SPEAKERCRAFT AcoustaCell 8 Wall Damping System When Installed behind the Speaker, it forms a Precision Sonic Chamber The Entire AcoustaCell 8 System installs thorugh the standard Speaker Wall Opening Allows the Woofer to Produce Deep Bass Frequencies Virtually Eliminates Helmholtz Resonance and Standing Waves Subdues Out-of-Phase Drywall Resonance, Allowing Extended and "Tighter" Bass to Reach the Listener