Speed of Sound in Grain Direction
As moisture content rises, propagation speed generally decreases.
Trend: moisture increase -> lower sound velocity
Moisture-Driven Changes in Tonewood Behavior
Research visuals used in de/Humi materials to explain velocity, damping and stiffness behavior under changing moisture.
Internal Damping (tan delta)
Damping tends to rise with moisture, reducing transient sharpness.
Trend: moisture increase -> higher damping
Dynamic Stiffness / Elastic Modulus
Higher moisture usually lowers stiffness and shifts response.
Trend: moisture increase -> lower stiffness
Technology & Science
Material science behind humidity, wood moisture and tonal behavior.
Technology & Science
de/Humi is engineered for practical luthier conditions where dimensional stability and predictable acoustic response matter.
Why humidity matters
Wood is hygroscopic. As moisture changes, key physical and acoustic parameters also change:
- Mass changes with water uptake.
- Dynamic modulus and stiffness shift with moisture level.
- Internal damping often rises with higher moisture content.
These effects can influence attack clarity, transient response, sustain and projection.
Why controlled mid-range RH matters
Many workshops build and service instruments around mid-40s RH for dimensional neutrality. de/Humi is tuned for that practical working zone while operating in a safe range.
Operating target
- Functional band: 40-55% RH
- Practical target: 45% RH
Public references
- Bucur, V. Acoustics of Wood (Springer)
- Bremaud et al. (2011), Wood Science and Technology
- USDA Wood Handbook
- MDPI Materials review on moisture and wood behavior
- Effect of moisture content on the ultrasonic acoustic properties of wood (Springer, 2015)