Abstract:
A booth for confining and acoustically isolating musical drum instruments and musicians therefor has a rear wall, front wall assembly having a number of plastic windows interconnected in a polygonal path, and a ceiling member. The windows are supported by pedestal blocks and secured in place by vertically opposed troughs in the ceiling member and pedestal blocks.

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to the production of live music, and more particularly concerns apparatus for promoting compatible interaction between loud and soft instruments of a musical band. 
     2. Description of the Prior Art 
     In the playing of live music by a band of musicians on a stage in an auditorium or concert area, the nature of the acoustic interaction of the several involved musical instruments is of critical importance. The need for proper mixing of sounds is particularly desirable where the individual instruments involve electronic amplification. 
     In the case of drums, their best musical characteristics are usually produced at sound intensities considerably greater than the normal sound outputs of the other instruments. For this reason, the drum players and their instruments are sometimes enclosed in an isolating booth which adjusts the emergent sound to manageable stage levels while enabling electronic coupling to a sound-mixing system that outputs sound to the audience via loudspeakers. Because music bands usually have limited performances in a specific location, the drum isolating booth must be easily erected on site, then dismantled to an easily transportable compact state. 
     Earlier isolation booths have been of heavy, cumbersome construction, not easily assembled on stage and/or dismantled. Also, sound-absorbing efficiencies have been low because of design configurations and materials of construction. In particular, prior isolation booths have not addressed the fact that low frequency energy, typical of drum sounds, is very difficult to absorb, and such low frequencies tend to transfer throughout a room by coupling to the floor. 
     It is accordingly an object of the present invention to provide an acoustically isolating booth for drums and drum players. 
     It is a further object of this invention to provide a drum isolating booth of the foregoing objective which can be easily constructed and dismantled. 
     It is another object of the present invention to provide a drum isolating booth of the aforesaid nature which efficiently absorbs low frequency sounds typically produced by drums. 
     It is an additional object of the present invention to provide a kit of relatively compact size containing components for the easy construction of the aforesaid isolating booth. 
     These objects and other objects and advantages of the invention will be apparent from the following description. 
     SUMMARY OF THE INVENTION 
     The above and other beneficial objects and advantages are accomplished in accordance with the present invention by a booth adapted to be positioned upon a substantially flat floor surface and adapted to confine and acoustically isolate musical drum instruments and musicians therefor, said booth comprising a rear wall, front wall assembly comprised of a number of plastic windows releasibly interconnected in a polygonal path, and a roof member horizontally emplaced upon said rear wall and front wall assembly, said windows being supported by pedestal blocks, said rear wall, roof member, and pedestal blocks being fabricated of rigid sound-absorbing material. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWING 
       For a fuller understanding of the nature and objects of the invention, reference should be had to the following detailed description taken in connection with the accompanying drawing forming a part of this specification and in which similar numerals of reference indicate corresponding parts in all the figures of the drawing: 
         FIG. 1  is a perspective front view of a six-window embodiment of the acoustic isolating booth of the present invention. 
         FIG. 2  is a perspective rear view thereof. 
         FIG. 3  is a front view thereof. 
         FIG. 4  is a top view thereof with portions broken away. 
         FIG. 5  is an enlarged fragmentary horizontal sectional view taken in the direction of the arrows upon line  5 - 5  of  FIG. 3 . 
         FIG. 6  is an enlarged fragmentary sectional view taken in the direction of the arrows upon line  6 - 6  of  FIG. 4 . 
         FIG. 7  is an enlarged horizontal sectional view of the hinge component employed for joining the windows of the booth of  FIG. 1 . 
         FIG. 8  is an enlarged fragmentary sectional view taken in the direction of the arrows upon line  8 - 8  of  FIG. 5 . 
         FIG. 9  is a schematic top view of a first alternative embodiment having eight windows. 
         FIG. 10  is a schematic top view of a second alternative embodiment having twelve windows in a square array. 
         FIG. 11  is a schematic top view of a third alternative embodiment having eight windows in a trapezoidal array. 
     
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT 
     Referring now to  FIGS. 1-4 , an embodiment of the acoustic isolating booth  10  of this invention is shown comprised of vertically oriented rear wall  11  of substantially flat construction, front wall assembly  12  projecting convexly from rear wall  11 , and ceiling member  13  of flat construction overlying said rear wall and front wall assembly to form therewith an enclosed booth space  14 . 
     Rear wall  11  is comprised of opposed outer panels  15  of vertically elongated, substantially rectangular configuration, and paired center sliding door panels  16  interactive with outer panels  15 . Panels  15  and  16 , and other panel components subsequently described herein, are constructed of fabric-covered bonded rockwool having the characteristics defined in U.S. Pat. Nos. 5,644,872 and 7,178,630, incorporated herein by reference. In particular, said panels are produced by the spinning of molten mineral magma to form fibers of indeterminate length in layers which constitute a loose batting. Bonding agents such as phenolic resins are applied to the batting along with compactive force to produce interadherance of the fibers and a resultant self-supporting panel of controllable density. Preferred densities for the purposes of the present invention are in the range of 5 to 9 pounds/cu.ft. It has been found that, at densities below 5 lbs/cu.ft., the panels have inadequate rigidity for use in the booth structure of this invention, and at densities greater than 9 lbs/cu.ft., the panels provide inadequate absorption of sound. Within said preferred density range, said panels have a compressive modulus of 200 to 400 lbs/sq.ft. at 10% compression, and have a noise reduction coefficient (NRC) rating above, namely better than 1.20 at typical drum-produced frequencies below 125 Hz. 
