Abstract:
In accordance with at least one embodiment: a muffler with a case (comprised of at least one inlet, at least one outlet, and a body), and elongated members comprised of material capable of a predetermined resonance. The elongated members have sufficient length after their final point of attachment to vibrate when exposed to flowing exhaust gasses. This vibration results in resonance that is noise canceling and/or sound enhancing. The muffler may also contain any combination of sound baffles, sound absorbent material, and other sound altering devices.

Description:
BACKGROUND 
     Prior Art 
     The following is a tabulation of various prior art that appears presently relevant: 
     
       
         
               
             
               
               
               
               
             
               
               
               
               
             
           
               
                   
               
               
                 U.S. Patents 
               
             
          
           
               
                 Pat. No. 
                 Kind Code 
                 Issue Date 
                 Patentee 
               
               
                   
               
             
          
           
               
                 582,485 
                 (N/A) 
                 May 5, 1897 
                 Reeves, Reeves 
               
               
                 4,574,914 
                 A 
                 Mar. 3, 1986 
                 Flugger 
               
               
                 7,219,764 
                 B1 
                 May 22, 2007 
                 Forbes 
               
               
                 1,029,162 
                 B1 
                 Mar. 23, 2005 
                 Flugger 
               
               
                 5,434,374 
                 A 
                 Jul. 18, 1995 
                 Tien-Chu Hsueh 
               
               
                 20040108162 
                 A1 
                 Jun. 10, 2004 
                 Gilles Couvrette 
               
               
                   
               
             
          
         
       
     
     Nonpatent Literature Documents 
     
         
         Wilder, Jim,  Undercar Digest , “A Different Muffler, Going to Market Differently” (April 2009) 
       
    
     Since the advent of the internal combustion engine, people have sought to control its sound. Milton and Marshall Reeves were presumably the first to address this dilemma; their patent for “Exhaust-Muffler For Engines” was issued in 1897. Their muffler, along with other mufflers of the time (and today), was intended only to attenuate sound. Over time, a significant demand grew for mufflers with pleasing sound and greater exhaust gas flow. Greater flow results in better engine performance and increased fuel economy, but is difficult to achieve in mufflers due to the back-pressure created by manipulating exhaust. Muffler manufactures responded to the demand for greater flow with a limited degree of success. 
     Several designs (such as Flugger&#39;s) have sought to achieve low back-pressure, and (perhaps to a lesser extent) pleasing sound. Low back pressure (greater flow) results in better engine performance and increased fuel economy, but there is a limit on how much flow can be achieved. Virtually all mufflers rely on either physically altering the path of exhaust gasses (passive-reactive type), using sound absorbent material (absorptive type), or both. Due to this, undesirable back pressure is invariably created, and is particularly extreme on mufflers designed to fully silence. 
     Several ideas have been proposed to deal with the problem of back pressure, but virtually all fail to some degree. A particularly interesting proposition is the active-reactive muffler. In essence, active-reactive mufflers function by electronically monitoring the sound produced by exhaust, then sending noise canceling sound waves back into the exhaust system via a speaker. Although this seems promising at face value, it results in many new problems and limitations. Active-reactive mufflers have existed for decades, but have seen comparatively little commercial success. Reasons for this include: 
     (a) The sheer sophistication of the system results in the risk of component failure; the computer could malfunction, the sensors could degrade in the presence of exhaust gasses and heat, the speaker could rupture, the cables could corrode, etc. 
     (b) The expense of implementing such a system is typically much greater than a traditional muffler. 
     (c) It is likely unfeasible or perhaps impossible to selectively control sound cancellation well enough to compete in the performance exhaust market. 
     (d) It is difficult to account for different types of engines, and therefore difficult or impossible to fully incorporate into the aftermarket. 
     Amongst engine and automobile enthusiasts, we have found that pleasing sound is at least as important as exhaust flow. Although modern performance mufflers offer more sound than mufflers intended for silencing, there are still many problems that plague the industry. Attempts at correcting these problems have been mediocre at best. 
     A particularly notorious problem among exhaust (especially performance exhaust) is what is popularly known as “drone”. Especially prominent among “welded-type” mufflers (such as Flugger&#39;s), drone refers to a sustained low frequency tone that can be heard at certain RPMs. This noise is usually perceived as irritating and undesirable. Some mufflers are less prone to this problem, but have other problems in its place. Forbes has recently found a possible, partial solution to drone, but offers no indication that any other issues are addressed. 
     Another common problem we have found among performance mufflers is a popping sound, which usually occurs during rapid drops in RPM (such as releasing the accelerator pedal). This phenomenon is created by pockets of exhaust gasses building and releasing. This can be caused by engine issues, back-pressure, low pressure zones in mufflers, and a plethora of other variables. This problem is often exacerbated by tail pipes. Popping exhaust is a fairly common problem, but extremely difficult to circumvent with mufflers designed for medium to loud volume. 
     We have found that a lack of refined sound (a “muddy” tone) is extremely common across the entire performance muffler spectrum, and is often perceived among consumers as “unnatural”, “undesirable”, or just plain “ugly”. This is because it is difficult to improve the underwhelming sounds of a damaged or non-performance engine via exhaust. Although some attempts have been made to offer performance sound to stock and/or aging engines, we have found the results to be lackluster at best. While it is true that some muffler designs may make engine problems less audible, we have found that the sound is not at all comparable to a true performance engine. 
     Advantages 
     Accordingly, several advantages for one or more aspects are as follows: a muffler that has extremely low back-pressure, is highly reliable, is suitable for a wide variety of markets, that addresses problems such as “drone” and “popping”, that provides a crisp and natural sound, and that potentially corrects undesirable sounds produced by an engine. Other advantages of one or more aspects will become apparent after consideration of the drawings and ensuing description. 
     SUMMARY 
     In accordance with at least one embodiment: a muffler with a case comprising a body, at least one inlet, and at least one outlet. A plurality of elongated members produce resonance when subjected to flowing exhaust gasses, which results in noise canceling and/or sound enhancing tones. Sound altering devices, such as sound baffles, sound absorbent material, and/or electronic noise canceling may be used in addition to the elongated members. 
     GLOSSARY OF TECHNICAL TERMS 
     
