Using this subwoofer is easy. First, find a suitable location for it in your room, preferably on a flat and stable surface. Connect it to your audio system according to the instructions. When it comes to volume, start at a low level and gradually increase it to your desired sound. Be careful not to place it in a very humid or dusty environment as it may affect its performance. For maintenance, clean the exterior with a soft, dry cloth regularly. If you notice any other issues besides the missing grille foam, it's best to contact a professional for help.