How to Tell if a Subwoofer is Blown: An Info Guide

How to Tell if a Subwoofer is Blown
11th Dec,2019

You’re driving and grooving to the music when suddenly your subwoofer doesn’t sound like it did before. What happened? You followed our advice, perhaps picked out one of our top choices for 8-inch subwoofers, but it isn’t sounding right… Speakers get blown for various reasons, from poor care to too high of an intensity for over long periods of time. It took a lot of time to put the speaker in in the first place, and now you might have to take it out all over again to assess the damage. The process can range from easy to difficult, and that depends on the damage.

Why is My Subwoofer Blown?

The biggest question you may have is why your subwoofer blew out. Maybe you think you take care of it, but that may not necessarily be the case. Whether you play it too loudly or too quietly, either way it could be the reason why your sub blew out. The highest rating of power isn’t meant to be enforced for over long periods of time. Some people tend to think they can blast their subwoofer for long periods because it says it can handle it… you’d be better off if you install a subwoofer to a factory stereo. What many people don’t know is that the highest power rating is actually for playing in intervals. 

Once you overpower your speaker, the voice coils get damaged by getting pushed too far and getting separated from the spider. Once it’s torn, it might create a low buzzing sound or it might not create any sound at all. That’s when you know your speaker is blown. 

On the flipside, if you underpower your speaker, it can also damage the subwoofer as well. It could cause overheating, and jamming the voice coils. Just make sure you are powering your subwoofer at optimal levels. 

How to Check My Blown Subwoofer

After you’re sure the subwoofer is blown, there are a couple of things you can do to diagnose the problem. While tearing and voice coil issues are the most common, there could be more difficult problems you might face as well.

Blown Coil

To check whether or not it’s a blown coil, you can connect the terminals of the coil to a multimeter just to check whether everything is working fine. 

Speaker Cone

If the voice coil is working fine, or not since some subwoofers can blow in different areas, the next step is to check the speaker cone. The speaker cone should have flexibility as it works on a suspension system. This also makes it easy for it to tear. Just remove the cover of your sub and gently test the movement of your cone. If it doesn’t give much leeway, this could be due to a jammed or broken voice coil. The next step is to check it for holes and rips.

If indeed there is a tear in the cone or the foam, replacing it is easily done in under 30 minutes with the right parts. However, if not only one of the voice coils, cone, and spider are broken, then you have your work cut out for you. It could take 2-3 hours and sometimes the parts to fix it plus the kit could cost as much as the speaker/subwoofer itself… you’ll always have the option to see our recommendations in any case.

Using Things Around the House and Fixing Your Blown Subwoofer

You can rummage around the house and find some loose materials you could use to patch up the speakers.

Stuck Voice Coil

If you have a stuck voice coil, grab a flashlight and try to push it back into place gently. Test it out after you have fixed it to see if it works.


Tear repair can be significantly more difficult. Most of us have paper towels and glue at home, so this is something you could whip together quickly for an easy fix. Apply glue on a small piece of paper towel that will be used to cover the hole. Make sure you smooth down the paper towel for a seamless patch job.

Foam Surround

If the foam surround is broken, you need to separate the gasket from the frame in order to fix it. Cut the damaged foam off of the speaker and make sure you get all the smaller parts. Use rubbing alcohol to remove all the residue. This is when you can install the new foam surround. Apply glue where the old foam surround sat, then gently push and fit the new foam onto the glue. Wait for the glue to set, then reinstall the gasket.

Speaker Cone and Coil

Remove the speaker cone and cut out the spider and remove the voice coils. Remove the gasket and clean off any debris. Remove wires and solder from the speaker basket terminals. Position the new coil so it lines up with the terminals. Glue the spider back in place with just a bead or two of glue. Apply more glue to where the gasket sat, and put the cone into place. The lead out wires should then be placed flat against the cone, you can cut any remnants that are hanging out. Remove the shim and tin and solder the two lead wires then thread them through the holes. Then place the cone and dust cover back on and then place the lead wires in the basket terminals and then solder. Glue down the gasket again and then you’re done!

The last step is to obviously replace the speaker back in its holding and test it out!


The first part of dealing with a subwoofer is to test to see if it’s really blown. If so, your next step is to diagnose which part of the subwoofer is damaged. Then afterwards you can readily deal with the issue, whether it be with material you have around the house for a quick fix, or if you decide to replace the part altogether. Keep in mind that it could sometimes cost you more to fix an old subwoofer/speaker that you could just replace with a newer option—come and check out our Best Shallow Mount Subwoofers for recommendations.

William Johnson

William Johnson is the owner and founder of He writes about car accessories, with his passion stemming from a deep enthusiasm for all things automotive. His website, RRD, focuses on in-depth reviews of car accessories to help people find the best and latest products in the market.