Types of woods for classical, flamenco, acoustic and electric guitars
When buying a wooden guitar, many people get carried away by the manufacturer's brand name and few pay attention to the types of guitar woods used. However, what most influences the sound and quality of these instruments are their construction materials. These determine not only the duration and resistance, but also the timbre, volume, and general quality of the sound.
Determining if guitar wood is good can be a bit tricky. It's not only about the types of trees, but also about the place where they were grown, the physical and chemical properties, the structure of the veins, among other aspects that must be taken into account. That's why, to clarify all your doubts, we have prepared this article. Here, you'll find all the information you'll need before buying an electric or acoustic guitar.
Table of contents
Types of woods for guitars
The classification of the types of guitar woods varies depending on the manufacturer. Generally, the selection and arrangement of materials for a wooden guitar is carried out by experts in materials engineering. These professionals must also have a broad knowledge of botany.
For example, Alhambra, the manufacturer of Spanish/classical and flamenco guitars, uses the most common of these classifications. It's important to note that there may be variations between each company. However, the basis of this system is basically the same and they all use these three criteria:
- Botanical type: refers to the type of plant or tree used in the construction of guitars. However, this criterion is also often accompanied by certain prejudices, because traditionally some plants are valued more highly than others, such as spruce versus cedar. This assessment is based on tradition alone and is not based on the characteristics that each wood offers.
- Country of origin: Luthiers tend to prefer woods from tropical countries and therefore these are more expensive. On the other hand, woods from European countries with temperate or cold temperatures are considered cheaper in a certain sense.
- Purity of parenchymal tissue: The molecular structure of plants is an element that is analyzed in the laboratory. This study is used to determine the quality of the joints between the layers of the fabric. It also determines the chemical integrity of the wood to know whether or not there are any agents or external agents that influence its molecular structure.
Physical and acoustic testing of guitar woods
These are the last stages in the grading process to choose the best guitar woods. To do this, samples are taken from different layers of the same trunk and analyzed in a laboratory to perform a mechanical characterization of that guitar wood. Subsequently, this characterization is compared with values already established for that specific type of wood and thus it is verified that it is within the normalized standards.
The mechanical characterization of guitar woods involves the determination of two groups of parameters, such as:
It involves the identification of wood bulk density and other elements such as hardness. One of four types of tests is usually used: Brinell, Rockwell, Chaláis-Meudon, and Vickers. The most reliable of the four is the Chaláis-Meudon test, but in many cases the Brinell is also used. Finally, to choose the best wood for a guitar, the tendency to curvature is determined.
Four parameters are determined:
- Flexural strength: how many lbs or kg of tension it is capable of withstanding when flexed at three points.
- Compressive strength test: determines how many lbs of pressure a material will withstand until it deforms toward its center of gravity.
- Tensile strength capacity: refers to the lbs of traction that a standardized piece of wood is capable of withstanding.
- Modulus of elasticity: indicates the elastic properties of wood.
All these tests are performed on standardized pieces of wood. That is, they are portions of wood that have a specific moisture content, length, width, and depth. Another important factor is that they must not present defects in their structure, such as cracks, knots, colainas, eccentric heart, or hollow heart.
This is something that may vary depending on the manufacturer. It is usually subject to the criteria of the luthier who, depending on their training, may have some biases. The classification of the best woods for electric guitar, woods for classical guitar, woods for Creole guitars, or any other type of guitar, is as follows:
Type A or Class A guitar wood types for beginner guitars are almost always laminated. This means that they are composed of several layers that were glued together and therefore their sound quality is inferior.
However, the type of woods for guitars classified as Type A varies depending on the manufacturer and their quality standards. For example, Alhambra classifies some solid woods as Type A and uses them in its beginner guitars.
These are woods for conservatory and intermediate level guitars. They are always solid, with partially straight veins and the separation of these natural lines doesn't usually exceed 3 mm. They also have more stable vibrations, with better resonance and response to different sound frequencies.
They're used in professional level guitars, and their sound capacity is maximum. They're the best wood for guitars since they have a larger caliber, and that's why these guitars are heavier. Its response to vibrations is the most stable of all, and thanks to this, the advanced guitarist can find the desired sound.
These are guitar woods with the same characteristics as Class AAA but are exotic. They are appreciated above all for the aesthetic contribution they make to the instrument. These are the best woods for exotic guitars.
