Skip to Content

How to Fix Dented Speaker Dust Cap?

If you’re a car driver and music enthusiast, you know that having great speakers is a must. But what happens when your speaker’s dust cap becomes dented?

Luckily, it’s not the end of the world. There are ways to fix it, but how do it properly? Let’s find out.

To fix dented plastic speaker dust cap, use a heat gun or hairdryer and a vacuum cleaner. Once warmed up and softened, use a vacuum cleaner and press gently to push the dent out. To fix a paper dust cap, stick the sealing tape to the dented area and gently press out the dent.

As an Amazon Associate, ImproveCarAudio will receive a small commission from qualifying purchases made through the links in this article.

Tip: If any fixes don’t work, replacing your dented speaker dust cap with a new one may be necessary.

To do this, find a matching replacement cap (link to Amazon), and follow the instructions provided by the manufacturer. With proper care and maintenance, your speakers should last for many years without repair.

In the article below, I will go into more detail about repairing different types of dust caps.

What Does a Speaker Dust Cap Do?

According to Wikipedia“The dust cap (also known as dust dome, or dome) is a gently curved dome mounted either in concave or convex orientation over the central hole of most loudspeaker diaphragms.

It protects the inner mechanics (such as the pole pieces and the voice coil) from tiny particles (which can cause rubs) and other contamination”.

Most dust caps are made from the same material as speaker cones, but there are also speakers with paper cones with plastic or aluminum caps. Thin aluminum is used most often in tweeters.

Some speakers, like active subwoofers, have accelerometers inside the voice coils, and dust caps are a must for these types of speakers.

how to repair car speaker dust caps

Some speakers, like active subwoofers, have accelerometers inside the voice coils, and dust caps are a must for these types of speakers.

Dust caps also protect voice coils and all wires inside the speakers. It is crucial to protect the center of the speakers from any contact with foreign objects.

Remember, do not ever touch the inside of a running speaker; it can destroy the speaker to pieces, especially powerful subwoofers. Also, I do not recommend tapping on the running cone, especially with something sharp.

Does Speaker Dust Cap Affect Sound?

The reason to have dust caps in the speakers is not only decorative; it has a significant impact on how the speaker will sound. This is because dust caps act as an acoustic filter, absorbing high-frequencies from inside the speaker.

When there is an air gap between the cap and speaker cone, or when the cap is missing, you can hear the “chopping” like sounds.

The chopping effect is caused by the air going through the speaker between the cone and a magnet.

Strange sounds are especially noticeable in subwoofers mounted in box enclosures and where there is not much room for airflow, and they are similar to bass-reflex in the box.

Dented caps on the tweeters do not affect sound quality if the damages are minor.

But when the cap in the tweeter is collapsed, the tweeter may be damaged, and when you can hear raspy voices, that means either the tweeter or the whole car speaker has to be replaced.

Make sure your speakers always have dust caps on them, and they are correctly sealed. Below are a few steps on how to fix or replace them.

How to Fix Speaker Dust Cap?

If the covers on the speakers are dented, that does not mean you have to throw the speaker away.

The good news is that there are a few ways to fix a dented dust cap. Of course, the best way to fix a speaker dust cap is to use a heat gun or hairdryer and a vacuum cleaner, but for more details, let’s go one by one:

Fixing a Small Dent with a Vacuum Cleaner and Hairdryer

If you have a small dent in your speaker’s dust cap, you can try fixing it with a vacuum cleaner and hairdryer.

#1. Make sure the area around the dent is clean.

#2. Put the vacuum cleaner over the top of the dent and turn it on. The suction will help to remove the dent.

#3. Hold the hairdryer on low heat over the area for 30 seconds to 1 minute. This will help to smooth out the area.

#4. Use your fingers to gently press the area back into place.

Fixing a Large Dent with a Heat Gun

If you have a large dent in your speaker’s dust cap, you can try fixing it with a heat gun.

#1. Make sure the area around the dent is clean.

#2. Hold the heat gun about 6 inches away from the area and turn it on.

#3. Move the heat gun back and forth over the area for 30 seconds to 1 minute. This will help to soften the plastic.

#4. Use your fingers to gently press the area back into place.

Those steps are similar when using a hairdryer, but you need to be more careful with a heat gun because the heat is much hotter. But, again, keep the heat gun in one place for a short time, or you could melt the plastic.

Below are a few methods depending on the material of your speaker’s dust cap.

Fixing Dented Paper Dust Cap

Paper caps are the easiest ones to be fixed. The most effective method for me is to use a vacuum cleaner and suck the dent cap out of the cone.

This method works well, but when you have a vacuum hose too close to the cap, it can rip off the dust caps from the cone, so be careful and do not use too much sucking pressure.

