When you’re trying to listen to an amazing song or enjoy a movie on your home theater projector, nothing can ruin your fun as thoroughly as a blown speaker. The audio will either completely shut off or continue playing with the ever-present hissing accentuating every tone. Honestly, I’m not sure which option would be worse — having lackluster audio or not having any sound at all. With that in mind, I’ve decided to explain how to fix a blown speaker so none of us ever have to deal with these kinds of disruptions again.
Eventually, most speakers will malfunction in one way or another. Will it be less likely if you buy an expensive set from a reliable manufacturer? Sure. But even those kinds of products will deteriorate with time.
At that point, you’ll have two options. You can have a back-and-forth with the company to get them to replace your speakers. That may be the right choice to make if you paid an obscene amount of money for them only to have them blow out immediately. But if you consider yourself a bit of a handyman, you could easily fix the problem yourself.
How Do You Know If One of Your Speakers Is Blown?
Before we discuss the potential symptoms of having a blown speaker, let’s briefly talk about the anatomy of a speaker. Most speakers have a metal basket that holds the rest of its parts together. At the bottom of the whole thing, there’s a magnet with a voice coil suspended above it. The voice coil is, in turn, held by the spider, a circular disk that allows it to move up and down as it receives positive and negative charges.
On top of all that, we have all the external parts of the speaker, which include:
- A dust cap, which doesn’t have any effect on the sound of the speaker. Instead, the primary function of the protruding bubble in the center of the speaker is to prevent dust from entering the voice coil.
- A diaphragm, which is usually made of a stiff material, such as paper, plastic, metal, or fiber. The angled cone is the part that surrounds the dust cap and is affixed to the coil below. So it also moves up and down when the speakers are on.
- A rubber foam suspension surrounding the cone. The flexible ring that connects the cone to the top of the basket is otherwise known as the surround. It’s soft, allowing the cone to vibrate.
Generally, when people are talking about blown speakers, they’re referring to physical damage on one of these parts. It could be a rip in the soft foam surround or a more serious tear in the stiff cone. However, this damage can be accompanied by malfunctions in one of the hidden parts of the speaker as well.
So how can you tell the difference between a harmless rip and a more serious problem?
Symptoms of a Blown Speaker
There are different kinds of sound distortions you might hear if you really are dealing with a blown speaker. If the speaker is still playing audio, but you start hearing a hissing or buzzing noise underneath the sound, you may be dealing with a loose voice coil.
If you’re present at the moment when the speaker blows, you might hear a distinct popping noise. And if something has come loose, you might hear a rattling sound, not unlike the one the bass in your vehicle might produce.
As I have explained in the article I’ve linked to, sometimes inconsistent power surges can cause your bass to blow your speakers. That can make the voice coil overheat, which can physically damage the wires. If that happens, you can pretty much say goodbye to your speakers and start saving up for a new set or at least a replacement driver.
Another surefire way to tell if you have a blown speaker would be to gently touch the cone. If it’s not vibrating as it should, it may have gotten detached from the coil. Furthermore, if other sound dimensions are missing, e.g. a certain frequency range is completely gone, the damage may be more extensive than you originally thought.
Most of the time, you’ll be able to tell at a glance if your speakers are blown, at least if nothing is blocking your line of sight. More importantly, it shouldn’t take you long to fix them once you order the tools and replacement parts you need.
Step-By-Step Guide to Fixing a Blown Speaker
Fixing a blown speaker isn’t a one-size-fits-all kind of thing. Everyone does it in their own way. Some inexplicably do it with needle and thread, which seems a bit implausible to me. But hey, if it works, it works!
However, if you’ve never fiddled with your speakers, you may not even know where to begin. Well, you’ll find a comprehensive guide right here.
1. Find the Blown Speaker
The first step, as always, is determining which of your speakers is causing the noise. If you’re dealing with a regular home speaker set, you’ll be able to see which of the speakers needs repairs. However, if the speakers have a cover or a grille you don’t want to take off unnecessarily, there are other ways to find the malfunctioning one.
For example, you can simply disconnect each of the individual speakers from the subwoofer one at a time. Eventually, you’ll find the black sheep by listening for the symptoms of blown speakers I’ve mentioned above.
On the other hand, if you’re working with a speaker set that’s not as easy to disconnect, you could use the equalizer. More specifically, you’ll need to find the balance control feature. So if you suspect that one of the speakers in your vehicle has blown, try to shift the balance from the left-side speakers to the right to see where the noise is coming from.
You could also turn up the volume slightly to hear if the noise will worsen. Don’t overdo it — that could blow one of the other speakers.
And, of course, you’ll have to play something while you run this test. I recommend sticking to tunes you know by heart. That will allow you to hear any discrepancies caused by the speaker’s damages.
2. Find the Problem
Once you have a viable suspect, you’ll want to double-check if that’s the one you’re looking for. If you can’t examine the surround and the cone because of a faceplate, carefully unscrew it. Some speakers have fabric covers, which you’ll have to loosen without tearing them. After you get it off, you should be able to see rips or at least feel that something isn’t right by gently touching the cone.
