absorption coefficient is to 1.00 , the greater the absorption . Notice , on the previous chart , the difference in absorption between lower and higher frequencies . Many soft surfaces , which one might guess would be absorptive ( carpet , acoustical tile , and so on ) exhibit little to no absorption at 125 Hz .
DIFFUSERS It ’ s often most desirable to control interfering reflections using diffusion instead of absorption . A diffuser confuses and randomizes reflections rather than absorbing them . This tool provides control without robbing the room of its ambient life .
There are several designs used to construct diffusers . Some are constructed of wood , and some use synthetic materials ; however , the purpose is the same , regardless of the physical characteristics . Diffusion panels are placed at any position in the acoustic space that requires reflection control .
THE CEILING Ceiling design is a critical factor in acoustic design . Standing waves between the ceiling and floor provide ample opportunity for tonal coloration and destructive sonic interaction . Many large rooms include a high ceiling that slopes up to a point . Although this helps focus the sound back down to the audience , it might be 20 to 50 feet high , which delays the sound coming back to the audience by between 40 and 100 milliseconds . Delays of this length can easily form flutter echoes and delays that confuse sonic integrity and intelligibility .
CLOUDS Typically , angled panels suspended from the ceiling above the audience are used to diffuse and deflect the focused and standing waves .
These panels , called clouds , help shape the feel of the acoustic space . They can transform a large and cumbersome acoustical space into a room with a much tighter and more intimate feel .
Ceilings that rise to a center-point focus reflections right back into the middle of the room . If the ceiling is flat , it contributes dramatically to any standing wave problems . A common ceiling treatment involves flying a series of clouds across the length of the audience . Clouds are typically nothing more than a series of angled panels that deflect standing waves and reflect sound evenly down to the audience . Depending on the height and angle of the clouds , it is possible to tame the wildest of venues . Clouds also let the audience hear their own interactions with , and reactions to , the performance .
Stage
Clouds ( hanging panels ) are efficient diffusers , but they also help shape the intimacy of the experience for the audience .