Thanks for visiting.  I think you'll find this site very interesting.
                  Frank Geiger

Musical Surface Acoustic Wave Toolkit #1

First, I Would Like To Introduce Myself

     I'm a retired Army Officer, former sales person of computer aided design and manufacturing systems and computers, former college instructor of mechanical design engineering and mathematics, and, more recently, former musical solo entertainer with tenor banjo and vocals in the Atlanta, Georgia area for 26 years.  That's my picture on the right holding a 1927 Paramount tenor banjo.  For the last 10-15 years or so I've spent a lot of time trying to improve the sound of banjos, guitars, mandolins and violins with my own inventions on my own instruments, and it was during this period that I began to teach myself, through experiments, about musical surface acoustic waves.  During this time I patented six of my inventions and tried to sell them to my fellow musicians, but recently gave up that idea in favor of sharing what I've learned about musical surface acoustic waves, both over this website and, God willing, in a book which I have just begun writing.

     
     This section, "Musical Surface Wave Toolkit #1", includes the approach that I have used to make surface acoustic wave devices for most popular acoustic stringed musical instruments.  Following sections describe specific devices for guitars, banjos, mandolins and violins in sufficient detail for you to make the devices for yourself or, if you are so inclined, for you to sell.  All devices are temporary, movable attachments which should not damage the instrument when constructed by design and used properly.  All of the designs are in the Public Domain. It should also be mentioned that everything described as a "fact" should be considered an "apparent fact" based on my observations during experiments and is offered without proof.  

      The next paragraph, "The Big Picture", is the first "tool" in the toolkit because it describes the goal and the method to be used to achieve it.

     The Big Picture


     Assumption:  When a musical instrument is played all surfaces of the instrument are covered in varying degrees with surface acoustic waves.  These waves can be copied (or "picked up") by placing them in contact with a material which is easily deformed in the shape and timing of the surface acoustic wave to be copied.  Such materials include some acrylic tapes, threads, waxed, braided cords, and thin shapes of metals, woods and papers.  

     Experiments have shown that these surface waves are accurate representations of the music we hear from the instrument, and that the surface waves can be "improved" by amplifying harmonics in the music (multiples of the fundamental tones in the music) which improves sound quality.

     Waxed, braided nylon cord has proven to be ideal for this purpose because the braids of fibers intersect at an angle which causes waves on those fibers to intersect at an angle.  This intersection of waves at an angle causes therm to amplify multiple times down the length of the fibre, (by "Constructive Interference" as defined earlier). This amplification can be increased by compressing the braided fibers, which causes  morem waves to intersect and amplify waves on more fibers.  Waxed braided cord also has the advantage that it causes minimum distortion to the instrument's sound producing waves on the edge of its sound opening when it is necessary for the cord to enter the sound chamber, such as through the through the sound opening of guitars.