Subwoofers are electro-mechanical devices. The voice coil assembly has electrical winding, and it mechanically moves the diaphragm and the damping mechanism of spider. Binding adhesive is an integral part of subwoofer construction. The diaphragm, spider and the metallic chassis are joined together with special purpose adhesive glue. 7 to 8 hours of break-in period for your subwoofer is recommended to loosen up and even out the stressed areas, fresh out of manufacturing.