Acoustic Loss Factor- a measure of the ability to reduce structural
borne sound. It represents how much vibration related energy is absorbed by the
material at a given temperature. Based on a linear scale of 0 - 1, with 0 being an undamped steel panel
and 1 being a theoretically perfectly damped panel (no vibration). The higher
the ALF, the more effective the material is. Also known as Damping Loss Factor (DLF)
Transmission Loss - the reduction in noise level resulting from
passage through an obstruction at a given frequency. Sound transmission class (STC) is the
overall measurement of
the effectiveness of a material to attenuate sound. Values are expressed in
decibels and as such form a logarithmic scale. The higher the transmission loss,
the more effective the material is.
Absorption Coefficients
- the amount of sound energy a surface absorbs and reflects at a given frequency. If we say that a surface material has an absorption
coefficient of 0.25 we are saying that the surface will absorb 25% of the
incident acoustic energy, while reflecting back 75% of the total acoustic energy
at the specified frequency. The higher the absorption coefficient, the more effective the material is.
Dynamat® is a registered trademark of Dynamic Control of Dayton, OH.
B-Quiet® is a registered trademark of
StereoTypes of Lethbridge, AB, Canada.
