◆ The Soul of CAMAC Harps—The Soundboard ◆
About the Soundboard
(Photos, original text/ CAMAC HARPS. Translation/ Emilie Kuo)
The "soundboard" can be considered the soul of every harp.
We all know that the sound of the harp comes from the vibrations produced when the strings are plucked. The function of the soundboard is to receive these vibrations and transform them into the music we hear. It not only amplifies the sound but also determines its quality. Therefore, one of the greatest hopes of harpists is to have a high-quality soundboard as part of their harp. This is because installing a brand new soundboard effectively gives the harp a different, new sound.
When it comes to making the soundboard of a harp, no other wood is more suitable than spruce (Note 1), especially the entire "resonance board" that mainly captures the vibration of the strings. If other woods are used, they will need to reach a certain thickness under a certain tension, but such thickness will also reduce the sensitivity of capturing the vibration of the strings. The stiffness-to-weight ratio of spruce is better than that of other woods. If spruce is used to make the soundboard, it does not need to be as thick as other woods, but it can withstand the same tension. Therefore, relatively speaking, spruce can maintain the highest sensitivity in capturing the vibration of the strings.
For example, the thickness of the speaker board of our CAMAC harp speaker ranges from 10 mm (1 cm) at the bottom bass to 2 mm at the top. This piece of wood needs to withstand the tension of up to two tons of all the strings! Therefore, considering that the thickness must be at least 1 mm, we can imagine how strong "spruce wood" is.
CAMAC HARPS has chosen to cooperate with a "spruce wood" supply partner, the Holzwerk Strunz family from Germany, living in the Alps. The Holzwerk Strunz family's timber business began in 1820 and is now managed and operated by Thomas Hilz. The forests selected by this family are all so-called "sustainable" and PEFC (Note 2) certified forests, which means that the trees they plant and cultivate must be more than the trees they cut down, and there is a necessary standard ratio. Only in this way can they maintain a stable balance in the entire nature under the environmental protection concept of using wood and sustainable forest environment.
The Holzwerk Strunz family is very strict in selecting "spruce wood". Here they only use "spruce wood" that grows almost perfectly. The reason is that the growth process of trees is related to the uniformity of the annual rings, and uneven annual rings will have a negative impact on the tone of the instrument. Therefore, their quality control and production procedures must undergo very careful inspections and quality controls before the products leave the production line. Here, we would like to thank our partner, the Holzwerk Strunz family, again. Their 200 years of accumulated requirements and persistence for "spruce wood" allow us to fully guarantee the quality of CAMAC harp wood.
(Photo) Jakez confirms a new batch of spruce logs to be delivered in the sawmill
(Photo) The Alps, where the selected spruce trees grow in this beautiful region. It is said that the view from the back of the Alps is known as the "Bishop’s Hat,"
because the combination of the landscape and the snow resembles a bishop's hat. This area is believed to possess special frequencies and energy.
In the Alps, the "harvesting" of mature spruce trees can only take place in winter, typically from October to March of the following year. During this time, young spruce trees are also planted according to the regulations of the PEFC "Sustainable Development Program." The forests selected by the Holzwerk Strunz family, particularly in Austria, are well-managed. They first ensure that the young spruce trees have established strong roots and are growing well before selecting which trees to harvest. As a result, their forests rarely appear bare.
When the chosen spruce trees are cut down, they are sent directly to the sawmill. This process often requires great patience, as heavy snowfall can make mountain roads impassable. If that happens, the logs must remain on the mountain until the roads are cleared for transport. Once they reach the sawmill, the processing can begin! These spruce logs must be handled as quickly as possible; if left at room temperature or in warmer conditions for too long, the wood can develop black spots. While this won’t affect their strength-to-weight ratio, it will impact the appearance of the finished instruments.
The ideal spruce for making soundboards requires very dense grain (sometimes so tight that the wood grain is nearly imperceptible to the naked eye), measuring approximately 12-15 cm from the center of the log inward. Thomas Hilz explains, “The center of the log is not suitable for making soundboards because it comes from the tree's younger years, which have many knots. Although the tree will gradually mature and widen, these knots will remain in the center.” Additionally, from 100 logs, nearly two cubic meters of high-quality soundboard wood can be produced. The remaining wood is used for construction, furniture, and window and door manufacturing.
Each "spruce" log will first be cut at least twice, and then enter the first stage, which is to be stored in a professional drying kiln for a long time according to different thicknesses. This is because the wood used to make speaker panels must be very dry. If it is not dried to a certain degree, the wood will slowly shrink over time, which will cause the speaker panels to deform or even crack.
