How Can I Test My Car Audio Subwoofer?
If your car audio subwoofer is not performing as intended, you should still be hesitant to dismiss it as broken. It is possible that your subwoofer can be fixed using simple techniques and cheap materials, or that it is actually out of commission. To determine which, you must test it.
First, remove the cover and play music using your car's audio system. If you see any damage to the subwoofer's cone, this is the source of your problem. If you do not, press down on the center and listen for a rattling noise. This indicates a blown coil. Last, connect your subwoofer to a 9-volt battery to see if it responds at all.