Acoustic Properties of Syzygium sp., Dialium sp., Gymnostoma sp., and Sindora sp. Wood

Acoustic properties such as specific dynamic Young’s modulus (Ed/γ), internal friction (Q), and acoustic conversion efficiency (ACE) of wood are important properties frequently examined using free-free flexural vibration. This study determined the suitability for making musical instrument soundboards and frameboards from four tropical wood species; namely Syzygium, Dialium, Gymnostoma, and Sindora. The results show that (Ed/γ), (Q), and ACE were in the range of 20.0 to 28.9 GPa, 0.0031 to 0.0085, and 3.41×10 to 10.83×10, respectively. Based on the results, Syzygium was preferred for making the frameboard of violins and guitars. The outer sapwood (outer part) of Syzygium was the most suitable for making frameboard by considering the lowest ACE and highest Q. Based on Ed/γ, the inner sapwood (middle part) in Dialium was the most suitable for making soundboard, but based on Q and ACE, heartwood (inner part) was the most preferred for making soundboard. Gymnostoma was also preferred for making soundboard of violins and guitars (inner sapwood) because it yields the highest mean value of Q and ACE. Considering ACE and Q, the outer sapwood in Sindora was the best for making frameboard. When considering Ed/γ and Q, the heartwood is the most suitable for making the frameboard of violins and guitars.