How to Repair a Cracked Speaker Cone
Speaker cones can be damaged in many ways. Often they are bumped by people or furniture while being moved and this leads to tears or cracks in the cone. Some cracks develop simply because the speaker is old and brittle. Repairing your own speaker cones can save money. The cone is made from stiff paper or light cardboard, so it is easily fixed with items that you can find around the home.
Step 1 – Remove the Woofer
Unscrew and take the woofer out of the speaker box. Place the screws in a safe place so you don’t lose them. Disconnect the wires and measure the tear or crack.
Step 2 – Cut out a Patch
Cut out a piece of the construction paper to fit over the crack. Use a color of paper that is similar to the cone color to make the repair appear seamless. Try not to make the patch much bigger than the crack as a larger patch can compromise the integrity of the cone as well as affect the sound.
Step 3 – Glue the Paper Patch
Using the small paintbrush, dab a small amount of the adhesive onto the tear edges and place the paper patch on top of it. Hold in place for two minutes. Paint a thin coat of the rubber cement around the edges of the paper and allow it to dry. Make sure you cover the whole tear so there are no gaps.
Step 4 – Glue the Other Side of the Crack
Turn the woofer over and paint a coat of adhesive over the backside (inside) of the crack. Allow this to completely dry before testing the speaker with sound.
If the crack is thin and small, you can just stick the edges together with the rubber cement, without using a patch. This is a temporary job because a cracked woofer is probably old and will develop more cracks over time. A crack or tear means that the integrity of the cone is impaired and air will not move around it as designed. If you continue to use a cracked speaker, the crack will get bigger and the surrounding card more stressed. This can lead to even more damage.
Other ways to repair cracks is to use nail polish or any other glue that remains flexible after drying, like polyvinyl acetate (bought from craft shops). Super glue is not recommended because it stiffens the card and will leave it prone to breaking again. Be sure not to use too much of any adhesive or patch because the heavy spot will vibrate more and be more prone to damage.
Another option is to repair the crack with adhesive cloth repair tape. Make sure that the cloth is not too heavy and that you only use as much as you need so you don’t make a ‘heavy’ spot. This way, the sound will not be altered from your speaker and you can prevent further damage.