Abstract:
A drum pillow for use in a bass drum is disclosed herein. The drum pillow can be permanently or removably inserted into the interior of the bass drum shell. The preferred embodiment of the drum pillow is used to “deaden” or modify the sound, esp. overtones, of the bass drum during live performances, particularly when the drum is being struck by a typical foot-operated bass beater. An alternate embodiment is designed for use in studio recording sessions, where the situation calls for an even “deader” sound. Also disclosed herein is a method for using the drum pillow for the purposes described.

Description:
FIELD OF THE INVENTION 
     This invention relates generally to musical instrument accessories and more particularly to an insert for a bass drum that is used to “deaden” or modify the sound from the drum. 
     BACKGROUND OF THE FIELD 
     Many percussion instruments, particularly bass drums, have striking surfaces, i.e. drumheads, that vibrate to such an extent when struck that the sound produced thereby echoes and reverberates more than is desirable. Such overtones seriously reduce the quality of the sound from the drum. Consequently, in most situations, drummers would like to deaden, or dampen, the reverberation of the drumhead to produce a crisper, cleaner sound. 
     For years, drummers have been using various spontaneous methods to deaden the sound produced by the drums. One of these methods has been to toss loose rags or pillows inside the drum to absorb some of the sound overtones. Another method has been for the drummer to use his or her hand to directly dampen the vibrations of the drumhead. These methods have been used particularly with bass drums, which are large enough so that the inside of the drum can be easily accessed. 
     A bass drum is generally constructed of a cylindrical drum shell with two open ends, and at least one drumskin stretched across an open end forming a “drumhead.” The circular edge of the drumhead therefore coincides with the circular edge of the drum shell. The drum is usually positioned on the floor so that the drumhead is generally orthogonal to the floor. A foot-operated “bass beater” strikes the drumhead at a strike point somewhat higher than the exact geometric center of the drumhead. 
     There have been some patented devices directed toward such “sound-deadening” in bass drums. The Montano U.S. Pat. No. 5,233,898 discloses and claims a drum damper comprising cushioning means and fastening means similar to the present invention. However, Montano&#39;s fastening means is a very specific arrangement of two straps using anchors fixedly attached to the interior of the drum shell designed for holding the cushion in compression against both the drum shell and the drumhead. In contrast, the present invention does not use straps at all because the presence of any straps or other non-absorbing material over the drum pillow serves to detract from the acoustic functionality of the drum pillow. Furthermore, Montano&#39;s device has a contact surface that specifically covers 25% or less of the drumhead area generally below the strike point and including only a small part of the edge of the drumhead. Because the majority of the higher sound harmonics are generated at the edge of the drumhead, it would be desirable to have pillow contact, and therefore damping action, all along the edge of the drumhead. 
     Crago et al., in U.S. Pat. No. 5,088,376, discloses an hourglass-shaped drum pillow that is compressed between the two drumheads of a bass drum. The Crago device is specifically designed to be used only in a drum with two drumheads, and again, the pillow surface covers only a drumhead area generally below the strike point and including only a small part of the edge of the drumhead. 
     Arnold, Payson, and Beals et al., respectively in U.S. Pat. Nos. 6,043,420, 4,338,850, and 5,107,741, disclose quite complicated dampening devices that are hinged or otherwise swing so as to make and break contact with the drumhead and thereby selectively deaden the vibrations from the drumhead at various times during play (similar to use of the drummer&#39;s hand). These devices are difficult for the drummer to control, because they require so much attention and manipulation, and therefore are inconsistent, ineffective and less than optimal. 
     SUMMARY OF THE INVENTION 
     Because of the dual nature of the uses of bass drums, the present invention has been developed in two specific embodiments, one for live performances and one for studio recording sessions. The embodiment for live performances has been chosen as the preferred embodiment. It is believed that the qualities and characteristics of the invention will be best understood in the context of this preferred embodiment. 
     The preferred embodiment of the present invention comprises two identical foam pieces that have been acoustically shaped and designed to provide optimal sound quality when properly positioned within the drum shell of a bass drum so as to contact the entire circular edge of the drumhead. The four sides will be referred to as the contact surface (positioned against the drumhead), the outer surface (positioned against the drum shell), the inner surface (directed toward the interior of the drum), and the free surface (directed away from the drumhead). 
     Because most drummers prefer a dampened sound resulting from drumhead coverage (drum pillow contact) of approximately 25 percent of the total area, the preferred embodiment of the present invention covers approximately 25 percent of the entire drumhead area. However, because the majority of the higher sound harmonics are generated at the edge of the drumhead (where the drumhead vibrations encounter the drum shell and bounce back), the preferred embodiment of the present invention of the permanent drum pillow has been designed to provide pillow contact, and therefore damping action, all along the circular edge of the drumhead. (Previous drum pillow designs have covered only a small part of the drumhead edge.) Furthermore, the preferred embodiment is provided in two pieces, an upper portion and a lower portion, so that any particular drummer can remove the upper portion if he or she prefers a more “lively” sound from the drum. 