In addition to the above classes, some manufacturers add the ‘+' symbol as a transition between each class. For example, Class A+ would be a transition to Class AA, while Class AA+ would be a transition to AAA. They are of the best woods.
Most used types of wood
What is the best wood for guitars? Much is said about the types of woods for guitar and generally what predominates are preferences and ignorance. In general, these are the most commonly used woods in electric and soundboard guitars (classical/Spanish, flamenco and acoustic).
- The best wood for electric guitar: poplar, mahogany, ash, American basswood, maple, rosewood. Also Indian rosewood, agathis, walnut, meranti, New Zealand pine, sapelli, laurel.
- Less common electric guitar: panga panga, okoume, jatoba, bunbinga, nyaton, pau ferro.
- Most common in soundboard guitars: and the best wood for Spanish guitars: South American mahogany, African mahogany, spruce, walnut, spruce, meranti tembaga, nato, rosewood, sapelli, ebony, granadilla, cypress, agathis, tropical pine, nato, flamed maple.
- Less common acoustic guitar woods and flamenco guitar woods: Hawaiian koa, okoume, sycamore, ovangkol, ziricote, samanguila, Californian red cedar, cocobolo, olive, Canadian spruce, nazarene/purplewood.
The woods mentioned as less common are used in beginner, intermediate, advanced, and exotic/custom guitars. These are in many cases experimental or inexpensive woods, such as Hawaiian koa, okomune, and ovangkol. In other cases, they only serve aesthetic functions, such as cocobolo and nazarene.
The best exotic guitar woods, such as okomune and ovangkol, are used in Malaysian and Philippine factories because they're endemic to the area and this reduces production costs. On the contrary, woods such as cocobolo and nazarene are expensive, and the buyer ends up paying more for their aesthetic beauty than for their sonorous performance.
An example of this is nazarene, which happens to be one of the densest and most difficult woods in the world to work with. It has almost zero resonance, and even spruce laminated woods have better acoustic capabilities than nazarene. However, this wood is very popular because it cancels out unwanted sounds and gives priority to the frequencies of the soundboard, in addition to the undoubted aesthetic value it brings with its beautiful purple color.
This is also the case with cocobolo wood, whose acoustic value is almost nil working on its own. On the other hand, it's excellent when seeking to highlight the properties of other woods.
Best woods for electric guitar
It's important to note that these characteristics vary, albeit slightly, among different species of the same tree. This is due to the particular soil and climatic conditions of the country of origin, among other aspects. These are the most commonly used woods in electric guitars:
There are three species of poplar: Populus nigra cv thaisiana, P. alba var bolleana, and P. x canadensis conti. The average characteristics of these species are:
- Density: the three species have an average density of 0.35 to 0.45 g/cm3. This means that their woods are soft but with excellent acoustic properties.
- Hardness: being a soft wood, its hardness on the Janka scale is between 1.0 – 2.0 k/N. This means that it is not very resistant to shocks, but it is easy to work with.
- Bending: Poplar is not a very resistant wood to bending (46 – 62 N/mm2). Some manufacturers compensate for this by using a body composed of several layers of the same wood. Thus, the gluing and the compression to which it is subjected exert additional force.
- Compression: its durability also affects compression, which is 27 – 37 N/mm2. To overcome this, all manufacturers use resin finishing. This prevents dents.
- Tensile: this is the resistance of wood when two opposing stresses are applied to it. Unlike the other characteristics, we find that the values for poplar in this section are intermediate (4.7 – 4.9 N/mm2), which means that it resists a higher tensile strength. This is due to its elasticity.
- Elasticity: between 7600 – 9800 N/mm2. This is the main advantage of poplar, because it is very elastic, its vibratory capacity is quite large and can be used in combination with other harder woods.
North American linden
American Basswood (American Tilia) is most commonly used for models such as the Ibanez and Fender guitars, which are the best-selling guitars in the world. This indicates a certain preference for the sound of these brands, but is it due to the woods? Let's see:
- Density: it isn't the best characteristic of this wood, because it only has an average density of 417 kg/cm2. It is therefore classified as a light wood and not very resistant to shocks.
- Hardness: perhaps this is the wood with the least hardness. It has an average of 1.8 on the Chaláis-meudon scale, so it is considered very soft. It is easy to work with and the paint adheres very well, but it is a sheet of paper in the face of knocks and therefore up to five coats of finish are often used to give it greater resistance.
