How To Fix A Blown Subwoofer

by Matthew David | Updated: 09/13/2023

How To Fix A Blown Subwoofer

You’re watching the climax of your favorite action movie, waiting for that big explosion scene you know is coming. As it hits, you expect your subwoofer to rumble and boom, putting you right in the middle of the action. But instead…nothing. Or maybe just a sad little buzzing sound. Uh oh.

We’ve all been there – when your subwoofer goes kaput at the worst possible moment. It’s enough to ruin your home theater experience. But before you shell out big bucks to replace your sub, good news: you can often fix a blown subwoofer yourself with a few tools and some DIY determination.

In this guide, we’ll walk through the steps to diagnose a blown subwoofer, make simple repairs, and get your home theater’s bass back in action. Let’s get started and fix that sub!

Signs Your Subwoofer Is Blown

First things first – how do you know for sure if your subwoofer is blown? Here are some telltale signs:

No Sound

If your subwoofer isn’t making any sound at all, the problem could be as simple as a loose wire connection. But if the wiring checks out, chances are the sub has blown. Total loss of sound is a common symptom of a fried subwoofer.

Distorted or Scratchy Sound

If your sub is still producing sound but it’s distorted, scratchy, or generally lousy, the speaker is likely blown. Damaged subwoofer parts like the cone or voice coil will warp the sound quality.

Buzzing Noise

A buzzing sound coming from the subwoofer is usually caused by a damaged voice coil. Picture an exposed wire touching the inside of the speaker – that’s the sort of buzz you’ll hear. Very annoying!

Using a Multimeter to Test Resistance

For a definitive test, use a multimeter to check the electrical resistance across the subwoofer’s terminals. A normal reading is around 2 to 8 ohms. A 0 or infinite reading means the sub is blown.

So if you’re noticing any of those issues above with your once booming sub, chances are it’s blown. Now let’s look at your repair options…

Should You Attempt A DIY Repair?

Before you dig in to trying to fix it yourself, decide – is it worth tackling a subwoofer repair DIY? Here are a few things to consider:

Analyze those factors as you decide whether to repair or replace your blown subwoofer. Now let’s look at what you’ll need…

Materials Needed for Repair

If you decide to take on a DIY subwoofer repair, gather these supplies:

Screwdriver Set

You’ll need standard screwdrivers to open up the speaker cabinet and remove components. Pick a set with multiple sizes like this 16-piece one.

Air Compressor

Use compressed air to clean dust out of the subwoofer interior once you have it open. Canned air works for this too.

Putty Knife

Use a putty knife or paint scraper to pry off the speaker surround without damaging it.

Glue/Adhesives

You’ll need new adhesive to reattach the speaker surround, cone, and other parts. A hot glue gun is perfect for this.

Microfiber Cloth

Have some microfiber cloths on hand to wipe down the sub’s parts and cabinet without scratching them.

Advanced: Heat Gun, Multimeter, Soldering Iron

More advanced tools like a heat gun, multimeter, and soldering iron allow you to tackle more in-depth repairs by testing components, removing adhesives, and re-soldering connections.

Okay, you’ve got your gear. Now it’s time to dig in!

Steps for Repairing a Blown Subwoofer

Here is the basic process to resuscitate a blown subwoofer:

Remove Subwoofer from Enclosure

First up, it’s teardown time. Unplug the sub and use a screwdriver to remove it from the speaker cabinet. Save all screws and parts!

Test Voice Coil with Multimeter

If you have a multimeter, test the subwoofer’s voice coil for resistance. If the voice coil is blown, replacement will be needed.

Remove and Replace Damaged Voice Coil

If the voice coil is toast, carefully remove it and disconnect the wire terminals. Install a new voice coil, taking care to center it properly.

Remove and Replace Torn Speaker Cone

Pry off the speaker surround and remove the cone. Install a fresh replacement cone and use adhesive to reattach the surround.

Reassemble with New Components

Once you’ve replaced any damaged parts, carefully reassemble the subwoofer and reconnect the wiring.

Test Audio and Reinstall Subwoofer

Give your repaired sub a test listen before you screw it back into the cabinet. Get your bass bumpin’ again!

That covers the basic repair process, though the exact steps can vary for different subwoofer models. Check Youtube for repair videos specific to your sub’s make and model for tips.

Now let’s talk about how you can prevent blowing out another subwoofer in the future…

Preventing Future Subwoofer Blowouts

No one wants to repeat these repairs every 6 months. Here are some tips to keep your subwoofer going strong:

Follow those guidelines and your repaired or new subwoofer will deliver bass bliss for years to come! Now let’s compare some repair vs. replacement pros and cons.

Pros and Cons of Repair vs Replacement

Should you repair or just replace your battered subwoofer? Here are some factors to consider:

Repair Pros

Repair Cons

Replacement Pros

Replacement Cons

As you weigh repair vs replace, factor in cost, performance, and sustainability. Now let’s answer some common questions.

FAQs

What are the main causes of a blown subwoofer?

Overpowering, improper impedance matching, and prolonged high volume are the most common causes of sub failure. Physical damage like punctured cones can also lead to blowout.

How can I test if my subwoofer is blown?

Use a multimeter to check resistance on the terminals – a zero or infinite reading indicates a blown sub. Also listen for distorted sound, buzzing, or a complete lack of sound.

What tools do I need to repair a subwoofer?

Basic repair tools include screwdrivers, adhesive, compressed air, a putty knife, and microfiber cloths. For more advanced repair, you may need a soldering iron, multimeter, or heat gun.

Where can I find replacement parts for my subwoofer?

You can find replacement subwoofer parts like cones, voice coils, and surrounds at online retailersParts Express, Simply Speakers, and Amazon. Match your original specs.

How long does a subwoofer repair take?

Simple DIY subwoofer repairs can be completed in 1-2 hours. More complex repairs involving soldering or voice coil replacement may take 4-6 hours. Allow additional time for adhesives to fully cure before reassembly.

Is it worth trying to repair my subwoofer?

For vintage/high-end gear or simple fixes, repair may be worthwhile. But for extensive damage requiring significant cost, replacement may be a better option. Evaluate your repair skills and budget.

What can I do to prevent blowing subwoofers in the future?

Proper power matching, gain structure, speaker break-in, and thermal management will help avoid over-stressing your subwoofer and prevent failures down the road.

Should I just replace my subwoofer instead of repairing?

If the damage is severe and replacement parts are readily available for your model, replacement may be easier than a complex repair. But reused vintage gear often sounds better than new!

Are repair kits a good option?

For minor subwoofer repairs like a torn surround, inexpensive repair kits can work great. But they may not provide all you need for complex voice coil or refoaming jobs.

How do I reinstall a subwoofer after repairing it?

Once your sub is repaired, slowly break it in over 10-15 hours. Reinstall in the enclosure using the original hardware, reconnect wiring carefully, then calibrate level and crossover settings.

Conclusion

As you can see, with some DIY determination and the right tools, a blown subwoofer doesn’t have to spell doom. In many cases that treasured old sub can come back to life with fairly simple repairs. Just be sure to address the underlying issues that caused the failure so you don’t end up repeating the repair in short order.

While subwoofer replacement may sometimes be the easier route, fixing your existing gear often costs far less and keeps old speakers churning out the bass. Hopefully this guide has demystified the process of diagnosing issues and provided a solid roadmap for getting your sub back up and running. Happy bass making!