In my previous posts, I discussed several aspects of qin making, ranging from the process, to personal thoughts and experiences, to some important design considerations. In this post, I would like to discuss wood selection, specifically relating to alternative wood choices for the top and bottom boards for the qin, and comparing them with the traditional wood choices.
You will find that there are generally less choices available for woods for the top board versus the bottom board. There are a tremendous amount of usable woods for the bottom board, and I certainly cannot list all of them here, but will present several major choices that would make great candidates for qin backboards (if catalpa is the most widely used and traditional choice for a qin back, then most woods harder than the top board can be useable, although there are certainly better choices than others in terms of color, grain pattern, and stability.)
For each wood, you will find data, which is sourced from The Wood Database, as well as a description with some thoughts for each. The Wood Database is an awesome website, and one that I regularly refer to for data on woods when making design choices for instrument building. It has an incredible wealth of information, and is an extremely valuable resource for any craftsman, woodworker, or instrument maker.
Generally the most important number to look at for woods for instrument making will be the average dried weight, the specific gravity, and the Janka hardness. While each piece even from the same species can vary a lot, these are average numbers which are generally well accepted and reported. For each section for top and bottom board wood selections, I will list the woods in increasing order based on Janka hardness.
TOP BOARD WOODS
Average Dried Weight: 18 lbs/ft3 (280 kg/m3)
Specific Gravity (Basic, 12% MC): .25, .28
Janka Hardness: 300 lbf (1,330 N)
Modulus of Rupture: 5,480 lbf/in2 (37.8 MPa)
Elastic Modulus: 635,000 lbf/in2 (4.38 GPa)
Crushing Strength: 3,010 lbf/in2 (20.7 MPa)
Shrinkage: Radial: 2.4%, Tangential: 3.9%, Volumetric: 6.4%, T/R Ratio: 1.6
Paulownia, as you are probably aware of by now, is the most common wood (pretty much used almost exclusively) for qin tops. It is not only an incredibly light wood, but very strong for its weight, and very resonant. While not particularly common or really used in the U.S., it is widely used in China, Japan, and Korea, and has made its way as the premier soundboard material for zither instrument in those countries: the guqin and guzheng in China, the koto and ichigenkin in Japan, and the gayageum and geomongo in Korea.
WESTERN RED CEDAR
Average Dried Weight: 23 lbs/ft3 (370 kg/m3)
Specific Gravity (Basic, 12% MC): .31, .37
Janka Hardness: 350 lbf (1,560 N)
Modulus of Rupture: 7,500 lbf/in2 (51.7 MPa)
Elastic Modulus: 1,110,000 lbf/in2 (7.66 GPa)
Crushing Strength: 4,560 lbf/in2 (31.4 MPa)
Shrinkage: Radial: 2.4%, Tangential: 5.0%, Volumetric: 6.8%, T/R Ratio: 2.1
Western red cedar is definitely one of the tonewoods that is associated with rich, warm, and mellow tones. In regards to general, average tone, western red cedar probably provides some of the warmest tonal properties for soundboard woods. I would say that western red cedar would be a great candidate as an alternative wood for a qin top. This could be great for either silk or metal stringed qin, to either enhance the warmth and depth of silk, or add a unique warmth and character to metal-nylon strings. This is certainly a wood that I would definitely like to try not only for future qin, but other stringed instruments I may build as well. It also has a very nice reddish-brown color to it, which can pair very nicely with other backboard woods and woods for parts like the bridge and nut.
Average Dried Weight: 25 lbs/ft3 (405 kg/m3)
Specific Gravity (Basic, 12% MC): .32, .41
Janka Hardness: 380 lbf (1,680 N)
Modulus of Rupture: 9,130 lbf/in2 (63.0 MPa)
Elastic Modulus: 1,406,000 lbf/in2 (9.70 GPa)
Crushing Strength: 5,150 lbf/in2 (35.5 MPa)
Shrinkage: Radial: 3.9%, Tangential: 8.2%, Volumetric: 12.9%, T/R Ratio: 2.1
One of the many available spruces used in soundboards for stringed instruments, mostly seen on instriments such as guitars, though not as commonly used as more popular spruces such as sitka spruce or engelmann spruce. Note that it is one of the softest spruces for use in soundboards. Despite being closer to paulownia in regards to specific gravity and hardness than something such as redwood for example, it is also still stiffer than harder and denser woods presented below, such as redwood and butternut, which may contribute to a more bright average tone, though not as much as stiffer and stronger spruces. Also note that it is less dimensionally stable than other woods such as paulownia or redwood.
