The Acoustimass module from sound system manufacturer Bose is the subwoofer portion of a system with satellite speakers. It connects to a receiver and produces the low-end frequencies that can be felt as well as heard. The Acoustimass subwoofer is a large, polymer box that is placed on the floor adjacent to the television set, at least three feet away. Depending on the specifics of the sound system, the Acoustimass weighs at least 20 pounds. Bose produces several versions of the Acoustimass to correspond with various-sized sound systems, and does not recommend opening any of them on your own.
Unplug the Bose Acoustimass module from the both the stereo receiver and its power source.
Unscrew the screws holding the plastic grills in place over the speakers on the bottom of the module. This will allow you to remove the grills to replace them, or check the speakers.
Unscrew the speakers from their mounts, and pull them out. Depending on your Acoustimass module model, you may now be able to see inside the box.