         
         
           
             Absorptive Muffler: A muffler that utilizes sound absorption. 
             Active-Reactive Muffler: A muffler that utilizes electronic sound cancellation. 
             Aftermarket: The market in which third-party parts companies compete. 
             Attenuation: To reduce sound levels. 
             Back Pressure: Restriction in the exhaust of an engine. 
             Body: In this specification, the body is the main section of a muffler. It typically (but not always) houses most or all of the internal components. A body is part of a case. 
             Branches: In this specification, “branches” refers to elongated members that stem from other elongated members. 
             Case: In this specification, the case is the body, inlet, and outlet of a muffler. 
             Cylinder: A three dimensional shape with straight parallel sides and a circular or oval section. 
             Drone: A sustained, usually low frequency tone that is typically considered undesirable. 
             Elongated Members: In this specification, “elongated members” refers to elongated members possessing resonating properties (refer to detailed description and operation for  FIG. 1 , and claims for a specificities). 
             Holding Ring: A device that allows components to attach to the case. 
             Inlet: The entrance of a muffler. Part of the case. 
             Muffler: A device that alters the sound of exhaust produced by an internal combustion engine. 
             Outlet: The exit of a muffler. Part of the case. 
             Passive-Reactive Muffler: A muffler that utilizes sound deflection. 
             Perforation: Holes in an object. 
             Polyhedron: A three dimensional shape with multiple sides. 
             Popping: An undesirable sound that can occur in exhaust systems, particularly during rapid drops in RPM. 
             Resonance: Sound created as a reaction from a stimulus. 
             (Sound) Absorption: To absorb sound (through materials such as fiberglass, steel wool, etc.) for the purpose of noise canceling and/or altering tone. 
             (Sound [or Deflection]) Baffle: A device used to create sound deflection. 
             (Sound) Deflection: Manipulating the path of sound waves to create sound canceling effects. 
             Suspend: To hang. 
             Tail Pipe: Exhaust pipe after a muffler. 
           