- Flexion: it has a flexion similar to that of European walnut, with 955 kg/cm2. The main benefit of this feature is that it is more resistant to abuse than the use of floyd or tremolo.
- Compression: compressive strength is only 340 kg/cm2. Care should perhaps be taken not to leave heavy things on it to avoid deformation.
- Tensile strength: its average range is 970 kg/cm2, i.e., it resists very little.
- Elasticity: it has an elastic capacity of 68,000 kg/cm2. This indicates that its vibration capacity is low. Nevertheless, many musicians have a preference for these guitar woods.
In our article about Gibson guitars you can check the properties of mahogany, another wood widely used in electric guitars.
Alder, specifically Alnus glutinosa, is one of the most valued woods for the manufacture of electric guitars. This species is native to Europe and its import is one of the highest in the market because it grows quickly.
- Density: It's a semi-light wood, with 550 kg/cm2. Its value places it as an equivalent to European basswood and it's one of the best woods for electric guitars.
- Hardness: It has a hardness of 1.8 on the Chaláis-Meudon scale, like American linden. The rest of its properties differ considerably.
- Flexion: This characteristic allows it to have a better response to floyd rose, since its value is 800 kg/cm2. However, this will depend on the integrity of the wood. The fewer defects it has, the better it will be.
- Compression: Its compression capacity is medium (410 kg/cm2). The rest of its characteristics compensate and work to improve its resistance to fractures.
- Tensile: It's the wood with the lowest tensile value, having only 440 kg/cm2. This, instead of being a defect, results in a great benefit because it makes its elastic and, therefore, acoustic capacity possible.
- Elasticity: 115,000 kg/cm2, i.e., it's very elastic. As a result, its sound quality is top-notch, which is why it's so highly valued.
We will describe two species of walnut: European walnut (Juglans regia L) and American walnut (Juglans nigra L). These, despite belonging to the same genre, differ in several of their characteristics:
- Density: both European and American walnut have medium-heavy woods. Their density is 650 kg/m3 and 610 kg/m3 respectively.
- Hardness: European walnut has a value of 3.8 and American walnut 3.6 on the Chalais-Meudon scale. This means that they have semi-hard woods. This difference in the hardness of the two species is due to the different temperatures at which they are grown.
- Bending: in spite of having a medium density, both species have a considerable bending capacity: European walnut with 970 kg/cm2 and American walnut with 1010 kg/cm3. This difference is minimal and luthiers usually choose the species that generates the lowest transportation costs.
- Compression: European walnut has a value of 590 kg/cm2 and American walnut 523 kg/cm2. This indicates that both have a fairly good compressive strength.
- Tensile: both European and American walnut have low tensile strength, with 970 kg/cm2 and 930 kg/cm2 respectively.
- Elasticity: both walnut species are very elastic (113,000 kg/cm2 for European walnut and 116,000 kg/cm2 for American walnut).
The differences between the two species of walnut are minimal. However, most luthiers tend to prefer hickory because its elasticity gives it a slightly higher vibratory capacity. In contrast, luthiers in the central European region, such as Germany, prefer European walnut. And not because it is cheaper, but because they prefer sounds with good attack but moderate sustain.
You can see other characteristics of walnut and many other woods in José Ángel Chacón Tenllado's book “La Guitarra en la Luthería “.
Now the big question is what are the best woods for electric guitar? For us, linden, alder and European walnut are very good choices. However, we are not in favor of imposing our preferences and we always opt for the musician to try, experiment with the different types of wood and decide which of them best suits his or her personality.
Best woods for acoustic, classical/Spanish and flamenco guitars
We will now look at the types of woods that are most widely used in the manufacture of classical/Spanish, flamenco, and acoustic guitars that are the most popular in the world, such as the Yamaha C40. For this purpose, we will only focus on cedar and spruce because they are the most important ones for luthiers.
For this section we have selected two species. On the one hand, Pacific red cedar (Thuya plicata D), considered Class AA+ and AAA. On the other hand, the common cedar (Cedería orodata L), classified as A and AA.
- Density: there is a considerable difference between the two species, with 370 kg/cm3 (Thuya plicata D) and 590 kg/cm3 (Cedería orodata L). The first is a select wood, with a balanced acoustic capacity.
