AVS Forum Club Gold
Join Date: Jul 1999
Location: Near an airport
Mentioned: 8 Post(s)
Tagged: 0 Thread(s)
Quoted: 64 Post(s)
Ethan is not entirely correct, nor is he entirely incorrect either. There are two purposes for the use of absorption in a playback space. One is to solve direct acoustical issues. For example, SBIR when speakers are near a boundary, back reflections from an AT screen, or, in some cases, to knock down the effect of early reflections (usually diffusion is more useful). In this case, the placement of the absorptive treatments becomes part and parcel of their performance.
The second reason is to reduce the overall reverberation time in the room. In this case, the position of the absorptive material is less important than its very presence in the room. For this purpose, ear height and below would work.
In actual practice, you may absolutely want absorptive materials to stay out of early reflection points. An example would be the use of diffusors to expand sound stage width, depth or to enhance the surround channels. At the same time, absorption needs to be placed in the room to reduce reverberation time. This would be a real case where absorptive panels in less than obvious locations is required.
Dennis Erskine CFI, CFII, MEI
Subject Matter Expert
Certified Home Theater Designer