         
       
    
    
    
     
       DRAWINGS 
       Figures 
         FIG. 1  shows a perspective view of the first embodiment, with two elongated members, and a small cylindrical-bodied case. 
         FIG. 2  shows an embodiment with a deflection baffle. 
         FIG. 3  shows an embodiment with a third elongated member. 
         FIG. 4  shows an embodiment with an oval deflection baffle, stemming from an outlet. 
         FIG. 5  shows an embodiment with a “v”-shaped deflection baffle, stemming from the outlet. 
         FIG. 6  shows an embodiment with multiple sets of elongated members. 
         FIG. 7  shows an embodiment with cylindrical elongated members. 
         FIG. 8  shows an embodiment with a set of perforated cylindrical elongated members, and a set of non-cylindrical elongated members. 
         FIG. 9  shows an embodiment with perforated cylindrical elongated members. 
         FIG. 10  shows an embodiment with elongated members attached inside a muffler body (in this case, using a holding ring). 
         FIG. 11  shows an embodiment with multiple sets of elongated members attached to the body (in this case, using a holding ring). 
         FIG. 12  shows an embodiment with a set of elongated members attached to an inlet, and a set of elongated members attached to the body (in this case, using a holding ring). 
         FIG. 13  is a plan view of an embodiment with flat (technically polyhedral) elongated members. 
         FIG. 14  shows an embodiment with a “v”-shaped deflection baffle (attached to the body). 
         FIG. 15  shows an embodiment with sound absorbent material. 
         FIG. 16  shows an embodiment with three elongated members. 
         FIG. 17  shows an embodiment with multiple, branching elongated members. 
         FIG. 18  shows an embodiment with a large cylindrical-bodied case. 
         FIG. 19  shows an embodiment with a large cylindrical-bodied and a deflection baffle. 
         FIG. 20  shows an embodiment with a large cylindrical-bodied case and elongated members attached to the body (in this case with a holding ring). 
         FIG. 21  shows an embodiment with a large cylindrical-bodied case and multiple sets of elongated members. 
         FIG. 22  shows a perspective view of an embodiment with a full baffling system. 
         FIG. 23  shows a plan view of the embodiment in  FIG. 22 . 
         FIG. 24  shows an embodiment with a polyhedron case. 
         FIG. 25  shows an embodiment with curved elongated members 
     
    
    
     DRAWINGS 
     Reference Numerals 
     
         
         
           
               50 A: small cylindrical-bodied case 
               50 B: large cylindrical-bodied case 
               50 C: polyhedral-bodied case 
               10 : small cylindrical body 
               10 B: large cylindrical body 
               10 C: polyhedral body 
               12 : inlet 
               14 : outlet 
               16 A- 16 MM: elongated member 
               18 A- 18 M: elongated member assembly 
               20 : deflection baffle 
               24 : oval deflection baffle 
               26 : suspended “v”-shaped deflection baffle 
               28 A- 28 D: holding ring 
               30 : body-mounted “v”-shaped deflection baffle 
               32 : sound absorbent material 
               34 : baffle assembly 
               36 : baffle assembly front cradle 
               38 : baffle assembly holding ring 
               40 : perforated baffle 1 
               42 : perforated baffle 2 
               44 : perforated baffle 3 
           
         
       