     The contact surface of each piece is generally planar and is intended to impinge against the inside of the drumhead so as to contact approximately 12 percent of the drumhead area. The outer curve of the contact surface simply follows the curve of the bass drum shell. The inner curve of the contact surface has been chosen so as to provide the requisite contact surface area. Experiments have shown that a bevel around the outer edge of the contact surface improves the fit of the drum pillow within the drum shell, particularly for drum shells with edge lips; however, it is important to keep the bevel relatively small so as not to interfere with the sound absorption characteristics of the drum pillow. 
     In the preferred embodiment, one or more Velcro™ strips hold the pieces of the drum pillow in place inside the drum shell. Obviously, different types of hook-and-loop fasteners or even different types of fasteners, such as snaps, could be used to secure the drum pillow in place. However, it has been found that the Velcro™ strips are effective while having the benefit of being easy to install while maintaining the structural and acoustic integrity of the drum shell, e.g., without drilling holes or making permanent indentations in the drum shell. In the preferred embodiment, one portion of the Velcro™ fastener is applied to the interior of the drum shell and one portion is applied to the drum pillow. The drum pillow can therefore be made a temporary or a permanent installation, according to the particular drummer and situation. 
     Each of the two pieces of the preferred embodiment of the drum pillow is made of a single piece of dense foam to absorb higher harmonics, and each is covered with a rayon (or preferably silk) slipcover to further clean up and sharpen the sound, as well as to improve and customize the drum pillow&#39;s appearance. Other devices, such as many of the patented devices above-mentioned, are constructed of two or more pieces, only one of which is sound-absorbing. However, it has been found that having the entire drum pillow made of dense foam shaped into the desired form, while being simple to manufacture and manipulate, provides optimal sound-absorption properties. 
     During sound recording sessions, in contrast to live performances, drummers and producers typically prefer a much “deader” sound from bass drums. Therefore, it is desirable that significantly more than 25 percent of the drumhead area be dampened. A first alternate embodiment of the present invention comprises a single, three-sided foam piece that has been acoustically shaped and designed to provide optimal sound quality for sound recording purposes. The geometric parameters of the sides have been carefully chosen after much acoustic experimentation focusing on sound quality and simplicity of design. The three sides will be referred to as the contact surface (positioned against the drumhead), the bottom surface (positioned against the drum shell), and the top surface. 
     The contact surface is generally planar and is intended to impinge against the inside of the drumhead so as to contact approximately 50% of the drumhead area. Instead of covering the drumhead edge, this first alternate embodiment covers an area of the drumhead generally below the strike point of the bass-beater. It has been shown that for optimal acoustics, the upper point of the contact surface of the drum pillow must impinge the drumhead at approximately the strike point of the bass beater. The lower curve of the contact surface simply follows the curve of the bass drum shell. Experiments have shown that a bevel around the lower edge of the contact surface improves the fit of the drum pillow; however, it is important to keep the bevel relatively small so as not to interfere with the sound absorption characteristics of the drum pillow. 
     The bottom surface of this first alternate embodiment of the present invention of the drum pillow is designed to mate with and fit into the curve of the drum shell. The top surface and the bottom surface are both designed to smoothly taper the drum pillow from the contact surface at the drumhead which is being stricken to the far point at the opposite drumhead or the open end of the drum shell (depending on whether there is a second drum head on the particular bass drum). 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a perspective view of the preferred embodiment of the drum pillow installed in a bass drum as it might be for live performance purposes; 
     FIG. 2 is a front view of the preferred embodiment of the permanent drum pillow installed in a bass drum as it might be for live performance purposes; 
     FIG. 3 is a sectional side view of the preferred embodiment of the permanent drum pillow; 
     FIG. 4 is a perspective view of the first alternate embodiment of the permanent drum pillow installed in a bass drum as it might be for studio recording purposes; 
     FIG. 5 is a front view of the first alternate embodiment of the permanent drum pillow; 
     FIG. 6 is a side view of the first alternate embodiment of the permanent drum pillow; and 
     FIG. 7 is a top view of the first alternate embodiment of the permanent drum pillow. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     FIG. 1 shows the preferred embodiment of the drum pillow  10  installed in a bass drum, the drum being in the usual position for live performances, i.e., generally orthogonal to the floor. The bass drum comprises a drumhead  12  stretched across one open end of a generally cylindrical drum shell  14 . The drum pillow  10  fits in the inside of the drum shell  14  such that the contact surface  16  impinges upon the drumhead  12 . It is seen that the drum pillow  10  when properly installed impinges the entire drum shell edge. 
     FIG. 2 shows the contact surface  16  in more detail. The upper portion  18  and the lower portion  20  together cover approximately 20% of the area of the drumhead  12 . (Alternatively, the drum pillow  10  could easily be provided as a single torus-shaped piece.) The mating surfaces  22  are typically located for convenience generally along the horizontal centerline of the drumhead  12  but could be located anywhere around the circumference, depending upon the installation of the drum pillow  10 . 
