TONEWOOD ARCHIVE · WOODPEDIA

Woodpedia

From a piece of wood to the science of sound.

Understand a concept through a knowledge entry, or follow a complete question through a feature article. Start with everyday analogies, illustrations and interactive experiments to explore materials, vibration, sound and the limits of measurement.

Feature articles

1 article

Connect concepts, methods and practical applications through a complete reading journey.

Luthier Franz Übelhör uses a small finger plane to carve the inside of a violin back plate

✦ In-depth Feature Guide

Wood Acoustics: From Experience to Data

A continuous reading journey from violin-making experience to material properties, acoustic measurement, evaluation and traceable records, with equations and interactive examples.

~15 min reading•6 interactive acoustic figures

Read full article

Kritzolina · Wikimedia Commons · CC BY-SA 4.0

Knowledge entries

25 / 25 entries

Explore one concept at a time, from intuition to equations and interactive experiments. No physics background required.

Vibration · Beam modes Interactive

Beam boundaries, bending modes and βₙ

How do end constraints change the way a beam bends?

Elasticity · One dimension Interactive

Springs and Hooke’s law

Why do two springs stretch by different amounts under the same force?

Close-up of a Norway spruce cross section showing curved growth-ring bands

Material mechanics · Three dimensions Interactive

Wood directions and three-dimensional elasticity

Can one elastic modulus describe a piece of wood?

Rasbak · Wikimedia Commons · CC BY-SA 3.0

Acoustics · Wave propagation Interactive

Longitudinal wave speed

Over the same distance, which pulse arrives first?

A quarter-sawn sugar maple blank showing its end grain and broad face

Material fundamentals · Mass and volume Interactive

Density and the weight of a blank

Is a lighter blank necessarily made of lighter wood?

Stephen Ondich · Wikimedia Commons · CC BY-SA 3.0

A hand holds an electronic moisture meter against a wooden board

Material fundamentals · Environment Interactive

Moisture content and conditioning

Why can the same piece measure differently next week?

Hrco · Wikimedia Commons · CC BY-SA 4.0

Material fundamentals · Elasticity Interactive

Dynamic Young’s modulus

What does “stiff wood” actually describe?

Material fundamentals · Shear Interactive

Shear modulus and twisting

Why can a plate resist bending yet twist easily?

Material fundamentals · Coupling Interactive

Poisson’s ratio and coupled deformation

When wood stretches along the grain, what happens across it?

Acoustic properties · Stiffness and inertia Interactive

Specific stiffness

How much stiffness is available for the mass carried?

Acoustic properties · Light and stiff Interactive

Material radiation ratio

What does combining wave speed with density tell us?

Acoustic properties · Stress and velocity Interactive

Characteristic acoustic impedance

Does material impedance equal the impedance felt by a string?

Acoustic properties · Dissipation Interactive

Loss factor and internal friction

Where does the energy go after a tap?

Acoustic properties · Resonance Interactive

Quality factor, decay and bandwidth

Does a longer ring always mean a larger Q?

Acoustic properties · Composite indices Interactive

Acoustic conversion index ACE

What changes when radiation ratio is combined with loss?

Measurement methods · Signal analysis Interactive

Frequency spectra and FFT resolution

Does the tallest spectrum peak always identify the mode?

Colored salt forms branching nodal patterns on a vibrating metal Chladni plate

Measurement methods · What is vibrating? Interactive

Modes, nodes and peak identification

How do we know which vibration a frequency belongs to?

Carlos Andrés Reyes · Wikimedia Commons · CC BY 2.0

Measurement methods · Boundary control Interactive

Tap locations and soft supports

Can the way we hold wood change the result?

Measurement methods · Inverse models Interactive

Inferring modulus from a bending resonance

How can a tap become an elastic modulus?

A digital caliper with jaws, measuring beam and LCD readout

Measurement methods · Reliability Interactive

Uncertainty and thickness sensitivity

Why can a tiny thickness error move the modulus so much?

Lior Streng · Wikimedia Commons · CC BY-SA 4.0

Luthier Franz Übelhör uses a small finger plane to carve the inside of a violin back plate

Violin making · Material and geometry Interactive

Thickness, arching and modal frequency

Why does thinning change both mass and stiffness?

Kritzolina · Wikimedia Commons · CC BY-SA 4.0

Close-up of violin strings crossing a wooden bridge whose feet meet the top plate

Violin making · The sound chain

From bridge motion to radiated sound

Where does a material measurement stop explaining the violin?

Adam Shaylor · Wikimedia Commons · CC BY-SA 2.0

Reading the data · Project rules Interactive

ToneWood Acoustic Score

What does a score of 100 actually mean?

Reading the data · Relative position Interactive

Percentiles, ties and reference groups

Can a material’s percentile change without its measurements changing?

Reading the data · Reproducibility

Traceable records and a useful database

What makes one measurement useful years later?