Thomas Hilz, the person in charge, said: "Normal spruce logs contain about 50% moisture after felling. When placed in an environment at normal sea level, the moisture content will be about 20% after about six months. Then we will put the logs into a professional drying kiln to reduce the moisture content of the spruce logs to about 6%." "After the moisture content of the spruce logs is reduced to 6%, they will be transported to a drying room controlled by computer instruments. After a drying process of nearly 2 to 4 weeks, because the logs will absorb some moisture during the transportation process, the moisture content of the logs can be further reduced in this drying room controlled by computer instruments."
The entire process of drying spruce logs puts significant stress on the wood. However, if the moisture content can be successfully reduced to 6%, the likelihood of cracking during subsequent drying processes will be minimized. For this reason, the spruce logs selected by CAMAC, whether at the Strunz factory in Germany or our studio in Mouzeil, France, undergo a resting period of at least three months. During this time, they are kept in an environment with an average humidity of 7%. This resting period is a crucial stage for the stability of the wood.
The entire process of drying spruce logs is very stressful for the logs, but as long as the moisture content of the logs can be successfully reduced to 6%, the probability of cracking in the logs will be minimized during the subsequent drying process. For the same reason, the spruce logs selected by CAMAC, whether in the factory in Strunz, Germany or our studio in Mouzeil, France, will experience a static period of at least three months, placed in a room with an average humidity of 7%. This static period is a very important test stage for the stability of the logs.
Before the spruce logs are shipped to the CAMAC studio in Mouzeil, and after going through all the drying and resting processes at the Strunz factory in Germany, they enter the final stage before leaving the factory, which is the third cutting. At this time, the craftsmen will make a final confirmation of the logs and cut off as many remaining defects or limitations as possible. In addition, each craftsman will make a small mark on the logs that have been handled without affecting the quality and appearance of the logs. This is to allow us to have a more reliable and direct basis for controlling the quality of the logs used to make the harp.
(Photo) Discussing the final cut, (left to right) Thomas Hilz, Viktor Geier, Jakez
After the spruce wood has gone through all the log processing procedures in Germany, it will be sent to CAMAC's studio in Mouzeil and will enter the drying and stabilization process arranged by us until the condition and moisture content of all the spruce logs are confirmed to be completely stable. Then it will directly enter the production stage of the "harp soundboard".
First, we will select the "spruce" wood to be used as the speaker board, make it into many thin slices, and then stack them vertically and horizontally to form the prototype of the speaker board, and grind the side that will face outward so that the surface veneer can fit it smoothly; the next step is an extremely precise and delicate step, because cutting into a cone-shaped shape like a speaker board must be very accurately symmetrical. After the cutting is completed, you can add the central hardwood strip with the string holes drilled in it. In addition, we will add a strong supporting center column inside the speaker and several supporting wooden strips close to the outer layer of the speaker to strengthen the entire speaker structure, because a stable speaker structure is very important for sound quality and clarity, and of course it also has a great impact on the life of a harp.
The last and most critical step is to determine the position of all the strings, which is to accurately combine the speaker and the speaker board. Then we enter the final stringing stage of the harp production, and the entire production is almost completed.
(Photo) One day, all these spruce trees behind Jakez may become CAMAC harps.
When we understand the entire process of making the harp,
we will realize that what we see is not just a CAMAC harp,
but a beautiful instrument infused with two hundred years of soul!
<Note 1> Spruce: A genus of evergreen tree belonging to the Pinaceae family. This genus has 35 species distributed in the northern temperate zone. In 2008, researchers announced the discovery of a 9,550-year-old Norway spruce on Mount Folkestone in Sweden, making it the oldest living plant in the world.
＜Note 2＞PEFC: A forest certification promotion group established with the support of various industry groups representing the forest industry. In June 1999, representatives of forest management groups from 11 European countries gathered in Paris to establish the "Forest Certification and Endorsement Program Committee (PEFC Council)" certification system, which is a forest certification system that can better reflect the interests of forest operators. It is an independent, non-profit, non-governmental organization. Its purpose is to promote the mutual recognition of third-party certification systems to promote the sustainable management of forests. As of March 2012, PEFC has passed the PEFC certification program certification for a total area of 243.19 million hectares in 29 countries. (PEFC official website: http://www.pefc.org/ )
Editor's note: This article is translated from "The story of our soundboards" on CAMAC HARP BLOG (click on the article title to see it). If you are interested in the original article, you can go and take a look at it for more detailed information!