ACOUSTIC GUITAR'S WOODS

Mahogany	When used as a top, mahogany has a relatively low velocity of sound (compared to other top woods), considerable density and a low overtone content producing a solid tone, and responds best at the upper end of the dynamic range. Mahogany-topped guitars have a strong "punchy" tone that is well suited to country blues playing. When considered for back and sides, mahogany has relatively high velocity of sound, which contributes much overtone coloration. While rosewood guitars may be thought of has having a metallic sound, mahogany guitars sound more wood-like. The harder, denser examples of these woods can take also on the characteristics of the rosewoods. Mahogany back and sides tends to emphasize the bass and the treble. Mahogany necks help to create a warmer, more "woody" tonal range. The same holds true when mahogany is used as bridge material.
Koa	Koa has been used for soundboards since the1920s. This hardwood has a relatively low velocity of sound, considerable density and a low overtone content. Therefore, it tends to produce a solid tone that responds best at the upper end of the dynamic range. Koa has a somewhat more "midrangey" tone that works well for playing rhythm and truly shines in guitars made for Hawaiian-style slide playing. For back and sides, Koa tends to behave much like mahogany in terms of adding tonal coloration, but its emphasis is again more in the midrange.
Brazilian Rosewood	All the rosewoods contribute to tonal coloration. Brazilian rosewood is known for its high sound velocity and broad range of overtones, and is also characterized by strength and complexity in the bottom end and an overall darkness of tone in the rest of the range. Strong mids and highs also contribute a richness of tone to the upper registers. Rosewood guitars also have a pronounced reverberant-like tone quality, caused by audible delays in the onset of certain harmonics. Brazilian rosewood has tremendous clarity in the bottom end and sparkle in the top. When used for necks, Brazilian rosewood adds sparkle and ring.
Indian Rosewood	Indian rosewood is also known for high sound velocity and broad range of overtones, strength and complexity in the bottom end and an overall darkness of tone in the rest of the range. Strong mids and highs also contribute a richness of tone to the upper registers. Indian rosewood has a thicker, more midrange overall coloration. When used for necks, Indian rosewood can help fatten up the midrange.
Sitka Spruce	Spruce is the standard material for soundboards, the most commonly used species being Sitka. Its high stiffness combined with the lightweight characteristics of most softwoods, makes it a natural for high velocity of sound. A strong fundamental-to-overtone ratio gives Sitka spruce a powerful direct tone capable of retaining its clarity when played forcefully. This makes Sitka an excellent choice for top wood for players whose style demands a wide dynamic response and a robust, meaty tone. On the other hand, the lack of complex overtones in Sitka can produce a somewhat thin sound when played with a light touch - of course, depending upon the design of the guitar and the other choices of wood in its construction.
Red Spruce	Red spruce is relatively heavy, has a high velocity of sound, and the highest stiffness across and along the grain of all the top woods. Like Sitka, is has a strong fundamental, but also a more complex overtone content. Tops produce the highest volume, yet they also have a rich fullness of tone that retains clarity at all dynamic levels. In short, red spruce may well be the Holy Grail of top woods for acoustic steel-string guitars.
Maple	Maple, as a result of its greater weight and lower sound velocity, can be downright flat sounding, a blessing in disguise when a guitar is amplified at high sound pressure levels. This is why maple is the wood of choice for electric guitar tops. West coast big leaf maple is the softest and lightest of the maple family, with a wood grain that resembles waves. Aside from a visually breathtaking pattern, the wavy fibers of "curly" maple reduce the long grain stiffness and vibrate more freely. (This is the secret to the bright, clear powerful sound of the Parker Fly, a solid-body guitar made with a curly maple body.) In acoustic guitar use, different species of maple, such as big leaf, sugar, and bearclaw tend to be more acoustically transparent due to their lower velocity of sound and high degree of internal damping. This allows the tonal characteristic of the top to be heard without the addition of significant tonal coloration. Maple necks can impart a bright "poppy" tone that can do much to reinforce the top end of a large-bodied guitar.
Alder	Alder is a lightweight wood that is highly resonant, producing a full rich tone. When used for solid-body construction, alder provides a very good low end and midrange with the best performance in the lower mid range. Alder also exhibits good high-end characteristics and sustain.
Poplar	Poplar is a stringy, dense, yet lightweight hardwood that is unusually resonant. Poplar, when used in solid-body electric guitars, has an exceptionally crisp sound, often described as "spirited" and "bouncy" - even "funky." Poplar guitars are ideal choices for players who favor single-coil snap and clean sound.
Basswood	Basswood is light, stiff, and stable, which makes it particularly effective for necks and bass instruments thanks to its excellent low- end response.
Ebony	Ebony, the traditional material found on the necks of violins, classical guitars, and high-end steel strings, has the lowest velocity of sound of all the woods commonly used and has definite damping characteristics. While not a problem for large-bodied guitars made of red spruce or Brazilian rosewood, it may be something to consider when designing smaller guitars, particularly those using less resonant tonewoods for tops and backs.