Sometimes after fixing paper caps, you may see some wrinkles on the surface. Wrinkles do not affect music quality, but for me, they do not look nice, and I would instead paint them with a black permanent marker, or if they still do not look good, replace them.

Fixing Dented Plastic Dust Cap

To DIY repair dented plastic caps, you will need a hair blower and a vacuum cleaner.

#1. Start with blowing hot air over dust caps. Make sure you blow air in circles over the entire plastic cup and not over one point.

Having equal temperature on the whole surface will prevent further deformation of dust caps.

Different temperatures on the plastic can cause permanent deformation, so be careful not to overheat one side of the cover.

While warming up the cap, you can gently touch the plastic to check the surface temperature because you do not want the cover to melt. When touching, you check if the cap has softened across the whole area, but do it gently.

#2. As soon as the plastic cap is hot and soft, the next step is to use a vacuum cleaner and suck a cover from the cone. Do not touch the hose to the cup when you use a strong vacuum cleaner or if you can, reduce the sucking pressure.

Although too much power can rip off the cup, you must place a hose close enough to the cover so that air can suck the dented cup slowly to its original form.

Another way to repair dented domes is to use solid, sticky tape. Just stick tape to the dented area and try to pull it off. It may not work the first time, but after a few trials, the dust cap should return to its original form.

This method helps in many cases and is especially good for soft plastics in tweeters, where the vacuum hose may be too big.

To ensure that pulled domes have a nice smooth surface after the repair, you can use a hair blower to warm up the covers. Also, heating plastic may help the material structure return to its original shape.

Fixing Dented Metal Dust Cap

Aluminum caps are the strongest of all types used in speakers, and because they are stiff, repairing them is most difficult. Even if you can pull off the cap, its surface will still have visible marks and creases.

The better and faster way is to replace aluminum caps with new ones. It will take less time than trying to repair them, and the final effect will be much better.

How to Replace Paper Dust Cap on Speaker?

If your speaker’s dust cap is severely damaged or can’t get the dent out, you may need to replace it altogether. You can purchase replacement dust caps online or at some electronics stores.

When you want to replace paper caps on your speakers, the steps below will help you do it quickly and without any problems.

Below I recommend a few simple tools that are available in any store. But, if you want them quickly, click the links and check them out on Amazon.

#1. A sharp blade knife or scalpel

#2. Mounting Tape

#3. Glue

The whole replacement is easy, and it should not take more than 10 minutes, so let’s start:

#1. Use a blade knife and cut through a damaged dust cap close to the original glue line. Keep a blade short to prevent any damage to the speaker cone or the line wires from the voice coil.

#2. Remove any leftovers from the removed cover and ensure the cone’s glued area is clean and smooth without any debris on the surface.

#3. Place a new dust cap on the cone and hold it in place. An excellent way to hold and place a cap in the center of the cone is to use masking tape.

#4. Stick the dust cap with the speaker cone using, for example, MI 2000 adhesive. Next, apply a thin layer of glue all around the edge, making sure there are no gaps left that may cause further not needed noises.

#5. Leave the speaker with a replaced dust cap overnight in a ventilated and not too cold place to ensure the glue will dry, and the cap will not move around.

After any repairs, I left my speakers in the garage overnight, and by the next morning, they were like new.

Remember to keep the repaired driver with the cone facing the ceiling while replacing a dust cup. This way, you will keep a cap in the center of the speaker without any risk of moving it before the glue is dried.

How to Replace Aluminum or Plastic Dust Cap on Speaker?

The steps to replace plastic or aluminum dust caps are the same as for paper caps. The only difference is for glue the cap with the speaker cone.

You will have to use thicker glue than for paper caps and glue the area before locating a new cap in place. Also, use the thicker layer of glue to properly seal a dust cap with a cone.

The good elastic glue for plastic and aluminum caps is Adhesive Black Rubber Cement, but it cannot be too stiff.

How to Protect Dust Caps From Being Damaged?

Speaker dents are mechanical damages; to avoid them, ensure your car speakers are always covered with grills. Twitters are especially sensitive to any contact with hard or heavy objects, therefore their repair may not be possible when damaged.

If your speakers are not equipped with original grills, there are many aftermarket options available to choose from.

Many subwoofers placed in the trunks do not have grills and are also at risk of damage. To protect them from any mechanical impact, make sure there is nothing close to the speakers that can damage them.

Conclusion

Fixing a speaker dust cap is not difficult, and you can do it by yourself at home without any particular skills. The most important is to have all the necessary tools and materials before starting the work.

If you are unsure how to replace or repair a speaker dust cap, it is always better to contact a professional for help. They will know how to properly fix your speaker without damaging it.