    
     DETAILED DESCRIPTION 
     FIG.  1 —First Embodiment 
     One embodiment of the muffler is illustrated as a perspective view in  FIG. 1 . The figure shows a small cylindrical-bodied case  50 A, comprised of a small cylindrical body  10 , an inlet  12 , and an outlet  14 . An elongated member assembly  18 A, comprised of two elongated members  16 A and  16 B, is attached inside the inlet  12 . The elongated members  16 A and  16 B are made of steel in this embodiment, but can be made of any material capable of sufficient resonance. The elongated members in this embodiment are partial cylinders. 
     OPERATION 
     FIG.  1 —First Embodiment 
     When the inlet  12  is attached to the exhaust system of an engine (not shown), exhaust gasses are allowed to pass through the small cylindrical-bodied case  50 A. As the gasses (and their sound waves) pass by elongated member assembly  18 A, elongated members  16 A and  16 B respond by vibrating. This is possible because the members are made of a resonant material (in this embodiment, steel), and because they extend sufficiently past their final attaching point (in this embodiment, the inlet  12 ). As a result of the vibrations, resonant tones are generated. These resonant tones can be noise canceling, sound enhancing, or both. Because the members are directly excited by the exhaust gasses, the tones generated are directly correlated to the natural sound of the exhaust. The members are capable of producing sound waves opposite of some or all of those produced by an engine. This phenomenon results in the sound waves collapsing, creating noise cancellation. It is also possible for the members to generate additive tones when vibrating, which results in a more pleasing sound. Because there is very little to physically get in the way of exhaust gasses, back-pressure is extremely low. As of this time, we have found that 2 half-pipe-shaped steel members about 20 centimeters long works well across a wide variety of applications for a combination of noise canceling and pleasing sound. However, the device is not limited to these specifications in any way. Different materials, lengths, shapes, different numbers of members, etc. can be used. 
     DETAILED DESCRIPTION 
     FIG.  2 —Second Embodiment 
       FIG. 2  shows the same elements as  FIG. 1 , with the addition of a deflection baffle  20 . 
     OPERATION 
     FIG.  2 —Second Embodiment 
     After passing by elongated member assembly  18 A (the effect described in the operation of  FIG. 1 ), some of the exhaust gasses flow directly out of the case  50 A, while some are forced to the sides of deflection baffle  20 , where they deflect between the baffle and the small cylindrical body  10 . This results in further noise cancellation. The gasses eventually flow out of the case  50 A via the outlet  14 . 
     DETAILED DESCRIPTION 
     FIG.  3 —Third Embodiment 
       FIG. 3  shows the same elements as  FIG. 1 , with elongated member assembly  18 AA in place of elongated member assembly  18 A. Elongated members  16 Z,  16 A, and  16 B make up elongated member assembly  18 AA. 
     OPERATION 
     FIG.  3 —Third Embodiment 
     As described in the operation of  FIG. 1 , elongated members  16 A and  16 B create resonance as exhaust gasses flow by them. The addition of elongated member  16 Z changes the nature of the resonance. As well, the “v”-shaped tip of elongated member  16 Z slows down the exhaust gasses, allowing them to be further altered. 
     DETAILED DESCRIPTION 
     FIG.  4 —Fourth Embodiment 
       FIG. 4  shows the same elements as  FIG. 1 , with the addition of an oval deflection baffle  24  which is attached to the outlet  14  and protrudes into the small cylindrical body  10 . 
     OPERATION 
     FIG.  4 —Fourth Embodiment 
     After passing by elongated member assembly  18 A, the flow of the exhaust gasses is interrupted by oval deflection baffle  24 . Exhaust gasses are forced to go around the baffle, which slows down the flow, as well as creates noise canceling deflection between the baffle and the small cylindrical body  10 . 
     DETAILED DESCRIPTION 
     FIG.  5 —Fifth Embodiment 
       FIG. 5  shows the same elements as  FIG. 1 , with the addition of a suspended “v”-shaped deflection baffle  26  which is attached to the outlet  14  and protrudes into the small cylindrical body  10 . 
     OPERATION 
     FIG.  5 —Fifth Embodiment 
       FIG. 5  operates the same as  FIG. 4 , with suspended “v”-shaped deflection baffle  26  in place of the oval deflection baffle  24 . This results in different sound characteristics than other embodiments. 
     DETAILED DESCRIPTION 
     FIG.  6 —Sixth Embodiment 
       FIG. 6  shows the same elements as  FIG. 1 , with an elongated member assembly  18 B (comprised of two elongated members  16 E and  16 F) in place of elongated member assembly  18 A. In addition, another elongated member assembly  18 C, comprised of elongated members  16 C and  16 D, is attached to the outlet  14 . 
