A narrow grain top will have comparatively stronger treble and more subtle bass:
The exceptional tone produced by a great guitar, results partly down to the type of woods that the it is made from. Different woods have their own distinctive voice, and influence how the instrument will sound. Although there are many other factors that will govern the overall tone, such as how well it is made and obviously how it is played, the characteristics of the wood help to bring out the tone of the instrument. Most manufacturers believe that the top is the most important determining factor in the quality of the sound.
Laminated v Solid Top
The front, back and sides of acoustic guitars can be made from different combinations of laminated or solid woods. The top material is generally considered to have the greatest effect on sound quality, and so a solid topped instrument with laminated back and sides will probably sound better than an all laminated one. The quality of sound increases the more solid its materials, and so ones with a solid top, back, and sides should give rise to the best quality sounds. Solid bodies also last much longer and can even increase in sound quality as the woods mature with age.
Solid Top
These are made from two solid sheets of wood to form each half of the sound board (You can usually see a line running down the middle of the face which is the join between the two).
Laminated Top
These consist of several pieces and layers of wood that have been laminated together to form the sheet. Because a solid top will have long continuous grain lines in its structure, solid- topped soundboards produce a clearer tone and will last much longer than a laminated top. A laminated body has multiple grain layers running in different directions, which will not vibrate as well and will deteriorate over time as the layers loosen.
The following is a description of the characteristics of different types of solid wood used for guitars and other strung instruments.
Spruce
The most commonly used material for the top is Spruce. It has a rigidity that enhances the tonal clarity, especially when the instrument is played hard. There are different varieties of spruce with slightly different characteristics.
Sitka spruce
North American solid Sitka Spruce produces a loud and balanced voice with a strong fundamental (lowest frequency harmonic). Sitka tops are sought after by players with a strong attack due to their crisp treble bite.
Engelmann Spruce
North American solid Engelmann Spruce is a beautiful rich, creamy soundboard wood. Spruce enhances volume and has clear high-end articulation. Engelmann adds a brilliant complex overtone structure. Widely regarded as the best tops you can get.
Cedar
Cedar has a darker colour to Spruce and can have a reddish tint. This wood is highly responsive to light playing and fingerstyles, responding with volume to a softer attack, for this reason it is most commonly found in instruments with smaller bodies, classical and folk guitars. Cedar is most notable for its response to open and lowered tunings.
The voice of Western Red Cedar is characterised by a dark, rich and smooth tonality. As with all Cedar, it is especially responsive to musicians with a lighter touch and fingerstylists.
Indian Rosewood
One of the world’s most prized woods for instrument backs and sides, Indian Rosewood looks stunning, with a thick and darkly banded grain. Indian Rosewood gives rise to a complex, warm and deep tonescape. Its effect can differ depending on whereabouts in the guitar it is. It can be especially good at producing singing harmonics.
Brazilian Rosewood
The high sound velocity and overtone range of Brazilian Rosewood gives it a bright treble and clear low-end response. The inherent resonance of the Rosewood produces a singing tone, darkened by the strength of the bottom end.
Mahogany
Mahogany can help to enhance the tone and stability of an instrument in combination with a good quality solid top. Mahogany is generally used for the backs and sides where its strength helps contribute more treble and bass to the overtones. The sturdiness of Mahogany makes it especially suitable for neck construction.
Sapele Mahogany
Sapele Mahogany has a bright striped grain and is clear and responsive. Both beautiful and brilliant, Sapele is an excellent tone-wood for back and sides. Similar to Mahogany, but cheaper.
African Mahogany
Also known as Khaya Mahogany, its interlocking grain contributes to strength and stability as well as creating a flowing, patterned appearance.
Pau Ferro
Many people have only become aware of this wood since its being more widely used due to CITEs laws on Rosewood but Pau Ferro has been the fretboard for the Stevie Ray Vaughn Strat for years. It has a warm tone yet with a nice amount of attack, giving clear definition and similar oil content to rosewood.
