Type “A” vs. “E” Installation Method
Type “A” mounting involves mounting the Acoustifoam directly to the surface (ie: with no gaps, and no additional material laminated into the assembly). The Décor panel will then intake incident sound waves, which will break down as they pass through the foam until the hit the hard surface, bounce off of it, and whatever sound is left will escape in a lessened form. In the sketch below, the RED line signifies noise entering the material, with the BLUE line being the force that is transferred into the testing surface when the noise reaches it, and then the thin red line being the sound leaving the material (assuming the NRC is below 1.0).
Type “E” mounting involves leaving a gap between the acoustic material and the hard surface or substrate. The noise enters the acoustic material (RED line), breaks down going through the material (YELLOW line, and then exists and decays (GREEN lines). The BLUE line shows the impact force going into the substrate), and the Purple Line shows the sound re-entering the acoustic material before it finally exits.
The Type “E” method will always result in an higher NRC value (when compared to Type “A”), due to the fact that there is an extra stage of decay between the impact and the absorption when the noise passes through the foam on its way back to the source of the noise.
