22   1  and  22   2  depending on the desired sound. Thus, one drum can have more “attack” by plugging the bottom air vent  22   1  or more “depth” (i.e., bottom) by plugging the upper air vent  22   2 . 
         [0029]    Therefore, in practical application of the present invention, it is possible to apply acoustic vent holes three ways: 
         [0030]    a) One air vent at the lower Golden Ratio location +/−a 10% deviation; 
         [0031]    b) One air vent at the upper Golden Ratio location +/−a 10% deviation; 
         [0032]    c) One air vent at the upper Golden Ratio location and another at the lower 
         [0000]    Golden Ratio location (with appropriate deviations), whereby the user selectively plug one air vent during use. 
         [0033]    Exemplary air vent positions (hole centers) from a lower bearing edge of an acoustic drum by using the Golden Ratio is shown in  FIG. 5 . 
         [0034]    On all drums it&#39;s possible to apply more than one air vent hole. As one would expect, more air vent holes increase the amount of air that can be purged. This is especially beneficial for larger drums, such as bass drums, that move a larger volume of air compared smaller drums. 
         [0035]    While the description thus far has focused on the specific and preferred embodiment where the Golden Ratio location exactly defines the location for the vent hole(s), it will be understood by those of skill in the art that the specific location may be varied from the exact location defined by the Golden Ratio without substantially detracting from the preferred performance defined by the Golden Ratio. Substantially the same performance may be obtained if the vent holes are located within about a 10% deviation from the exact location defined by the Golden Ratio. Therefore, the table shown in  FIG. 5  provides a series of examples for the exact location for the air vent with an acceptable margin or range of variation of about +/−10%. Based on tests conducted by the inventors, the calculation for the acceptable margin of variation uses a Golden Ratio range of 1.4562 to 1.7798. Thus, for the first example listed in  FIG. 5 , a product having a nominal shell depth of 76.2 mm would have an air vent located in a range of 27.4 mm to 31.0 mm from the lower bearing edge, and a product having a shell depth of 508 mm would have an air vent location of 182.7 mm to 206.8 mm from the lower bearing edge.  FIG. 5  shows these and other deviation ranges (“Air Vent Range of Deviation”) from the exact Golden Ratio location of the air vent for the shell sizes listed in  FIG. 5 . 
         [0036]    Other changes may be made to the foregoing invention without departing from the spirit and scope of the present invention as understood by those of skill in the art.