Average Dried Weight: 24 lbs/ft3 (385 kg/m3)
Specific Gravity (Basic, 12% MC): .33, .39
Janka Hardness: 390 lbf (1,740 N)
Modulus of Rupture: 9,010 lbf/in2 (62.2 MPa)
Elastic Modulus: 1,369,000 lbf/in2 (9.44 GPa)
Crushing Strength: 4,560 lbf/in2 (31.5 MPa)
Shrinkage: Radial: 3.8%, Tangential: 7.1%, Volumetric: 11.0%, T/R Ratio: 1.9
One of the most commonly used spruces for guitar tops. Not as hard or strong as sitka spruce, but is still widely used and highly regarded in the spruce family for stringed instruments.
Average Dried Weight: 26 lbs/ft3 (415 kg/m3)
Specific Gravity (Basic, 12% MC): .36, .42
Janka Hardness: 450 lbf (2,000 N)
Modulus of Rupture: 8,950 lbf/in2 (61.7 MPa)
Elastic Modulus: 1,220,000 lbf/in2 (8.41 GPa)
Crushing Strength: 5,690 lbf/in2 (39.2 MPa)
Shrinkage: Radial: 2.4%, Tangential: 4.7%, Volumetric: 6.9%, T/R Ratio: 2.0
As I have mentioned in my previous posts, redwood is perhaps my all-time favorite topwood/soundboard material, not only for the qin, but for any stringed instrument. Not only is it available with exquisitely beautiful grain patterns, curl, burl, color, and figure, but is an exceptional tonewood. This is also the wood that I happened to use for my own qin.
Comparing it with paulownia, it is heavier and denser, as well as being a decent amount harder. When carving out the qin soundboard, you will need to take into consideration this increase in density and weight, and make slight adjustments accordingly. In regards to stability, redwood is extremely stable, with shrinkage numbers nearly the same as paulownia. The wood is also durable and resists rot well. Redwood has a noticeably lower modulus of elasticity than other tonewoods such as spruce, but this in part may play a role in its warmer more mellow tone. In regards to its warmth, it generally falls between cedar and spruce, though leaning much more to the cedar side of the scale.
There is a wide variety of options to choose from for redwood. Generally you can find either younger woods, or oldgrowth woods. The redwood is a protected species, and should only be harvested from already felled trees, so if you are looking to get redwood, make sure it is ethically sourced. While more expensive and difficult to find, oldgrowth redwood makes a much better tonewood than younger growth woods. It is also harder, heavier, more dense, and as the name suggests, older. Some of the best woods would be from sources hundreds of years old, from salvaged wood. Even more expensive are the figured pieces of redwood, which can fetch a very high price, especially for a piece large enough for a qin top. The curl in figured redwoods can make working with the wood a bit tougher, but the finished results are exceptionally spectacular. If you decide to use curly figured redwood for a qin that will be covered in opaque lacquer, you would certainly be committing a crime against this incredible wood, and may be subject to revocation of your qin/instrument making license!
Average Dried Weight: 27 lbs/ft3 (435 kg/m3)
Specific Gravity (Basic, 12% MC): .36, .43
Janka Hardness: 490 lbf (2,180 N)
Modulus of Rupture: 8,100 lbf/in2 (55.9 MPa)
Elastic Modulus: 1,180,000 lbf/in2 (8.14 GPa)
Crushing Strength: 5,110 lbf/in2 (35.2 MPa)
Shrinkage: Radial: 3.4%, Tangential: 6.4%, Volumetric: 10.6%, T/R Ratio: 1.9
Butternut is a lesser known wood, and one that I think deserves more attention as a soundboard wood for stringed instruments. Also known as white walnut, and in fact being a member of the walnut species, this wood is a unique option to consider for a qin top, or any stringed instrument top for that matter.
While not having super figured or fancy curl like higher end pieces of redwood, butternut does have a very nice grain pattern, usually likened to a “cathedral-like” pattern of alternating light and darker growth rings. I would say of the lighter colored woods, butternut is my favorite in regards to grain pattern and color. Butternut is widely known for having a beautiful creme color, and is sought after for carving. Butternut is a bit more difficult to find however, especially for very large single boards with the dimensions necessary for a qin top. On the flip side, it is also not terribly expensive, and still quite reasonably priced.
