I am trying to predict the reverberation time in a room with different surfaces and different absorption coefficients (i.e. curtains, wood panels, carpet etc). My question is about how to calculate the overall absorption coefficient and area of absorption if you have two different layers of material? For example:
If there is a curtain with an absorption coefficient of 0.5 @ 500Hz, hanging in front of a wall with an absorption coefficient of 0.2 @ 500Hz, how do i find the overall absorption coefficient and area of absorption?
Thanks for your help, Jaryd