New Invention: Amplifying Sound Surface Wave Waveguide

Two weeks ago I submitted a provisional patent on a new invention that greatly improved the sound of my open back Irish tenor banjo and fiddle, and held promise to improve the sound of mandolins and guitars as well.  (I play American style chord melody solo tenor banjo (CGDA), Irish style (single string) tenor banjo (GDAE) and Irish style fiddle.)  Since the neck on my mandolin had broken a few months ago when it fell in its soft case I purchased a very inexpensive mandolin last week (a Style A "Kentucky") - primarily so that I could test the new invention on it.  I finally got around to the test this morning.  The result was amazing!  - Tremendous volume and wonderful sound quality in all notes and especially the highs.  I'll describe this new device here and will shortly offer it for sale as a component to a new mechanical amplifier product for mandolins.

The new invention is an amplifying sound surface wave waveguide.  That name probably doesn't mean much so I'll briefly describe what it does.

For several years I have offered a series of products for fretted instruments called mechanical tone amplifiers.  These mechanical attachments were simple gadgets which took sound surface waves (inaudible mechanical ripples on the surface of the instrument analogous to the music), usually from the vicinity of the sound opening, and converted them into audible sound in air in the sound chamber of the instrument.  The problem with this approach was that the strength of the instrument's sound surface waves was limited to those next to the sound opening.  So the obvious question was, "What would the same gadget sound like if input sound surface waves could be taken from the bridge, or the area of the top next to the bridge - or from any other location on the instrument where surface waves were especially strong?"  That question is what started our experiments with sound surface wave waveguides.

In addition to carrying sound surface waves from wherever they are strong to the sound chamber, our new waveguide does one more very important thing - it amplifies the surface waves as they flow over (and through) the waveguide before they reach the audible sound emitter in the sound chamber.  The waves are amplified A LOT!

The new waveguide looks like a plastic coated wire about 6-inches or so long that goes from the vicinity of the mandolin bridge to and through the mandolin's sound opening to the audible sound emitter in the sound chamber.  A small bit of clear plastic tape attaches it to the end of the bridge, or behind the bridge, or wherever the wave guide can reach and not be in the way of the player's hand.   The plastic coating on the waveguide is actually a surface wave amplifying spiral wrap of sound surface wave conducting tape.  The core of the waveguide inside this spiral wrap is a special construction of two very small steel wires which repeatedly amplifies the surface waves as they flow over the pair of wires.

Also attached to the waveguide, with a bit of tape and not far from the bridge, is a very small "tone piece" (also patent pending) which adds wood or metallic timbre and well as additional amplification.  The player can change the timbre off the mandolin's sound using different tone pieces.

I plan to offer the waveguide as a part of an improved tone amplifier for mandolins which will include an assembly of the waveguide, sound emitter and attached tone piece (for easy installation), plus a selection of different tone pieces, extra tape and illustrated instructions.  The price will probably be around $20 plus postage.  The announcement will be posted on our website, (see the link at the left), when everything is ready.

In the meantime I will be learning about it by playing my mandolin with the new waveguide at Irish sessions along with my banjo and fiddle.  I can hardly wait to hear the reaction of my session mates when they hear my mandolin "screaming" music!

Wonderful New "Tone Brightener/Amplifier/Enhancer" for Inexpensive Banjos