     Panels  15  and  16  are each bounded by flat interior and exterior faces  18  and  19 , respectively, and four straight flat perimeter edge surfaces  21  disposed in a rectangular configuration. Said panels are covered with a tautly drawn heavy duty fabric layer  22  similar to that shown in  FIG. 8  which is bonded to the underlying rockwool  44  and folded over each edge and bonded to itself upon each edge surface. The panels have a uniform thickness in the range of 1.5 to 3.0 inches, a height of about six to seven feet, and a width, measured between vertical edge surfaces  21 , of between 1.5 and 3.0 feet. 
     Front wall assembly  12  is comprised of upper portion  24  having a series of plastic windows  25 , and a footing portion  26  which supports said windows. Said windows are preferably fabricated of polycarbonate or polyacrylic sheeting of ⅛″ to ¼″ thickness, and have a vertically elongated rectangular configuration with a height of 4 to 5 feet and width of about 2 feet. The vertical edges  27  of contiguous windows are interconnected by connector strips  28  which frictionally grip the windows. Preferred connector strips are fabricated of a clear resilient plastic such as plasticized polyvinyl chloride (PVC) or silicone. As best shown in  FIG. 7 , the connector strip is preferably an extruded shape having opposed pairs of gripping arms  29  separated by a compliant intervening strip  30  which functions as a “living” hinge. Protuberances  31  integral with the facing surfaces of arms  29  enhance the frictional holding power of said arms. The embodiment exemplified in  FIGS. 1-4  has six windows interconnected upon a semi-circular path to form upper portion  24  having opposed terminal edges  32  that interact with rear wall  11 . 
     Footing portion  26  is comprised of a series of pedestal blocks  33 , the number of which corresponds to the number of windows. The blocks are of substantially the same construction as the aforementioned rear wall panels  15  and  16 , but have a somewhat greater thickness of about 4½″. Also, the opposed vertical edge surfaces  34  of the blocks are convergently angled toward the interior face  35  of the block, producing a trapezoidal top profile. Hook and loop fiber fastening strips such as VELCRO  45  are attached to edge surfaces  34 , thereby permitting sequential interengagement of the blocks upon a flat floor surface. A centered trough  36  of about ¼″ depth is centered in the upper edge surface  37  of each block for the purpose of seating the lowermost edge of an associated window. The blocks  33  further serve to absorb reverberation sound within the booth, and minimize sound transmission through the floor, which is an otherwise significant problem with the low frequency sounds produced by drums. Another advantage of the specialized characteristics and placement of the blocks is that they permit passage of speaker cables on the floor beneath the blocks without impairing the sound-absorbing efficiency of the booth. 
     Ceiling member  13  is comprised of two or more large panels  38  horizontally placed to seat upon the upper edges of the windows and rear wall  11 . VELCRO material may be used to secure rear panel  38  to the upper edges of panels  15 . Panels  38  are otherwise of essentially the same construction as panels  15  and  16 . Troughs  40  of about ¼″ depth are recessed into the lower surfaces of panels  38  at peripheral locations to receive and secure the upper edges of the windows. Except for the staggered positioning of door panels  16 , the assembled booth has a plane of symmetry  42  vertically centered between terminal edges  32  of said window assembly. 
     The first, second and third alternative embodiments of the acoustic isolation booth of the present invention, shown in  FIGS. 9 ,  10  and  11 , respectively, differ from the primary embodiment of  FIGS. 1-4  substantially only in the manner of securement of the lower extremities of the windows by the pedestal blocks, and the geometrical floor plan of the wall assembly. In particular, the securing troughs  36 , instead of being centered within upper edge surface  37  of each pedestal block, is angularly positioned, and at least two separate troughs meet at an apex  47  within edge surface  37 . Such modifications have been found to impart increased structural integrity to the wall assembly, and increased attenuation of sound within the booth. 
     The aforesaid components of the booth are employed as a kit of relatively compact size which facilitates transportation and storage, and enables the booth to be easily installed upon a flat surface, and easily dismantled. For compactness, the windows, preferably of identical size for a particular booth, may be stacked, then interconnected at the site of construction. The fact that the kit includes multiple identical components such as the windows and footing panels, facilitates rapid assembly. No tools are necessary because of the self-integrating features of the several components. 
     While particular examples of the present invention have been shown and described, it is apparent that changes and modifications may be made therein without departing from the invention in its broadest aspects. The aim of the appended claims, therefore, is to cover all such changes and modifications as fall within the true spirit and scope of the invention.