How To Repair A Subwoofer? - Instructions

Are you suffering from a faulty subwoofer? And thinking about replacing it? Well, before you rush out and replace them, why not try repairing them on your own? With this article, you’ll know how to repair a subwoofer. 

Speakers and subwoofers are a vital part of our car sound systems, whether they’re stock (bought with the car) or an aftermarket upgrade. In this article, we’ll show you how to repair them when they go wrong, saving hundreds of dollars on repairs at your local mechanic.

They are added to a car’s speaker system to reproduce frequencies below the other speakers’ handle.

How To Repair A Subwoofer?

How To Repair A Subwoofer? by

All you need is some tools and ingredients that almost everyone has lying around the house! Cut open your old subwoofer, and you’ll find several different parts: usually, an empty metal box, a broken piece of paper cone attached to a metal coil and some screws.

If you like tinkering in the garage, saving money on car fixing costs and enjoy being creative, this is ideal for you! Here’s how to repair a subwoofer.

Tools Required

  • Tape measure (meter stick)
  • Screwdriver
  • Glue
  • Scissors
  • Materials required:
  • Cardboard box from a more significant item like a printer or washing machine (if you don’t have anything important enough, it’s worth popping to the shops to buy one)
  • Old newspaper/magazines (don’t use glossy pages as they may catch on fire)
  • Enough cotton to fill your empty subwoofer box (this can be obtained from an old pillow, mattress or teddy bear)
  • Needle and thread
  • Black marker pen

Repair A Subwoofer: Instructions

How To Repair A Subwoofer? by
  1. Measure the entire length of the paper cone that is attached to your broken subwoofer. Write this measurement down somewhere – it’s essential you stick to it when making a replacement cone!
  1. Cut out two pieces of cardboard that are the same size, one slightly smaller than the other (make sure they’re big enough to fit over the paper cones inside your subwoofer box).
  1. Draw a circle on one of the pieces of cardboard that is the same circumference as your original cone. Cut it out to make a perfect circle.
  1. Draw an oblong onto one piece of cardboard that’s slightly longer than your cone but not quite as wide (so it will fit inside the box). This will form the top/bottom of your new cone.
  1. Cut out the shape you’ve created, then tape it together using sticky tape or clear nail varnish to form a bag (there needs to be enough room in here for you to cram all of the cottons once it’s shaped). You should have one large circle and one long oblong taped together.
  1. Put a sheet of paper towel inside your bag and fill the rest with cotton (you may need to use an old pillow or teddy bear for this – if so, make sure you remove all of the stuffing). 

          Once it’s complete, tie off the top with a tight knot to stop any cotton from escaping.

  1. Put this bag inside your smaller piece of cardboard (i.e. the circle) and fold it down at one side to create an opening so you can pour in glue later on.
  1. Prepare your broken subwoofer by removing its paper cone, coil and screws/nuts that hold everything together snugly. If there’s any paper cone left at the bottom of your unit, pull it out to reveal more space for cotton. You must also ensure the coil stays attached to the cone when you remove it (it just needs to be free from its plastic holder).
  1. Put one of your cones inside your subwoofer box where the old speaker was and screw it into place. Make sure you use a screwdriver to tighten up the screws as much as possible to hold the cone in place (don’t worry about any glue that squeezes out).
  1. Fold your replacement paper cone bag and pop it inside, making sure to secure it with tape/nail varnish so you can glue it down in the next step.
  1. Squeeze out some glue around the inside of your cone and on top of the cardboard circle. You can use a small brush to spread this evenly if you like. Allow everything to dry before moving onto the next step (if you’re impatient, put it under a weight on top of something and let it dry overnight).
  1. While your cone is drying, wrap some glue-soaked cotton around your coil (if there isn’t any left in the bag, you may need to pull some out from an old pillow or teddy bear – make sure you remove all of the stuffing). It should look like a small cotton doughnut, but one long enough to stretch around the coil. Allow this to dry, too, then trim off any excess cotton with some scissors.
  1. Trim down your replacement cone so it’s slightly longer than the original, then glue it into place (while it dries, put a heavy object on top of it, so you don’t have to use your hands). When it’s dry, cut the excess paper off around the base of your amp. This should now be a good-as-new subwoofer!
  1. If necessary, reattach your coil and screws/nuts before fitting everything back together in your speaker box (if you’ve glued the cone in, it may get a little more complicated).
  1. If everything works properly when you plug your subwoofer back into the mains, pat yourself on the back and enjoy your work! Otherwise, go through any steps you missed to resolve this issue. Once it’s working perfectly again, give yourself another pat on the back (or two – you’ve earned it!).

Is It Worth Repairing A Subwoofer?

The short answer to this question is no. The repair is likely not worth it. 

How Do I Ensure My Repairs Are As Substantial As Possible?

By making sure that the coil is fully attached to your subwoofer’s paper cone, that you remove all of the old glue from both parts before applying new glue and using a heavy object while they dry. You may also want to check out this guide for more information on how to repair speakers:

How Do I Stop A Subwoofer From Shaking?

How To Repair A Subwoofer? by

If the unit is new, there may be something wrong with it. If that’s not the case, consider placing the subwoofer on top of a coaster or another piece of soft material to dampen the vibrations.

Checking the wire connections first and making sure you have all your screws/nuts in place (tighten them as much as possible with a screwdriver) should also help prevent shaking or other issues.

How Do I Fix A Subwoofer That Only Makes Buzzing Noises?

How To Repair A Subwoofer? by

This can be caused by a loose wire connection or something rubbing against the cone (including excessive dust build-up). You may also want to clean out your unit with compressed air and check all of the connections are tightly in place:

How Do I Stop My Subwoofer From Making A Humming Noise?

Place it on top of something soft, like a coaster or another piece of material, and check all wire connections inside. You may also want to check out this guide for more information on how to deal with humming speakers:

Well, there you have it. If I’m honest, this was an article that I struggled with for a while, and the best solution was to take several articles from public forums and put them together as one article. After all of that hard work, I hope you found it helpful! Any questions or comments? Leave them below, and I’ll get back to you. Thanks for reading!