Acoustic Guitars: How Construction Influences Sound
How guitars are made, affects the sound that is created and also affects the price of the guitar. Pick up any guitar and it is easy to see how the construction methods and materials affect the sound quality.
The most common type of wood that is used to create a guitar is center-cut hardwoods. There is a lot of concern about conservation in the guitar making industry so many of the woods that are used come from companies that promote sustainable forestry. But no matter what type of hardwood is used, it affects the sound that is created. Where the tree comes from, how it is processed and even the age of the tree all affect the final sound of the guitar.
Though some guitars have been made using polymers such as fiberglass and carbon fiber, which are also used in the construction of several other instruments, wood is still considered the best material. The quality of all the materials used is very important to get a great sound. Most guitar connoisseurs will only used guitars made purely of wood as these create the best vibrations and therefore the best sound.
It is important to know how the polymer products have a negative affect on the sound produced from the guitars. They do not create the right damping, elastic modulii or stiffness-to-mass ratio. The lateral to longitudinal grain properties that are found in guitars are also an important factor in creating a good depth of sound and timbre. However, these synthetic materials can be added as complements and can make the guitar more esthetically pleasing. Carbon fiber strut reinforcements can also add quality to the sound board. As long as synthetic materials aren't used for base materials they can actually help to improve a guitar.
The plate bracing is important because it affects how the guitar radiates sound. The plate bracing includes the sound board and the back plate which can often be very thing. This design comes from Antonio de Torres Juan (1817-1892). However, recently Greg Smallman has created the crisscross lattice bracing which is tapered outward. This is where geometry is really important. There are different variations on how the guitar is constructed. Whether the design is symmetrical or not affects the sound as well as the properties of the wood, the other materials used, and the placement of each piece.
It is easy to see how the construction, design and materials of a guitar affect the overall sound. Initially it is the actual wood that affects the sound where the main factors are the type of wood and how it is harvested and treated. Then the guitar has to be constructed. The placement of each piece needs to be determined and how the pieces will be attached needs to be determined. The other additional synthetic materials that are added as complements are the final piece that affects the overall sound.