When a sound wave meets a surface, a part of the energy is reflected, the rest is absorbed by the material of which this surface is made and depends on the nature of the material, its mass, surface area and frequency.
A material that absorbs 45 percent of energy at a given frequency has an absorption coefficient of 0.45 for that frequency. Absorption is measured in Sabines (coefficient x unit area).
By knowing the surface, the absorption coefficient of the materials and the volume of a listening room, we can calculate the reverberation time (RT60) for each frequency.
Double click on the 4 walls, roof and floor to select materials. Other surfaces are optionnal but help for a best rendering