Quote:
Originally Posted by Weasel9992  the excel spreadsheet you provided expressed the difference in terms of decibels. |
Yes, assuming a rigid massive backing so whatever is not absorbed is reflected. Which is how the underlying data was measured.
Quote:
|
Again I ask how you get around the fact that there is a .14 dB difference between wood and concrete, and that when that is extrapolated to 1440sqft it amounts to a 3dB net difference?
|
You can't extrapolate because the data itself is dimensionless. That's my whole point. Absorption coefficients are dimensionless, and so are reflection coefficients. And, by extension, the reflection dB equivalents.
Quote:
|
you also didn't explain how you would extrapolate the test results to a larger scale
|
I honesty don't know how else to say this. There is nothing to extrapolate. The idea that you can scale the dB numbers, or would need or want to scale them, is fundamentally flawed. In the same way it is flawed to try to convert absorption coefficients from being dimensionless to having a dimension. Once you understand why you can't extrapolate absorption coefficients, you'll understand why you can't extrapolate reflection coefficients either. This is exactly why coefficients are used in the first place!
--Ethan