I have several boards stashed away of butternut that I am saving for a couple of Finnish kantele, another horizontal stringed zither instrument, part of the “Baltic psaltries” family of instruments found in Europe. I have also acquired a large piece of butternut that I used in the start of a guzheng build, but it remains incomplete as of now, and I have not worked on that project in quite a long time. Butternut, while still being a very soft wood, is harder and denser than both paulownia and redwood, the latter of which I used for my qin. Between the two, I would say that butternut certainly requires more effort to carve out than redwood on the underside, but for planing the top it’s about the same. I would definitely like to make a butternut-topped qin at some point however. I think tonally, this wood could pair excellently with walnut – I have in fact heard of a couple of guitars which used this combination very successfully. Butternut tonally is also a warmer sounding wood, though not as warm as western red cedar, and less bright than spruce, and could be a great middle-ground instrument, having potential balance between lows and highs. Note that its elastic modulus is one of the lowest in the list considering its average weight and hardness, so it will probably be less resonant and responsive than some other wood choices, but for a qin, this is not necessarily a bad thing, and could certainly enhance some unique tonal qualities inherent to the qin. It would also be pretty cool to use it even in a symbolic sense, as balancing out of yin and yang in a quite direct manner: the contrast in light and dark, soft and hard, of butternut and walnut, two similar yet different woods of the same family. It is certainly on my list of future qin woods to explore.
Average Dried Weight: 27 lbs/ft3 (435 kg/m3)
Specific Gravity (Basic, 12% MC): .37, .43
Janka Hardness: 490 lbf (2,180 N)
Modulus of Rupture: 9,580 lbf/in2 (66.0 MPa)
Elastic Modulus: 1,560,000 lbf/in2 (10.76 GPa)
Crushing Strength: 4,870 lbf/in2 (33.6 MPa)
Shrinkage: Radial: 3.8%, Tangential: 7.8%, Volumetric: 11.8%, T/R Ratio: 2.1
This spruce is extremely close in mechanical properties to sitka spruce, being only very slightly less hard. Being a high stiffness wood, this spruce, like other spruces, will exhibit a louder and brighter tone than woods such as redwoods or cedars. Often characterized as having a fast attack and clear tone, and considered an excellent tonewood.
CYPRESS (BALD CYPRESS)
Average Dried Weight: 32 lbs/ft3 (515 kg/m3)
Specific Gravity (Basic, 12% MC): .42, .51
Janka Hardness: 510 lbf (2,270 N)
Modulus of Rupture: 10,600 lbf/in2 (73.1 MPa)
Elastic Modulus: 1,440,000 lbf/in2 (9.93 GPa)
Crushing Strength: 6,360 lbf/in2 (43.9 MPa)
Shrinkage: Radial: 3.8%, Tangential: 6.2%, Volumetric: 10.5%, T/R Ratio: 1.6
There are many different trees that belong to the cypress family. This particular one is commonly referred to as bald cypress, and presents a interesting alternative as a soundboard material. It is not a common choice on “conventional” or more common stringed instruments such as the guitar, but I think it has great potential as a good sounding wood that is both very affordable, common, and has a bit more coloration and interesting grain than other lighter colored woods such as spruces.
You will notice that this wood much more resembles the mechanical properties of “brighter” woods such as spruce. I actually came across this wood in my journey in making the Finnish kantele, which is a stringed zither hailing from Finland, traditionally with 5 strings, but can range to over 30 strings with modern style instruments, using steel piano-wire strings, plucked with both hands. I wanted a brighter sounding wood that was a bit more interesting in color than spruce or the popular traditional wood for this instrument, birch. A lot of searching and comparisons led me to this wood – I have built 4 kantele using this as a topwood so far, and I am very pleased with the results. The kantele include a 5 string red oak frame and black walnut back kantele, two 8 string mahogany frame and curly hard maple back kantele, and a 5 string bubinga frame and wenge backed kantele. These builds also gave me a great look at how side and back woods can radically alter the tone of an instrument, even while using the same wood for the soundboard. As can be expected, the bubinga and wenge kantele is the brightest and most resonant, while the red oak and walnut kantele has a much warmer and mellow character. In any case, I think that bald cypress would be a great alternative to spruce if you are looking to make a brighter sounding qin with a more interesting grain, and is certainly much cheaper and easier to find.
