Does a dulcimer get a fuller tone when broken in?
General mountain dulcimer or music discussions
Yes, regular playing and aging of wood in music instruments does help create a more resonant tone, and it’s not the strings. Humidity and “creep” (a glue’s tendency to pull apart slowly when it is put under a continuous load) are believed to be mostly responsible. It is known that playing regularly in high humidity environments leads to a decrease in loss coefficient (the degree to which the wood dissipates vibrational energy via internal friction) and an increase in stiffness (Hunt and Balsan 1996). Evidence by Beavitt (1996) shows that creep facilitated by humidity cycling changes the overtone spectrum of an instrument, making it more resonant and more sonorous. Creep in newly strung instruments is accelerated by vibration absorption in the wood which is why you can help a new instrument settle in faster by playing it or exposing it (via those “blaring speakers” Ken mentions, for example) to those vibrations (Segerman 1996, 2001). It’s also been shown that the gradual loss of hemicellulose in wood (as it decomposes with time) lowers its density without affecting its Young’s modulus (one of the most important determinants of the acoustic properties of a material), which improves the sound radiation coefficient of the wood (another important determinant)(Bucur 2006). In fact, that understanding has led to some very interesting research in aging soundboards by deliberately infecting the wood with fungus to lower its density while keeping the Young’s modulus constant, again improving the sound radiation coefficient (Zierl 2005, Schwarze 2012).
Strings also have an effect on tone, depending on their material, age, etc. but they are not responsible for the sweeter sound of aged instruments, except insofar as if you are like me, and much prefer the warmer "deader" sound of old strings that have built up a layer of crud on them (from shed skin cells, oils etc) compared to the brighter sound of brand new strings. (And yes, I realize I'm in a very small minority here with that preference).
Hope that helps a little.
HUNT, D. G., AND E. BALSAN. 1996. Why old fiddles sound sweeter. Nature 379: 681.
BEAVITT, A. 1996. Humidity cycling. Strad (Nov): 916–920
SEGERMAN, E. 1996. Wood structure and what happened in the Hunt & Balsan experiment. Fellowship of Makers and Researchers of Historical Instruments Quaterly 84, Communication 1471: 53–55.
SEGERMAN, E. 2001. Some aspects of wood structure and function. Journal of the Catgut Acoustical Society 4: 5–9.
BUCUR, V. 2006. Acoustics of wood, 2nd ed. Springer Series in Wood Science, Springer, Berlin, Heidelberg, Germany.
ZIERL, B. 2005. Obtaining the perfect violin sound - with fungi. Website https://www.empa.ch/web/s604/01-pilzholz [Accessed 06 May 2016].
Max Delbrück Center for Molecular Medicine. "Treatment with fungi makes a modern violin sound like a Stradivarius." ScienceDaily. ScienceDaily, 8 September 2012. <www.sciencedaily.com/releases/2012/09/120908081611.htm>.
updated by @Brian G.: 05/06/16 07:25:56PM