AudioCircle
Audio/Video Gear and Systems => The Acoustics Circle => Topic started by: bernardo on 14 Jul 2022, 01:07 am
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I am reviewing various acoustic treatment products. Manufacturers rate their bass traps as Sabins versus frequency or Absorption Coefficient versus frequency. Is there a conversion that can be used between Sabins and Absorption Coefficient so that I can compare apples to apples?
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https://www.acousticfields.com/sabins-and-sound-absorption-coefficients/ (https://www.acousticfields.com/sabins-and-sound-absorption-coefficients/)
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In addition to absorption, you should also consider:
- Diffusion
- Room modes
- First order reflections
- Reverberation times
- Flutter echo
https://avroomservice.com/ (https://avroomservice.com/)
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NWAA's Ron Sauro on Shape and Absorption - a mini treatise on absorption
https://www.stereophile.com/content/nwaa-labs-measurement-beyond-atomic-level-shape-and-absorption (https://www.stereophile.com/content/nwaa-labs-measurement-beyond-atomic-level-shape-and-absorption)
"Absorption is the most common treatment used in listening rooms. The measurement of absorption was first described by Wallace Sabine, who compared the reverberation times of a room with and without absorption. This difference was then converted to units of absorption using this formula:
A = 0.9210(V*d/c)
where
A = equivalent absorption area in m2,
V = volume of reverberation room in m,
c = speed of sound at ambient temperature and humidity in m/s,
and d = decay rate in dB/s.
"Most of what we think we know about absorption is wrong! Absorption calculations in use today can err by as much as 85%. The biggest error concerns how important the area of absorption is in the calculation of how much absorption is needed."