     OPERATION 
     FIG.  6 —Sixth Embodiment 
     After passing by elongated member assembly  18 B (functionally virtually the same as elongated member assembly  18 A), the exhaust gasses are further altered by elongated member assembly  18 C. Elongated member assembly  18 C operates the same as elongated member assembly  18 A, but is attached to the outlet  14 , allowing the exhaust gasses to be further altered before exiting. 
     DETAILED DESCRIPTION 
     FIG.  7 —Seventh Embodiment 
       FIG. 7  shows the same elements as  FIG. 1 , with an elongated member assembly  18 D, comprised of two elongated members  16 G and  16 H, in place of elongated member assembly  18 A. Elongated members  16 G and  16 H are both cylindrical in shape, open on both ends, and attached to the inlet  12 . 
     OPERATION 
     FIG.  7 —Seventh Embodiment 
       FIG. 7  operates the same as  FIG. 1 , but elongated members  16 G and  16 H are cylindrical, which allows exhaust gasses to flow through the members as well as by them. This results in different sound characteristics than those produced by other embodiments. 
     DETAILED DESCRIPTION 
     FIG.  8 —EIGHT EMBODIMENT 
       FIG. 8  shows small cylindrical-bodied case  50 A, and an elongated member assembly  18 E, comprised of two elongated members  16   i  and  16 J, attached to the inlet  12 . The elongated members  16   i  and  16 J are both cylindrical in shape, open on both ends, and perforated. Another elongated member assembly  18 C is attached to the outlet  14 , and is comprised of elongated members  16 C and  16 D. 
     OPERATION 
     FIG.  8 —Eighth Embodiment 
       FIG. 8  operates the same as  FIG. 6 , but with an elongated member assembly  18 E replacing  FIG. 6 &#39;s elongated member assembly,  18 B. Perforation allows exhaust gasses to flow in and out of the cylindrical members. This results in different sound characteristics than those produced by other embodiments. 
     DETAILED DESCRIPTION 
     FIG.  9 —Ninth Embodiment 
       FIG. 9  shows the small cylindrical-bodied case  50 A, and elongated member assembly  18 E, comprised of elongated members  16   i  and  16 J, attached to the inlet  12 . The elongated members  16   i  and  16 J are both cylindrical in shape, open on both ends, and perforated. 
     OPERATION 
     FIG.  9 —Ninth Embodiment 
       FIG. 9  operates the same as  FIG. 7 , but with elongated members  16   i  and  16 J, which are both perforated and cylindrical. This allows exhaust gasses to flow in and out of the members, resulting in different sound characteristics than those produced by other embodiments. 
     DETAILED DESCRIPTION 
     FIG.  10 —Tenth Embodiment 
       FIG. 10  shows the small cylindrical-bodied case  50 A, and an elongated member assembly  18 F, comprised of two elongated members  16 K and  16 L, attached to a holding ring  28 A, which is in turn attached to the small cylindrical body  10 . 
     OPERATION 
     FIG.  10 —Tenth Embodiment 
       FIG. 10  operates the same as  FIG. 1 , but instead of elongated members  16 A and  16 B, this embodiment uses elongated members  16 K and  16 L, attached to the holding ring  28 A, which in turn is attached to the small cylindrical body  10 . This results in different sound characteristics than those produced by other embodiments. 
     DETAILED DESCRIPTION 
     FIG.  11 —Eleventh Embodiment 
       FIG. 11  shows the same elements as  FIG. 10 , with the addition of another elongated member assembly  18 J, comprised of two elongated members  16 W and  16 X, and a holding ring  28 B. 
     OPERATION 
     FIG.  11 —Eleventh Embodiment 
       FIG. 11  operates the same as  FIG. 10 , but with a second elongated member assembly  18 J. This allows the exhaust gasses to be further manipulated, resulting in different sound characteristics than those produced by other embodiments. 
     DETAILED DESCRIPTION 
     FIG.  12 —Twelfth Embodiment 
       FIG. 12  shows the same elements as  FIG. 1 , with the addition of another elongated member assembly  18 J, comprised of elongated members  16 W and  16 X, and the holding ring  28 B. 
     OPERATION 
     FIG.  12 —Twelfth Embodiment 
       FIG. 12  operates the same as  FIG. 11 , but with one of the elongated member assemblies  18 A attached to the inlet  12 . This results in different sound characteristics than those produced by other embodiments. 
     DETAILED DESCRIPTION 
     FIG.  13 —Thirteenth Embodiment 
       FIG. 13  shows a plan view of an embodiment comprising of small cylindrical-bodied case  50 A, and an elongated member assembly  18 G, comprised of two elongated members  16 M and  16 N, attached inside the inlet  12 . Elongated members  16 M and  16 N are flat (technically polyhedral, as all physical objects have depth). 
