Chemical treatment of wood for musical instruments. Part I: acoustically important properties of wood for the Ranad (Thai traditional xylophone)

The purpose of this study is to determine the important acoustic properties of wood for making Ranad bars and the resonator box. The woods used in this study were separated into two groups. The first group is the type of wood that has been used to make Ranad for centuries: Ching-Chan (Dalbergia oliveri Gamble) and Ma-Had ( Artocarpus lakoocha Roxb.) for making the bars, and Ka-Nun ( Artocarpus neterophylla Lamk.) out of which the resonator box is made. The second group comprises woods that are abundant in Thailand and are genetically related to the first group. The physical and mechanical properties of the woods in both groups were measured including the specific dynamic Young's modulus (E/rho), density (rho), hardness ( H), acoustic conversion efficiency ( ACE), and sound refraction coefficients (|Gamma|). The results revealed that high and consistent |Gamma| were crucial factors of the Ranad bar properties in addition to E/rho, rho, and H. The results from measurements made on the resonator box wood revealed that high E/rho, ACE, and high and consistent |Gamma| were its crucial properties.