Almost as important as the design of the guitar is the acoustics themselves, which is enabled and enhanced by the types of materials, design and relatively important manufacturing secrets and construction features.

For the most part, three main features are identified that contribute to these characteristics of the guitar. They are

Coupling
Material Composition
Plate Bracing


The term coupling is referring to when two vibrating objects, surfaces and patterns connect, intermingle and vibrate together, absorb and resonate. Energy displacement,  from the source or impetus for the sound, namely plucking a string with your finger (or picked, strummed) the sting and bridge vibrate, stimulating the soundboard, traveling as airwaves and vibrations into the internal air cavity, of the guitar, travels around inside the sound-box, vibrating against the sides and back and keeps on going. If the components, individually and collectively work and connect, resonate and sound good, vibrate together, great music is to be made from and with it. When all the individual elements and sound wave patterns work well together, guitar is in tune, then the system is said to be coupled together and working well.

The  guitar sound-box or body, actually acts as a channeling avenue for the sound, converting high pitch, high pressure vibrations at the bridge into low pressure vibrations in the surrounding air. It matches "impedance�. Higher sounds are created through stings and bridge, soundboard flow. Lower sounds are created through internal 

The higher frequency (pitch) sounds are produced by string interaction with the bridge and then the sound board, whereas the lower frequencies are essentially driven by the internal air cavity/sound hole and ribs/back coupling effects:

How the vibrations flow, can also give some resonance frequency and how the strings are played can also have an effect or secondary influence on what the sounds will actually be.

Coupling between the different guitar parts will depend on a couple of factors, like which kinds of material are used, where they are places, math/geometry principles and the science of sound and frequency, resonance and playing techniques.

How these different parts come together is almost similar to how instruments play together in an orchestra, each having its part to play, forming a beautiful, resounding symphony of sound, song and music! If there is too much �coupling� sounds will be harsh-sounding and not pleasant on the ear, despite best-effort tuning.

Construction, materials and resonance symmetries, as well as bracing , even how the sides and top/back plates are connected, bridge type and placement, even glue or adhesive will all affect the final tone and sound-quality of the instrument.  Sound-holes are resonators of the created sounds.  Acoustics are also dependent on material Composition (more on that later).

Labels: Accoustic Guitar, Guitar, Instrument, Music

Posted by Scott S | 2 comments