Influence of geometric parameters on the acoustic characteristics of a Chinese xun based on parametric modeling and finite-element analysis

Traditional xun design relies largely on empirical adjustment, and the relationship between geometric parameters and acoustic responses remains insufficiently quantified. This study investigates the effects of blowing-hole diameter, cavity-wall thickness, and cavity convergence coefficient using parametric modeling and finite-element acoustic analysis. Results show distinct, parameter-specific effects. Blowing-hole diameter primarily affects pitch, producing a fundamental-frequency variation of about 93 Hz. Cavity-wall thickness more strongly influences timbre-related metrics, with the spectral centroid and high-frequency energy ratio reaching 2811 Hz and 0.777, respectively. The cavity convergence coefficient affects both pitch and high-frequency modal responses. The spectral centroid and high-frequency energy ratio are strongly correlated (r = 0.92), whereas the fundamental frequency is weakly correlated with timbre-related metrics. Experimental validation yields a mean relative deviation of 1.18%. These findings provide quantitative support for digital acoustic analysis and geometric design of traditional wind instruments.