How to Tell if a Subwoofer Car Speaker is Blown
You are jamming down the road listening to your favorite tunes and all of a sudden, a car speaker goes out. Now you must figure out which speaker it is. You will definitely know that it's not a tweeter car speaker if your bass is gone. Upon closer inspection, you realize you may have blown car speakers and your subwoofer is most likely the problem. There are some simple ways to confirm this.
Step 1: Test Connection
You don't want to go through the expense of replacing a piece of equipment only to find that the problem is just a broken or bad connection. Test the connection by removing the wires from the amplifier and attaching the two speaker wires to a 9-volt battery. Listen for a brief popping sound from the speaker being tested. Ensure the speaker cover is off so that you can observe the speaker cone. If the cone moves, then the problem is with the connection and not the speaker. If you don't have a 9-volt battery, you can use an ohmmeter or a multimeter to check the speaker. Set the meter to read ohms if you're using a multimeter. If you're just using an ohmmeter then you don't have to do anything. You must ensure that the speakers are off. Touch the lead to each terminal on the speaker. If you get a reading of 1.0 ohms, then the subwoofer is fine and your problem lies elsewhere. If your ohms read infinite, then you have a blown subwoofer.
Step 2: Listen for Crackling or Distorted Sound
If the bass is not crisp sounding at all levels, you have a problem with the subwoofer. Start at a low volume and slowly raise it, not above medium, until you note that the speaker is having difficulty producing the familiar crisp sound you're used to. If the sound is distorted, then the subwoofer is partially blown and will soon need to be replaced. If you hear crackling being produced by the speaker, then this is a sure sign of a blown subwoofer. The crackling sound is produced when the car speaker voice coil separates from the speaker cone.
Step 3: Determine the Extent of Damage
Once you have determined that there is a problem with the subwoofer, you will probably want to know how badly it's damaged. Visually inspect the speaker for holes, tears or splits. If the damage is minor, you may be able to repair it with a sealer specifically designed for this problem. If it's catastrophic, then it's time to go shopping for a new car speaker.
These are some easy methods you can use to determine if your subwoofer is blown. The best way to prevent killing your car speakers is to be careful while operating your system and be mindful of overdoing the volume.