Item# PSI-AVAA-B
The PSI Audio AVAA C20 is designed to absorb the standing modes between 15 and 150 Hz in a room. Above these frequencies, passive systems are effective. For best results, the AVAA should be installed in a room where medium and high frequencies have already been treated with passive systems. With frequencies below 150 Hz, each operating AVAA will have the same effect as a hole in the wall much larger than the dimensions of the AVAA.
The exact ratio will depend on the frequency and environment...