     The bevel  24  of the preferred embodiment of the drum pillow  10  extends all along the outer curve  26  of the contact surface  16  and aids in the fit of the drum pillow  10  within the drum shell  14 . Depending on the design of the particular bass drum and the desired acoustic characteristics of the drummer, there need not be a bevel at all. However, in the preferred embodiment, the bevel  24  measures approximately 0.75 inches along the contact surface  16  and approximately 1.50 inches along the outer surface  28  (best seen in FIG.  3 ), so that the overall slant of the bevel  24  is approximately 60 degrees from the contact surface  16 . It is found that if the bevel  24  is much larger, then the acoustic characteristics of the drum pillow  10  begin to degrade. 
     In the side view of FIG. 3, the reader can see the bevel  24  in profile. (Because the two portions  18  and  20  are identical, the two portions are mirror images of each other, and the opposite side of this view is also a mirror image of this view.) FIG. 3 also illustrates how the outer surface  28  extends generally orthogonally from the contact surface  16  approximately 4 inches. A greater length would result in a more dampened sound and a lesser length would result in a less dampened sound. However, the preferred length of 4 inches results in an acoustically optimal sound for live performances. In the preferred embodiment, the upper portion  18  and the lower portion  20  are attached to each other at the mating points  22  by Velcro™ fasteners. Any other appropriate fastener may be used. Velcro™ fasteners are also used in the preferred embodiment to removably attach the portions  18 ,  20  of the drum pillow  10  to the interior of the drum shell  14 . 
     FIG. 4 shows a first alternate embodiment of the drum pillow  40  installed in a bass drum, the drum being in the usual position for studio recording purposes, i.e., generally orthogonal to the floor. This perspective view shows how the drum pillow  40  fits in the inside of the drum shell  42  such that the contact surface  44  impinges upon the drumhead  46 . Again, Velcro™ fasteners are used between the drum pillow  40  and the drum shell  42  to hold the drum pillow  40  in position. 
     FIG. 5 shows the contact surface  44  in more detail. A crosshair representing the geometric center of a normal drumhead is shown for the convenience of the reader. In most bass drums, the radius of the drumhead is approximately 10.5 inches and the strike point of the bass beater is approximately 1 inch above the geometric center of the drumhead, or 11.5 inches from the lower edge of the drumhead. Therefore, in the first alternate embodiment of the drum pillow  40 , the apex  48  of the contact surface  44  is approximately 11.5 inches from the lower edge of the drumhead  46  and locates just above the center of the drumhead  46 . The generally planar area of the contact surface  44  approximates a semicircle such that the lower curve  50  generally follows the curve of the drum shell  42  and terminates in the two endpoints  52   a  and  52   b , typically located close to the horizontal diameter of the drumhead  46 . The upper curve  54  extends in both directions from the apex  48  and slopes gradually down to the endpoints  52   a,b . The endpoints  52   a,b  have been dropped down slightly below the horizontal so that the total area of the contact surface  44  will be approximately 50% of the area of the drumhead  46 . The definition of the curve  54 , and hence the locations of the endpoints  52   a,b , is not as important as the location of the apex  48  and the total drumhead coverage of the contact surface  44 . 
     As can be seen in FIG. 6, both the apex  48  and the far point  56  of the drum pillow  40  have been somewhat truncated, instead of forming sharp points. This truncation has been done for manufacturing purposes only because sharp edges in foam are difficult to shape and easily become deformed. It is not necessary for the performance of the drum pillow  40  that these two sharp points be truncated; and indeed too much of a truncation will adversely affect the acoustic characteristics of the drum pillow  40 . However, the truncation of the far point  56  may have another beneficial effect. If there is a second drumhead on the drum shell such that the far point  56  impinges upon this second drumhead, the second drumhead will be somewhat dampened as well. 
     In addition, FIG. 6 shows how the first alternate embodiment also includes a bevel  58 . (Because the drum pillow  40  is symmetrical, the opposite side is a mirror image of the side shown.) FIG. 6 also illustrates how the bottom surface  62  is bounded by the lower curve  50  of the contact surface  44  and the edge  64  between the bottom surface  62  and the top surface  60 . 
     FIGS. 6 and 7 considered together show how the top and bottom surfaces  60  and  62  taper from the contact surface  44  toward the far point  56 . The taper of the top surface is shaped not only to smoothly connect the contact surface to the bottom surface but also to accommodate a microphone within the drum shell. The rounded shape of the top surface provides better acoustics within the drum shell than a flat or angular surface would do. The overall length of the drum pillow  40  in the first alternate embodiment from the contact surface  44  to the far point  56  is approximately 14 inches, which is the usual length of a bass drum shell. The taper can be made more or less severe so that the overall length of the drum pillow will be more or less than 14 inches, according to the specific design and acoustic preferences of the drummer. Different tapering lengths will obviously give different acoustic properties; however, the current design of the first alternate embodiment was chosen to provide optimal acoustics for studio recording purposes.