     OPERATION 
     FIG.  13 —Thirteenth Embodiment 
       FIG. 13  operates the same as  FIG. 1 , but with elongated member assembly  18 G in place of  18 A. This results in different sound characteristics than those produced by other embodiments. 
     DETAILED DESCRIPTION 
     FIG.  14 —Fourteenth Embodiment 
       FIG. 14  shows the same elements of  FIG. 13 , with the addition of a body-mounted “v”-shaped deflection baffle  30 . 
     OPERATION 
     FIG.  14 —Fourteenth Embodiment 
       FIG. 14  operates the same as  FIG. 13 , with the addition of body-mounted “v”-shaped deflection baffle  30 . Exhaust gasses are forced to go around the baffle, which slows down the flow, as well as creates noise canceling deflection between baffle  30  and the small cylindrical body  10 . 
     DETAILED DESCRIPTION 
     FIG.  15 —Fifteenth Embodiment 
       FIG. 15  shows the same elements as  FIG. 13 , with the addition of sound absorbent material  32  (examples of sound absorbent materials include (but is not limited to) fiberglass packing and steel wool). 
     OPERATION 
     FIG.  15 —Fifteenth Embodiment 
       FIG. 15  operates the same as  FIG. 13 , with the addition of sound absorbent material  32 . Some of the exhaust gasses are caught by the sound absorbent material  32 , which results in lower volume and altered tone quality. 
     DETAILED DESCRIPTION 
     FIG.  16 —Sixteenth Embodiment 
       FIG. 16  shows the same elements as  FIG. 13 , with the addition of a third elongated member  16   o , which along with elongated members  16 M and  16 N, make up the elongated member assembly  18 H. 
     OPERATION 
     FIG.  16 —Sixteenth Embodiment 
       FIG. 16  operates the same as  FIG. 13 , with the addition of a third elongated member  16   o . This results in different resonant frequencies than those produced by the embodiment illustrated in  FIG. 13 . 
     DETAILED DESCRIPTION 
     FIG.  17 —Seventeenth Embodiment 
       FIG. 17  shows a plan view of an embodiment comprising of small cylindrical-bodied case  50 A, and the elongated members assembly  18   i  (which is comprised of elongated members  16 P,  16 Q,  16 V,  16 R,  16 S,  16 T, and  16 U). Elongated members  16 R,  16 S,  16 T, and  16 U are referred to as “branches” because they stem from elongated members  16 P,  16 Q, and  16 V, respectively. Elongated member assembly  18   i  is attached to the inlet  12 . 
     OPERATION 
     FIG.  17 —Seventeenth Embodiment 
       FIG. 17  operates the same as  FIG. 1 , with elongated member assembly  18   i  in the place of elongated member assembly  18 A. Elongated members  16 P,  16 Q,  16 R,  16 S,  16 T, and  16 U all interact with each other as exhaust gasses flow past them, resulting in a complex array of resonant frequencies. 
     DETAILED DESCRIPTION 
     FIG.  18 —Eighteenth Embodiment 
       FIG. 18  shows a large cylindrical-bodied case  50 B, comprised of a large cylindrical body  10 B, inlet  12 , and outlet  14 . An elongated member assembly  18 K, comprised of elongated members  16 Y and  16 AA, is attached inside the inlet  12 . 
     OPERATION 
     FIG.  18 —Eighteenth Embodiment 
       FIG. 18  operates the same as  FIG. 1 , with elongated member assembly  18 K in the place of elongated member assembly  18 A, the large cylindrical-bodied case  50 B in the place of the small cylindrical-bodied case  50 A, and the large cylindrical body  10 B in the place of the small cylindrical body  10 A. The large case results in different sound characteristics than those produced by other embodiments. 
     DETAILED DESCRIPTION 
     FIG.  19 —Nineteenth Embodiment 
       FIG. 19  shows the same elements as  FIG. 18 , with the addition of deflection baffle  20 . 
     OPERATION 
     FIG.  19 —Nineteenth Embodiment 
       FIG. 19  operates the same as  FIG. 18 , with the addition of deflection baffle  20 . After passing the elongated member assembly  18 K, some of the exhaust gasses flow directly out, while some are forced to the sides of the deflection baffle  20 , where they deflect between the baffle  20  and large cylindrical body  10 B. This results in further noise cancellation. The gasses eventually flow out of the case  50 A via the outlet  14 . 
     DETAILED DESCRIPTION 
     FIG.  20 —Twentieth Embodiment 
       FIG. 20  shows the large cylindrical-bodied case  50 B, an elongated member assembly  18 L (comprised of elongated members  16 BB and  16 CC), and holding ring  28 C (which is attached to the large cylindrical body  10 B). 
     OPERATION 
     FIG.  20 —Twentieth Embodiment 
       FIG. 20  operates the same as  FIG. 18 , but instead of elongated members  16 Y and  16 AA, this embodiment uses elongated members  16 BB and  16 CC, attached to the holding ring  28 C, which in turn is attached to the large cylindrical body  10 B. This results in different sound characteristics than those produced by other embodiments. 
