Model-predicted geometry variations to compensate material variability in the design of classical guitars

Area of Science:

• Acoustics
• Musical Instrument Science
• Materials Science

Background:

• Musical instrument making is traditionally an art form with elusive scientific principles.
• Historical instruments like Stradivari violins and Torres guitars are considered benchmarks.
• Variability in wood materials presents a significant challenge in replicating acoustic properties.

Purpose of the Study:

• To develop and validate a method for matching the vibrational response of guitar top plates with differing materials.
• To demonstrate the feasibility of creating accurate acoustic copies of instruments.
• To bridge the gap between artistic craftsmanship and scientific quantification in instrument making.

Main Methods:

• Utilized state-of-the-art methodologies for vibrational response analysis.
• Constructed two guitar soundboards: a reference and a copy.
• Applied model-predicted geometry variations to the copy soundboard to match the reference.

Main Results:

• Experimentally validated the predictive accuracy of the numerical model for geometry changes.
• Significantly reduced vibrational response deviations between the two guitar top plates.
• Demonstrated a method to achieve acoustic similarity despite material variations.

Conclusions:

• The developed methodology enables precise acoustic matching of instrument components.
• This approach can be extended to other instruments like violins.
• Instrument making can transition towards a more scientific discipline, facilitating the replication of valuable historical instruments.