Structural acoustics model of the violin radiativity profile

Area of Science:

• Acoustics
• Musical Instrument Physics
• Vibrational Analysis

Background:

• Violin sound radiation is complex, influenced by various resonant modes.
• Key modes include the Helmholtz-like A0 cavity mode and corpus bending modes (B1-, B1+).
• Previous research suggests coupling between modes affects sound output.

Purpose of the Study:

• To investigate the relationship between specific violin modes and their contribution to radiativity.
• To model the vibration-to-acoustic energy transfer and identify factors influencing spectral balance.
• To validate empirical links between B1 modes and perceived sound quality.

Main Methods:

• Analysis of VIOCADEAS data to correlate mode frequencies and radiativity.
• Estimation of the critical frequency (f(crit)) for vibration-acoustic energy filtering.
• Computational modeling incorporating string-corpus interactions and mode couplings.

Main Results:

• A0 radiativity increases as the frequency difference between A0 and B1(-) modes decreases.
• The vibration-acoustic energy filter (F(RAD)) peaks at the critical frequency (f(crit)).
• Increased plate thickness lowers f(crit), reduces F(RAD), and shifts spectral balance to lower frequencies.

Conclusions:

• The A0 mode is excited via coupling with B1 modes, influencing f-hole volume flow.
• f(crit), derived from a free-plate mode, is crucial for spectral balance and radiativity.
• The developed model, including mode couplings, substantiates the link between B1 modes and violin sound quality.