- Hardness: the difference in hardness is also notable: 1.3 (Thuya plicata D) and 2.0 (Cedería orodata L) according to the Chaláis-Meudon test. Both are considered softwoods, but the quality grading is in favor of the softer one.
- Flexion: both species of cedar are highly flexible (530 kg/cm2 for red cedar and 753 kg/cm2 for common cedar).
- Compression: red cedar has a compressive strength of 310 kg/cm2, while common cedar resists up to 415 kg/cm2. That is, common cedar has a medium strength, while red cedar does not do very well in compression.
- Traction: these woods do not apply for traction tests because they are so soft.
- Elasticity: although they are not the most elastic woods in the world, they perform well in this aspect. Red cedar reaches values of 80,000 kg/cm2, while common cedar is slightly more elastic, with 90,000 kg/cm2.
Cedar type guitar woods are generally used for the manufacture of the soundboard. The most important thing for this part of the guitar is flexibility and elasticity, because its main responsibility is resonance. Cedar comes in handy as it is a soft and highly flexible wood.
However, the main difference between the two types of cedar is found in the veins of the parenchyma tissue. In Pacific red cedar, the veins are very close together, approximately 1 mm apart. In common cedar the separation between veins can exceed 2 mm. This difference is vital for sound stability: the closer the grain is together, the better the acoustic quality of the wood.
The most valued spruce species is Picea abies Karst. Its origin is mainly Spanish and since the 15th century it has been a favorite wood for the construction of guitars and chamber music instruments.
- Density: it is an intermediate between the cedar woods described above, having a density of 450 kg/m3. This implies that it is light, with many pores within the parenchymal tissue and therefore retains sound quite well.
- Hardness: on the Chaláis-Meudon scale it is 1.5. It is therefore classified as a soft and elastic wood.
- Bending: its bending capacity is 710 kg/cm2.
- Compression: in this aspect it is slightly superior to cedar, with 450 kg/cm2. This implies that the sound has the tendency to move more towards the center of the wood, where the soundhole is located.
- Tensile: this wood is not applicable for tensile tests because it is so soft.
- Elasticity: in terms of elasticity, spruce is far superior to cedar, with 110,000 kg/cm2. A guitar with this wood is more vibrant, or at least this is what can be concluded from the data provided by the software during the acoustic test. Some luthiers claim that cedar is more resonant, although in the light of tests this is not true.
The favorite guitar wood of luthiers is spruce for almost all musical instruments that work with a soundboard. Although we prefer cedar because of its stability, because we like the pasty sound, with long lasting harmonics and stable volume.
Acoustic ratio between guitar woods
Beyond what is believed, the types of guitar woods used for the manufacture of guitars have very particular characteristics that vary according to their species and country of origin. Some of the factors that most influence the acoustics of guitar woods are:
- The soils where the tree was grown.
- The chemicals with which it was treated.
- The time and year when the tree was felled.
These elements create differences in guitar woods of the same type. Despite the standard that exists in the manufacture of these instruments, some professional guitarists report noticing differences in the sonic response of identical guitars.
This is confirmed by experimental evidence. In identical guitars of the same model, it is possible to find weight differences of approximately 7%. There are also variations in modal frequency close to 9% and in modal damping greater than 35%.
Characteristics and differences between the most commonly used guitar woods
- Walnut has a more stable sound response.
- Mahogany tends towards low and medium frequencies.
- Alder is equivalent to walnut, but with less stability.
- Low density guitar woods are used in the manufacture of electric guitar bodies because they are more stable.
- Modal frequencies in walnut reach 3675 Hz, while ash reaches 3573 Hz. This means that walnut has a better response.
The following image shows the response between ash and walnut. We note that walnut is walnut and ash wood is ash.
The previous image shows that ash has a higher bending frequency than walnut (923 Hz vs. 748 Hz), which means it has more volume or attack when played. In contrast, walnut has a higher modal frequency (3675 Hz vs. 3573 Hz), which indicates greater stability and sustain when used as a guitar wood
Influence of harmonic bars on sound quality
This is perhaps the most widespread myth when talking about the types of woods for classical/Spanish and flamenco guitars. Luthiers are the main disseminators of these myths, and this is largely due to a lack of knowledge about the scientific data on the subject
We must say that the influence of harmonic bars on sound improvement is very low at best. They simply distribute the sound in a different way through the soundboard.
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