Average Dried Weight: 27 lbs/ft3 (425 kg/m3)
Specific Gravity (Basic, 12% MC): .36, .42
Janka Hardness: 510 lbf (2,270 N)
Modulus of Rupture: 10,150 lbf/in2 (70.0 MPa)
Elastic Modulus: 1,600,000 lbf/in2 (11.03 GPa)
Crushing Strength: 5,550 lbf/in2 (38.2 MPa)
Shrinkage: Radial: 4.3%, Tangential: 7.5%, Volumetric: 11.5%, T/R Ratio: 1.7
Sitka spruce is one of the most common and well respected soundboard materials stringed instruments. It is used on many instruments, including violins, harps, pianos, and guitars, though may other spruces are used for these instruments as well. Sitka spruce has very high stiffness and strength, and is usually considered a “brighter” sounding wood than other choices such as cedar and redwood. This particular spruce also happens to be one of the strongest of the spruces, as well as one of the hardest. Note however that top quality boards of this wood will be expensive, especially for an instrument as large as the qin. This is certainly a tried and true instrument wood, but it does not necessarily mean it is the single best wood out there. While it has many great musical characteristics, there are many wood options out there to explore – personally for myself, since the wood is so often used, I find it a bit boring of a choice, and prefer the challenge of lesser used and conventional woods (I also prefer cedars and redwood, but this is again entirely my own personal preference.) However, it will certainly make great qin top, favoring brighter tone and louder volume.
Average Dried Weight: 28 lbs/ft3 (450 kg/m3)
Specific Gravity (Basic, 12% MC): .38, .45
Janka Hardness: 520 lbf (2,320 N)
Modulus of Rupture: 10,100 lbf/in2 (69.7 MPa)
Elastic Modulus: 1,523,000 lbf/in2 (10.50 GPa)
Crushing Strength: 5,410 lbf/in2 (37.3 MPa)
Shrinkage: Radial: 4.1%, Tangential: 6.8%, Volumetric: 11.3%, T/R Ratio: 1.7
Black spruce is nearly the same in terms of mechanical properties to sitka spruce, being on average only very slightly heavy and maybe stronger. It is however a smaller average tree in size than sitka spruce, so it may be very difficult to find a board the correct size for a qin, if possible at all.
ALASKAN YELLOW CEDAR
Average Dried Weight: 31 lbs/ft3 (495 kg/m3)
Specific Gravity (Basic, 12% MC): .42, .50
Janka Hardness: 580 lbf (2,580 N)
Modulus of Rupture: 11,100 lbf/in2 (76.6 MPa)
Elastic Modulus: 1,420,000 lbf/in2 (9.79 GPa)
Crushing Strength: 6,310 lbf/in2 (43.5 MPa)
Shrinkage: Radial: 2.8%, Tangential: 6.0%, Volumetric: 9.2%, T/R Ratio: 2.1
Though its name states cedar, this wood is not really a true cedar, but belongs more to the family of cypress trees. this is one of the hardest and heaviest woods presented here on this list, in comparison to other soundboard woods, though relatively speaking it is still very soft and light for a wood in general. Its tone is described as bright, lively, and responsive, with a character that is more similar to the spruces, but with a bit of its own unique flavor. It could certainly make a very interesting tonewood for a qin, and would be a great alternative to the spruces if you are looking for something with a bright tone but a bit different character.
AROMATIC RED CEDAR
Average Dried Weight: 33 lbs/ft3 (530 kg/m3)
Specific Gravity (Basic, 12% MC): .44, .53
Janka Hardness: 900 lbf (4,000 N)
Modulus of Rupture: 8,800 lbf/in2 (60.7 MPa)
Elastic Modulus: 880,000 lbf/in2 (6.07 GPa)
Crushing Strength: 6,020 lbf/in2 (41.5 MPa)
Shrinkage: Radial: 3.1%, Tangential: 4.7%, Volumetric: 7.8%, T/R Ratio: 1.5
This is certainly a wood that could get me in trouble with other instrument makers for putting as a suggestion on a list for tonewoods, but I think this would could have some interesting potential for a qin. Of all the woods listed so far, aromatic red cedar is definitely not one that is recommended by most (stringed) instrument makers. You will notice that it is by far much harder than any of the other tonewoods listed, being on the heavier and denser side as well. Also note that for its weight and hardness it has a very low elastic modulus, and is possibly the weakest of the woods in regards to strength vs weight ratio. That being said, I have actually seen it used for instruments before, on some guitars, mandolins and dulcimers, and though I have not used it myself, I plan on exploring it some time in the future. It is often said to be too brittle for a soundboard, but this is generally in reference to guitars, which require very thin woods and a wide area, supporting a lot of tension from the strings. A qin however, has a very thick and more narrow profile soundboard, so this is not that much of an issue. It also has tones of knots, which makes it difficult to work, but as a whole, knots or other imperfections may not be a complete deal breaker for an instrument. It does have a very nice grain pattern and variation in color, and would certainly make a beautiful looking (and smelling!) instrument.
