The choice of wood for a guitar is not only a question of appearance, but also one of acoustics. For a long time, tropical wood, in particular the precious Rio rosewood or later Indian rosewood, for reasons of species protection, was regarded as the ultimate in guitar making. These wood species convince with their special tone.
Classical guitars were often made from a combination of long-stored tropical wood species such as West Indian cedar for the neck, East Indian rosewood for the body and back and ebony for the fingerboard. Since the beginning of 2017, however, the trade with endangered tropical woods has been subject to stricter regulations. This is why musical instrument makers have to turn to alternatives. But how can the excellent tonal and optical properties of tropical woods be achieved?
Engineers from TU Dresden in cooperation with the Franconian guitar manufacturer Hanika are now working on this. For their research work, they subjected native woods such as spruce, maple and cherry to a specially developed thermal treatment. And in the meantime, this has become so sophisticated that the research team is convinced that it can offer at least the same acoustic properties as tropical wood. This was demonstrated, among other things, in an acoustic test of the thermally treated wood (see lead picture). The vibration properties are decisive for the sound quality. In addition, there was a plucking test of the guitar (see picture below), which examines how long it takes for a tone to be audible and how long the tone remains audible.
We have managed to ensure that European woods now also have excellent sound properties and are a real alternative to tropical wood”, says Dr. Mario Zauer, scientific assistant at the Chair of Wood Technology and Fiber Materials Technology at TU Dresden.
The TU Dresden treatment process is used to thermally treat native woods at a certain temperature and pressure for a certain period of time. This accelerates the necessary ageing processes of the wood. The thermally modified native woods can then be processed into high-quality musical instruments after only one year. The Dresden wood technicians are thus in a position to provide a regional substitute material for species-protected tropical wood. Another advantage of the processed wood is its rapid availability: the tropical woods used so far have to be stored and air-dried for about six to ten years before they can be used as so-called tonewoods for the construction of instruments.
Handicraft Project of the Year
Meanwhile Hanika produces four new, completely tropical wood-free guitar models (basic, middle, upper and master class) from local woods.
Zauer, who is also project manager of “Konzertgitarre” (Concert guitar), comments:
For me as a scientist, it’s nice to see that our wood treatment process is implemented by Hanika in its own guitar series. This shows that our research work of several years has really paid off.”
The TU Dresden and Hanika are partners in a cooperation network within the framework of the Central Innovation Program for Medium-Sized Businesses (ZIM). This alliance brings great success: The TU Dresden received 175,000 euros in funding from the BMWi for the ” Konzertgitarre” (Concert guitar) project between 2015 and 2017. And the guitar manufactory was awarded the “ZIM Handicraft Project of the Year” on 9 May 2019 at the Innovation Day for Medium-Sized Businesses of the Federal Ministry of Economics and Energy (BMWi) in Berlin.