     DETAILED DESCRIPTION 
     FIG.  21 —Twenty First Embodiment 
       FIG. 21  shows the large cylindrical-bodied case  50 B, an elongated member assembly  18 M (comprised of elongated members  16 DD,  16 EE,  16 FF,  16 GG,  16 HH,  16   ii , and holding ring  28 D). The elongated member assembly  18 M is attached to the body  10 B. 
     OPERATION 
     FIG.  21 —Twenty First Embodiment 
     After entering the large cylindrical body  10 B via the inlet  12 , the exhaust gasses flow into one of the three holes in holding ring  28 D. Inside each hole is a set of elongated members. As the exhaust gasses pass through the elongated members, they vibrate amongst each other, creating complex resonant frequencies. The exhaust gasses then exit through outlet  14 . 
     DETAILED DESCRIPTION 
     FIG.  22  AND FIG.  23 —Twenty Second Embodiment 
       FIG. 22  and  FIG. 23  show the large cylindrical-bodied case  50 B, an elongated member assembly  18 N (comprised of elongated members  16 JJ and  16 KK and attached to the inlet  12 ). In addition,  FIGS. 22 and 23  show a baffle assembly  34 , comprised of a baffle assembly front cradle  36 , baffle assembly holding ring  38 , perforated baffle 1  40 , perforated baffle 2  42 , and perforated baffle 3  44 . 
     OPERATION 
     FIG.  22  AND FIG.  23 —Twenty Second Embodiment 
     After passing by the elongated member assembly  18 N, the exhaust gasses flow into either perforated baffle 2  42  or perforated baffle 3  44 . From there the exhaust gas either flows out of the perforations, or travels to the end of their respective baffles before hitting the large cylindrical body  10 B, then turning around and flowing into perforated baffle 1  40  (this is possible because the baffle assembly holding ring  38  is open in its center). The exhaust gasses then exit through outlet  14 . 
     DETAILED DESCRIPTION 
     FIG.  24 —Twenty Third Embodiment 
       FIG. 24  shows a polyhedral-bodied case  50 C, comprised of a polyhedral body  10 C, inlet  12 , and outlet  14 . An elongated member assembly  18 K, comprised of elongated members  16 Y and  16 AA, is attached inside the inlet  12 . 
     OPERATION 
     FIG.  24 —Twenty Third Embodiment 
       FIG. 24  operates the same as  FIG. 18 , with polyhedral-bodied case  50 C in place of the large cylindrical-bodied case  50 B. 
     DETAILED DESCRIPTION 
     FIG.  25 —Twenty Fourth Embodiment 
       FIG. 25  shows the same elements as  FIG. 18 , with elongated member assembly  18 M in place of elongated member assembly  18 K. Elongated member assembly  18 M is comprised of elongated members  16 LL and  16 MM, which are both curved. 
     OPERATION 
     FIG.  25 —Twenty Fourth Embodiment 
       FIG. 25  operates the same as  FIG. 18 , with elongated member assembly  18 M in place of elongated member assembly  18 K. Because the members comprising elongated member assembly  18 K are curved, different sounds are created in comparison to other embodiments. 
     CONCLUSIONS, RAMIFICATIONS, AND SCOPE 
     Accordingly, the reader will see that resonance generating mufflers of the various embodiments are capable of generating tones that are noise canceling and/or sound enhancing. These mufflers are capable of extremely low back pressure, even when used to silence, and are capable of extraordinarily pleasing tones when used to enhance engine sound. Furthermore, a resonance generating muffler has additional advantages such as:
         Providing a crisp, natural tone.   A lack of annoying low frequency “drone”.   The potential to reduce or eliminate popping exhaust sounds.   The potential to specifically reduce unpleasant tones without sounding dull and artificial.   The ability to solve the problem of high back pressure (and its consequential reduction of efficiency) in mufflers intended to silence.       

     Although the above description provides many specificities, they should not be construed as limiting the scope of the invention or its embodiments. Rather, these specificities should be seen merely as examples of what is possible under the claims. Many other variations are possible as well. For example, any body shape may be used. In addition, any number of elongated members may be used, in any combination or form, as long as they fall under the description in the claims. Any combination of sound baffles, sound absorbent material, and/or other sound altering devices (for example, active electronic noise canceling) may be used in addition to the members, providing such implementation is legal under intellectual property law. 
     Accordingly, scope should be determined not by the examples given, but by the appended claims and their legal equivalents.