Though the acoustics and dynamics are different, aromatic red cedar does in fact have its established place in the instrument world, as a very popular choice for native american flutes. I own one myself personally, and it has great tone, look, and smell, and despite being considered a rather “dead sounding” wood for guitar makers (remember that they are still very different instruments so things that work well or not for a guitar might not apply directly to a qin!), it has a very resonant response for the flute. It certainly would have a very high damping ratio compared to other woods, which could be a benefit for the qin, depending on what you are looking to get out of it – for example, it could be used to possibly dampen metallic overtones common in metal core qin strings, if you aim to make a qin for use specifically with those strings, and could result in a faster decay like silk (though these are just some educated guesses), but it would still nonetheless make a very interesting qin experiment or endeavor! In reality however, there are certainly much better and safer options, but if you are up for a challenge and really want to defy convention, this may be something to give a try.
BOTTOM BOARD WOODS
Average Dried Weight: 29 lbs/ft3 (460 kg/m3)
Specific Gravity (Basic, 12% MC): .38, .46
Janka Hardness: 550 lbf (2,450 N)
Modulus of Rupture: 9,400 lbf/in2 (64.8 MPa)
Elastic Modulus: 1,210,000 lbf/in2 (8.35 GPa)
Crushing Strength: 2,740 lbf/in2 (18.9 MPa)
Shrinkage: Radial: 2.5%, Tangential: 4.9%, Volumetric: 7.3%, T/R Ratio: 2.0
This is the traditional wood used for the bottom or back board of the qin. As you can see, one might even say that this wood could be used for a topwood as well! For a backboard, it is extremely soft and much weaker than the other woods listed below. It is not a commonly used wood in the U.S., and personally for myself, I see really no musical or aesthetic benefit to using this wood for the backboard. Particularly for natural wood finished qin with clear finishes, there are many more options that not only show off the beauty of the wood, but can very nicely compliment and customize the tone when paired with alternative top boards for a qin.
Average Dried Weight: 38 lbs/ft3 (610 kg/m3)
Specific Gravity (Basic, 12% MC): .51, .61
Janka Hardness: 1,010 lbf (4,490 N)
Modulus of Rupture: 14,600 lbf/in2 (100.7 MPa)
Elastic Modulus: 1,680,000 lbf/in2 (11.59 GPa)
Crushing Strength: 7,580 lbf/in2 (52.3 MPa)
Shrinkage: Radial: 5.5%, Tangential: 7.8%, Volumetric: 12.8%, T/R Ratio: 1.4
A very common and nice wood to work with. Black walnut can definitely be found at widths useable for qin back boards for very reasonable and afforable prices, for non-figured boards. Black walnut can be found with nice grain and figuring, however other species such as claro walnut and bastogne walnut can offer much more stunning and brilliant grain and curl, for a higher price of course. Black walnut works and finishes very nicely, and is on the softer side for backboards on this list. Acoustically it is warmer and darker than much heavier and denser woods such as bubinga and bloodwood, and would pair nicely with warm tonewoods such as cedar or redwood.
Average Dried Weight: 40 lbs/ft3 (640 kg/m3)
Specific Gravity (Basic, 12% MC): .52, .64
Janka Hardness: 1,070 lbf (4,760 N)
Modulus of Rupture: 13,190 lbf/in2 (91.0 MPa)
Elastic Modulus: 1,537,000 lbf/in2 (10.60 GPa)
Crushing Strength: 7,100 lbf/in2 (49.0 MPa)
Shrinkage: Radial: 4.2%, Tangential: 5.7%, Volumetric: 10.0%, T/R Ratio: 1.4
African mahogany is another very nice and relatively affordable wood to work with. It is lighter in color, and also warm in tone. Its mechanical properties are similar to black walnut on this list. I have used african mahogany as part of the frame for two 8 string Finnish kantele that I have made, and I quite liked working with it.