If your suspicions were correct, it’s time to take the speaker out of its case, whether that’s a simple box or the car door. But first: remember to turn the car completely off or unplug the speaker from the electrical outlet.
Before you get the driver out of its case, you’ll have to detach two wires. They’ll probably be red and black and similarly labeled on the driver itself. If they’re not, make sure to mark which wire went where. If you cross them later, the speaker will sound really strange, to say the least.
Once you have the driver in the palm of your hand, the first thing you should do is sniff it. You read that right! If the coil is overheated or melted, you should be able to smell it. If you detect a burnt odor, you may have to order a new driver or at least recone the speaker.
3. Prep the Area and Order Replacements
After taking a quick look at the speaker you just took out, you’ll have to clean it. It’ll probably have months if not years of dust on it. But a quick wipe-down with alcohol-soaked pads and cotton swabs should do the trick.
When you have the speaker squeaky clean, you can finally check out the damage. If the surround is torn, you’ll have to order a new one. Speakers generally come in standard sizes so you should be able to find the part you need easily. Before you look anywhere else, check if the manufacturer of your speakers sells replacement parts.
If you buy a foam surround repair kit, it may include an adhesive and a brush as well. You’re going to use those to attach the foam to the cone after cutting and scraping away the previous surround.
But if the cone is torn, you’ll have to patch it up somehow or buy a new one. And that can be more expensive than you’d think. Since the cone is connected to the voice coil, you’ll essentially have to buy a whole new driver.
4. Install the New Surround
When your new surround arrives, you’ll have to remove the previous one completely before you stick it on. You can scrape off the foam residue with a scalpel or a razor before soaking the cone and the basket edges with 70% isopropyl alcohol to get rid of those last traces of glue. Once everything is clean, you can smear your adhesive on the inner lip of your new surround and attach it to the flat outer edge of the cone.
Once that cures, you’ll have to attach the outer lip of the surround to the basket without moving the voice coil. There are two ways to make sure that the voice coil stays put while you do your thing. If you get a dust cap replacement as well, you can do the shim method like the guy in this video.
You’ll need to take the existing dust cap off without damaging the cone, then slide thin plastic shims on all sides of the coil. When the outer lip of the surround cures, you can take the shims out and put in the new dust cap.
On the other hand, if you don’t want to go to the trouble of putting in a new dust cap, you can play a low-frequency tone through the speakers while you center the outer lip of the surround as demonstrated in this video.
5. Patch the Cone
If you have a rip in your paper cone, you can just use paper to repair it. It’s a great quick-fix for tears of all sizes, but not really a permanent solution if you’re looking for peak performance.
In any case, if you want to try it out, you’ll need a paper tissue and Elmer’s glue. Separate a layer of the tissue and rip it to your desired dimension. As you’ll see in this video, ripping is better than cutting because it allows the paper to blend into the cone.
Holding the paper in your hand, soak it with the glue until it’s nice and mushy. Then, apply to the tear in the cone. If possible, do the same thing on the bottom side of the cone. After it dries, you can hit it with a flat or matte black spray or leave it as is, if you don’t mind the haphazard appearance.
I’ve also seen people use a similar method but without the tissue. They dilute glue with warm water and use a painter’s brush to apply the mixture directly to the cone. When it dries, the cone should be a bit stiffer, and any small tears should be fused. However, that probably won’t do the trick if you’re dealing with larger tears.
6. Recone Your Driver
The most invasive thing you can do to fix your speaker would be to recone it. That means that you’ll need to cut out the cone, coil, and spider before implanting new ones and topping it all off with a new surround. It’s a great solution if more than one of those parts are damaged. But before you order all those parts, you should consider the cost.
If you’re trying to salvage expensive Hi-Fi speakers, sending it to a repair shop or installing new parts yourself may be more cost-effective than buying new speakers. It allows you to skirt the cost of the metal basket, magnet, and speaker box. But if the replacement is more expensive than the speakers were, just buy a new set instead.
7. Do a Speaker Test and Reinstall the Driver
Finally, before you put the driver back into the speaker box or your vehicle, you’ll want to do one final test. It’ll essentially be the same frequency test we saw in one of the videos I’ve linked to above. After making sure that the driver is fully functional, you can reinstall it, making sure to hook the wires into the proper connectors.
Get Back to Blasting Your Tunes
As you can see, there are different ways to fix your speaker, even if it appears to be beyond repair. Now, you just need to make sure they don’t blow again any time soon by:
- Not maxing out the volume. Remember, overpowering your speakers can lead to anything from surround tears to coil damage.
- Getting a subwoofer. Don’t put all the pressure on your regular drivers when a subwoofer can provide a much richer sound.
- Soundproof the room or your vehicle, so you have an easier time hearing the speakers in the first place.
But even regular use can eventually lead to this kind of wear and tear. Fortunately, you now have all the tools you need to deal with the next blown speaker you encounter.