Assessment of sound quality: Australian native hardwood species for guitar fretboard production

Abstract

Rosewood species are used around the world in musical instrument component manufacture, most commonly for the use as the guitar fretboard. Due to the overuse of these species, rosewood has been declared an endangered wood necessitating alternatives to be sourced with similar desirable characteristics. Dynamic testing was performed on Australian high-density hardwood species with a density range of 480–943 kg/m3; the results were used for comparison with commercial Indian rosewood (IRW), used in guitar manufacturing for fretboard production. The anatomical features of the tested species were determined using microscopic imaging while dynamic testing was conducted using non-destructive, acoustic analysis. The anatomical features determined showed that certain Australian hardwood species have a strong correlation with the commercial species used for wooden instrument manufacture including frame board and soundboard production. The majority of species tested had solitary or multiple vessel type, vasicentric parenchyma and uniform ray types. The internal friction versus the specific dynamic modulus for the species tested were in a similar range of the IRW samples. The quality factor versus temporal damping of species tested showed potential similarities between the species IRW, with red siris (RSI), and red tea tree (RTT). From the study conducted, four species including: RTT, RSI, Queensland walnut (QLW) and Calophyllum (PTG) have been selected for further testing and fretboard prototyping; the selected species will be tested for quality of sound and strength in the manufactured prototypes.