Average Dried Weight: 40 lbs/ft3 (640 kg/m3)
Specific Gravity (Basic, 12% MC): .51, .64
Janka Hardness: 1,130 lbf (5,030 N)
Modulus of Rupture: No data available*
Elastic Modulus: No data available*
Crushing Strength: No data available*
Shrinkage: Radial: 4.3%, Tangential: 6.4%, Volumetric: 10.7%, T/R Ratio: 1.5
Claro walnut can offer a stunning array of beautiful curl and figure, and is one of the most figured types of walnut, along with bastogne walnut. I have not had the chance to use this wood yet, but it is definitely on my top choice list.
BASTOGNE (PARADOX) WALNUT
Average Dried Weight: 46 lbs/ft3 (745 kg/m3)
Specific Gravity (Basic, 12% MC): .60, .74
Janka Hardness: 1,250 lbf (5,560 N)
This walnut is a rather rare species of walnut, and a very unique tree, much less known compared to the much more common walnut species such as black walnut and claro walnut. It is a combination of claro walnut and english walnut through crossbreeding and pollination. Its species is sterile, and cannot reproduce on its own. However, the tree grows larger, taller, and faster than any other types of walnut, and produces a wood much harder, heavier, and denser than any of the other walnuts. This walnut can also be found with stunning grain and curl. I used this wood for the backboard to my qin, and I couldn’t be more happy with it. I was fortunate enough to find an exceptional source of ethically harvested, beautiful fiddleback paradox walnut, with exquisite grain and figure. It pairs excellently with warm woods such as redwood and cedar. This has become one of my favorite woods out there, being not only a very unique wood, but an exceptionally beautiful wood for both tone and visual aesthetics.
Average Dried Weight: 42 lbs/ft3 (670 kg/m3)
Specific Gravity (Basic, 12% MC): .50, .67
Janka Hardness: 1,410 lbf (6,280 N)
Modulus of Rupture: 15,930 lbf/in2 (109.9 MPa)
Elastic Modulus: 1,746,000 lbf/in2 (12.04 GPa)
Crushing Strength: 8,750 lbf/in2 (60.4 MPa)
Shrinkage: Radial: 4.8%, Tangential: 7.2%, Volumetric: 12.8%, T/R Ratio: 1.5
A very popular, classic mahogany choice for instruments, this wood is common to find and readily available, and would certainly pair nicely with the above mentioned tonewoods. It falls between the walnuts and hard maple tone-wise.
Average Dried Weight: 44 lbs/ft3 (705 kg/m3)
Specific Gravity (Basic, 12% MC): .56, .71
Janka Hardness: 1,450 lbf (6,450 N)
Modulus of Rupture: 15,800 lbf/in2 (109.0 MPa)
Elastic Modulus: 1,830,000 lbf/in2 (12.62 GPa)
Crushing Strength: 7,830 lbf/in2 (54.0 MPa)
Shrinkage: Radial: 4.8%, Tangential: 9.9%, Volumetric: 14.7%, T/R Ratio: 2.1
Another very common and classic choice for a backboard wood for many stringed instruments. Hard maple is very readily available and affordable, and comes in many options ranging from plain to highly figured flame. I have used figured hard maple for several instruments before, including two 8 stringed Finnish kantele, with a mahogany frame and cypress soundboard. Tends to be on the brighter side for the more common wood choices of the walnuts, mahoganies, and maples, but not as bright and heavy as some of the more expensive and super hard exotic hardwoods that can be found. Could provide a very nice color contrast to some of the darker colored tonewoods listed above, and works, polishes, and finishes very nicely. There are some very exquisite pieces of figured maple out there just begging to be used for an amazing qin back!
Average Dried Weight: 54 lbs/ft3 (870 kg/m3)
Specific Gravity (Basic, 12% MC): .72, .87
Janka Hardness: 1,930 lbf (8,600 N)
Modulus of Rupture: 21,990 lbf/in2 (151.7 MPa)
Elastic Modulus: 2,550,000 lbf/in2 (17.59 GPa)
Crushing Strength: 11,710 lbf/in2 (80.7 MPa)
Shrinkage: Radial: 4.8%, Tangential: 8.1%, Volumetric: 12.9%, T/R Ratio: 1.7
A common substitute for the ebonies, wenge is a very hard and heavy exotic hardwood. It is a bit brittle, but offers a very bright response and looks beautiful with its black color speckled with dark brown streaks. I have used this wood before as a backboard for a 5 string Finnish kantele, with a bubinga frame and cypress soundboard, and I loved working with this wood. It has a lot of pores, so if you decide to do any French polishing with it, you will have your work cut out for you in the pore filling stage, but the wood takes a very nice polish and finish being so hard and dense. Wenge is still on the expensive side, but is still reasonably available.
