hich woods are used for the construction of acoustic guitars?

The quality of the woods plays a fundamental role in the construction of an acoustic instrument. As for electric instruments, different woods are used for the body, the neck and the freatboard. Each one has peculiar physical, sonic, and esthetical characteristics, and costs can range widely depending on the quality of different tonewoods. Wood seasoning is very important: green wood does not have satisfactory sonic qualities and will certainly shrink during the natural process of seasoning. As other factors, like the kind of wood grain (open, closed, even, uneven), the seasoning, the bracing system, all influence the final sound of the instrument, the type of wood is just one among the many aspects contributing to the global sound. In other words, it is not possible to predict precisely how a guitar will sound knowing only the woods used. Our classification of woods will be based on their use, that is, the wood used for the top (or soundboard), and those used for sides and bottom.

The top (or Soundboard)
Spruce and cedar are the most frequently used woods for the soundboard of an acoustic guitar.

Spruce
This is the most common wood used for the tops, it is highly resonant, and has a well balanced and bright tone. Usually light coloured, the sound improves over the time, as spruce wood changes during the life of the instrument. The different kinds of spruce used for soundboards are:

• Sitka spruce: highly resonant, clear, crisp and full tone, with a bright mid-range. The dense and even grain guarantees a fast response. It is the most used spruce.
• European spruce: less aggressive sounding than the Sitka, shows a very well balanced tone, with more rounded mids and lows and particularly harmonically rich. Renowned for its resonance (especially the timber coming from central and east areas), it is preferred for finger-style and is used for the construction of pianos and violins too.
• Englemann spruce: its sound is very close to those of the most expensive spruces (red spruce or Adirondack), with a more prominent bass and marked mids, together with the classic brightness of the spruce on the higher frequencies. Compared to Sitka, offers a faster response and sounds louder. Very appreciated for finger-style and flatpicking.
• Red spruce (Adirondack): the favourite spruce by collectors, very rare and valuable. Combines the snappy attack of the Sitka with the harmonic complexity of the European spruce, with a fast response due to greater elasticity. The best choice for flatpicking, and by all accounts the only spruce able to recreate the vintage sound of the famous guitars built before the 40’.
• Douglas spruce: very similar to Sitka spruce, but with a more rounded tone. Very well balanced sound and a very fast response.

Stika Spruce

Cedar

The wood used as an alternative to spruce is cedar. Cedar sounds more rounded, softer and warmer than the spruce, that on the other hand offers a more opened and brighter tone, with more definition and loudness. That’s why we say “cedar is for the players and the spruce is for the listeners”. Moreover cedar does not change with the passing of time, consequently its tonal qualities will not improve during the life of the instrument as often happens with spruce (according to someone, cedar looses part of its global richness, but this is not always the case). Aesthetically, the difference between spruce and cedar is obvious, the latter being darker and reddish. Broadly speaking, who is looking for a more aggressive sound can usually prefer the spruce, but this is true only if other construction feature are the same. As a matter of fact, the sound of the guitar is also influenced by the shape, the bottom, the sides and the brace. For the soundboard of acoustic guitars, the Spanish cedar is preferable, usefully combined with rosewood, ovangkol or walnut sides. Sonically can be compared to sitka spruce, but with less transparency and harmonic separation. The red cedar is more suitable for the classic guitar, but can be a good choice for acoustic instruments used for finger-style, thanks to its bass-focused tone but nevertheless bright sounding at the same time. To express its tonal qualities at their best, red cedar must be cut into thin boards, consequently it is suitable for guitars equipped with thin gauged strings.

Spanish Cedar

Bottom and sides
The most common woods used in the construction of bottom and sides are rosewood and mahogany. Maple is frequently used too, mainly because of its beautiful figures, and the open and loud tone. Other tonewoods more rarely used for bottom and sides of the acoustic guitars are the ovangkol, the koa, the zebrano, the walnut (just to mention some).

Rosewood

It is a valuable and expensive wood (especially the Brazilian one), very strong and heavy. This translates in a warm and rounded sound, together wit a long sustain, qualities that make it suitable for flatpicking and bluegrass guitars. Especially beautiful, with noticeable grain and brownish coloured.

The Indian rosewood, less valuable than the Brazilian one for availability reasons (but sonically equivalent or even superior) shows more porosity, a darker colour, and less noticeable grain, that looks more even and parallel.

Indian Rosewood

Mahogany

Mahogany is lighter and usually less expansive than rosewood. Aesthetically has a typical red colour, sometimes with valuable figures. Broadly speaking, an acoustic guitar with mahogany bottom and sides sounds usually more sweetly and focused on the mid frequencies than a guitar with rosewood bottom and sides. Mahogany guitars are preferred by musicians using the bottleneck technique. Some acoustic guitars are entirely built in mahogany, often combined with an open pore or satin finish.

Mahogany

Maple

Maple is widely used for electric instruments (for the necks, fretboards, tops and bodies), but is suitable for the bottom and sides of acoustic instruments too, even if more rarely used than rosewood or mahogany. It is a beautiful wood, with its many aesthetically appealing variances. As maple highlights the higher frequencies in the spectrum, it is often employed to balance those instruments that would otherwise sound too rich in the low end, like the Jumbo models, for instance. A guitar with a maple body, even if with a poorer tone in the low end, will project a loud sound, perfectly suitable for the typical rock strumming.

Moreover, maple offers a beautiful aesthetical addition to any guitar, thanks to its many figures, like quilted, flamed, tiger, bird’s eye, curly, or spalted.

Laminated or solid woods?

In the construction of the acoustic guitar, the woods used can be solid wood (that is, made from a single piece of wood) or laminated wood, in which thin sheets of wood (usually at least 3) are glued on top of each other so that the grain of each layer is crossed, to increase strength.

This reflects in the propagation of sound, that depends on two factors: elasticity of the materials the instrument is made of, and its weight. As solid wood is lighter and more flexible than laminated wood, the propagation of sound waves is better when a guitar is built with this type of woods. On the other end, laminated wood is heavier and less flexible, but is stronger. Moreover, the sonic qualities of solid wood improves over the time, while those of laminated wood remain stable.

Both the top and the soundbox (bottom and sides) can be made of solid or laminated woods. The entry level models are made of laminated wood to keep costs down, while higher quality models can use solid wood for the top, the soundbox, or the entire instrument. Many guitars use a solid wood top together with bottom and sides made of laminated wood, in order to combine decent sound quality with strength and lower costs. This is not always true, as a low quality solid wood could sound not as good as an high-quality laminated spruce, for instance (spruce is the best sounding wood in terms of resonance, consequently is the most used wood for the soundboards). We want also remind that a solid wood guitar is easier to repair, as solid wood cracks, while laminated wood breaks into pieces.

The most important elements we must take into account when choosing solid or laminated wood are:

• Tone and resonance (solid wood is clearly superior if beyond entry level performances are needed, at least for the soundboard)
• Applications (for a guitar often used outdoor, that travels frequently, bottom and sides made of laminated wood can be preferable for their strength)
• Budget (solid woods are more expensive)

The Soundsation line of acoustic guitars includes models made entirely of laminated woods and models wit a solid wood top.
Series using laminated wood: Yosemite, Yellowstone

Series with solid wood top: Shadow, DN, CNE