Average Dried Weight: 47 lbs/ft3 (745 kg/m3)
Specific Gravity (Basic, 12% MC): .61, .75
Janka Hardness: 1,970 lbf (8,760 N)
Modulus of Rupture: 16,830 lbf/in2 (116.0 MPa)
Elastic Modulus: 1,700,000 lbf/in2 (11.72 GPa)
Crushing Strength: 8,130 lbf/in2 (56.0 MPa)
Shrinkage: Radial: 3.3%, Tangential: 5.2%, Volumetric: 7.6%, T/R Ratio: 1.6
One of my absolutely favorite woods to work with. Padauk ranges from deep red, to reddish brown, to deep, bright orange. It works and finishes beautifully, and is a very affordable and easily obtainable option. I have used it with several other instruments, and really love the color. It is hard and heavy, but works and finishes very nicely. I also have a custom made sweet potato ocarina made from a beautiful piece of exquisitely deep red padauk, with a soft, warm, and beautiful tone. A highly recommended wood for any instrument.
Average Dried Weight: 56 lbs/ft3 (890 kg/m3)
Specific Gravity (Basic, 12% MC): .72, .89
Janka Hardness: 2,410 lbf (10,720 N)
Modulus of Rupture: 24,410 lbf/in2 (168.3 MPa)
Elastic Modulus: 2,670,000 lbf/in2 (18.41 GPa)
Crushing Strength: 10,990 lbf/in2 (75.8 MPa)
Shrinkage: Radial: 6.0%, Tangential: 8.2%, Volumetric: 13.9%, T/R Ratio: 1.4
Bubinga is a lesser used wood, but one that is highly underrated. It is an absolutely beautiful wood, and extremely hard and dense, giving a very bright, woody tone. Bubinga is also personally one of my favorite woods. It’s color ranges from a beautiful orange-brown with purple veining, to some of the most exquisitely figured wood out there, aptly named waterfall bubinga. I have used this wood for a traditional 5 string kantele, and will be using it for the central part of the neck for a very unique high end Japanese tsugaru shamisen that I am designing. Both the non-figured and figured woods for bubinga are very beautiful, and I have used both to very great satisfaction. This would certainly make a very heavy and solid qin back wood, and would provide a very bright and resonant contrast for tone. I certainly plan on using this wood for many for instrument projects, and hope to use it for a qin back myself as well. It is very heavy and hard, but works very nicely with sharp tools. An absolutely beautiful and unique wood both tonally and color-wise to use, for any instrument.
EAST INDIAN ROSWOOD
Average Dried Weight: 52 lbs/ft3 (830 kg/m3)
Specific Gravity (Basic, 12% MC): .70, .83
Janka Hardness: 2,440 lbf (10,870 N)
Modulus of Rupture: 16,590 lbf/in2 (114.4 MPa)
Elastic Modulus: 1,668,000 lbf/in2 (11.50 GPa)
Crushing Strength: 8,660 lbf/in2 (59.7 MPa)
Shrinkage: Radial: 2.7%, Tangential: 5.9%, Volumetric: 8.5%, T/R Ratio: 2.2
Another great alternative for some of the more expensive rosewoods. East Indian rosewood is a hard and heavy wood with a rich, dark chocolate brown color. I have a few pieces of this wood saved up for a larger kantele that I am planning on making sometime in the future. A great wood for backboards for any instruments with a resonant tone and beautiful color. Note that though this wood is used as a common substitute for other rosewoods, it may still be listed as a potentially threatened species however.
Average Dried Weight: 66 lbs/ft3 (1,050 kg/m3)
Specific Gravity (Basic, 12% MC): .90, 1.05
Janka Hardness: 2,900 lbf (12,900 N)
Modulus of Rupture: 25,290 lbf/in2 (174.4 MPa)
Elastic Modulus: 3,013,000 lbf/in2 (20.78 GPa)
Crushing Strength: 14,310 lbf/in2 (98.7 MPa)
Shrinkage: Radial: 4.6%, Tangential: 7.0%, Volumetric: 11.7%, T/R Ratio: 1.5
Bloodwood is by far the heaviest, hardest, and densest wood on this entire list. It would make for an extremely heavy qin back, with a very loud and bright tone. Its color ranges from dull reddish brown to some extremely vibrant bright red color, though this may fade a bit over time. I have not had the chance to use bloodwood for an instrument yet, but it is certainly one of the woods on my list that I would love to use one day. Pricing for this wood is moderate, more so than the more common woods, but less than some of the more rare exotic hardwoods, and is widely available. This could certainly be used well to make a very loud and very resonant qin if paired with a very bright and resonant tonewood such as sitka spruce, and would offer great contrast in color to some of the lighter tonewoods listed above.
THOUGHTS ON WOOD CHOICES, COMBINATIONS, AND TONE DESIGN
There are so many woods out there that can be used for a qin. Certainly the traditional choices can be used, but the wide variety of woods and various combination of alternatives can open up and provide some excellent opportunities to create unique and beautiful qin. There are certainly many more woods out there than the ones that I listed above, but it may provide a good starting ground for selecting and pairing woods together. Wood properties, both mechanically and visually can be paired to compliment the tones of each wood, as well as the string selection for the instrument, and can provide a visually and sonically stunning combination if worked carefully and diligently.
In addition, just because a wood is not commonly used for instruments such as the guitar doesn’t mean that it is necessarily a bad choice for a qin or other instruments. Butternut and bald cypress are both rarely seen on instruments such as guitars, but in my own personal experience, I have used them to great success with other stringed instruments, such as the kantele. Even woods, such as aromatic red cedar, that are generally seen as poor soundboard choices by thin-topped western string instrument builders, does not necessarily mean it is inherently a bad choice for the qin. The qin in particular is a very unique instrument in regards to its construction methods, vibrational properties, soundboard thickness, and soundboard profile
In general, it is widely observed that woods such as redwoods and cedars are warmer, darker, and a bit softer in volume, while high stiffness woods, like those mainly found in the spruce family or other related woods, generally exhibit brighter and crisper tones, favoring volume a bit more a well. Each of these can be used to play to certain strengths of different string types, depending on whether you decide to go with a particular style of string for your qin. For qin, the main choice between metal-nylon strings and silk strings can almost be likened to deciding the design for either a steel stringed guitar or a classical guitar. It’s obviously not an exact analog, but is something worth considering – each style lends its strengths to different methods of play and different tonal feels. As such, choosing the woods can help impart extra flavor to the sound, or enhance certain characteristics of tone. This can be leveraged either way for both types of strings. For example, lets say you want to build a qin which will primarily use metal core strings. Metal core qin strings are inherently louder, brighter, and have longer sustain than their silk counterparts (assuming standard monofilament core and wrapping construction that is currently used for every type of m-n string out there so far, but this is a subject for another post). Using a brighter wood for the top board, such as spruce, can enhance these qualities more, if that is the tone you prefer. However, by using lower stiffness and more damped wood selections, such as western red cedar, with a back that favors stronger mid and low tones, such as walnut, you could tone back some of the brightness inherent in the metal core strings, and possibly get a bit more warmth with still good volume.
Sometimes, unexpected results may arise from wood selection and design. For example, on my personal qin, which uses curly oldgrowth redwood for the soundboard, fiddleback paradox walnut for the backboard, and gabon ebony for the bridge and nut, harmonic analysis reveals that there is an interesting additional peak that emerges in the 1khz range which is not normally observed for traditional qin. This peak exists across string type regardless of metal core or silk construction, so it is a fundamental tonal property of my qin. As a result, metal core strings sound a bit extra harsh with the metallic tone on my qin, though my intent was to use silk strings anyway. This peak however is not a bad thing, and as a whole, the qin has its own unique voice and sound profile that is measurably different from traditional qin. I did however, achieve my other design goals, in creating a qin with a warm and mellow voice, in addition to increasing volume for use with silk strings while not sounding empty or hollow. This however goes to show that wood and design choices are only at best well educated guesses, as not everything can be designed and accounted for, but the bulk tone of the instrument can still be reasonably predicted.
When choosing woods to use, take your time, plan out well, and do your research. Take your top choices and compare all of there properties side by side with something like excel. Search the internet for other instruments and makers that have used the woods and combinations you are looking at, and compare their experiences with the woods. And try to know what sound you prefer, and aim for that tone. Do you like warm and mellow sounding, or brighter with more punch? Do you want strong fundamentals and more bass, or more complex upper range? More open and resonant, or a bit more closed and introverted? Loud and bold, or soft and thoughtful? Are you planning on using silk strings or metal nylon strings? Do you want to enhance the inherent strengths of the strings, or use the wood to modify the tone into something a bit more unique? By using alternative woods, you open up a whole new world of potential tonal qualities and customization, and can free yourself from common limitations of convention. Don’t be afraid to explore new ideas or approaches!