4 Reasons Your Subwoofer Stopped Working and How You Can Fix Them
“Forever no longer exists,” say the new generation lovers. It may not be true at all times, but when we talk about gadgets, it may be 100% applicable.
For our subwoofers, no matter how expensive or cheap it may be, a day will come when you will key in “subwoofer not working” in your search bar.
There are many reasons why it does so, but I will give you the four most common. But before that, it’s a good idea if you know the anatomy of a subwoofer and how each of the parts works.
Basic Parts of a Subwoofer
- Cone. This part is also called the diaphragm and can be made of different materials—paper, plastic, cloth, etc. Its primary function is to push and pull air to create sound waves.
- Surround. This flexible part of the subwoofer is what keeps the cone in place, allowing it to move in and out. It is attached to the subwoofer basket and is usually made of rubber, polyester or foam.
- Spider. Another part that ensures the cone doesn’t move out of its place is the spider. It is usually made of stiffened fabric.
- Voice coil. The voice coil is the electromagnet of the speaker, creating positive and negative poles and attracting or repelling the subwoofer’s permanent magnet. It is made coils of wire, copper or aluminum, wrapped around a metal called a former.
- Magnet. The magnet is found at the bottom of subwoofer basket. It’s reactions attract or repel the electromagnet is what drives the cone to move in or out.
Reasons a Subwoofer is Not Working
- Damaged cone. The usual cone movement may cause tearing of the cone materials especially if the motion is abnormal. Also, age engenders wearing; hence, it is not unusual to see scratches and cuts on the cone surface. The cone may also be detached from its surround.
- Damaged voice coil. Because the voice coil receives the current from a power source, it has the tendency to heat up. When this happens, it can melt the former, the wires, or the glue that keeps things in place. Consequently, the electromagnet capability of this coil is diminished or gone permanently.
- Shorting. Short circuit condition is one of the three electronic malfunctions that can happen in your car. This usually happens when two bare wires get in contact with each other when they are not supposed to.
- Lack of power. As mentioned earlier, a short circuit may cause this condition. Aside from that, it can be that the amplifier’s power rating does not match the subwoofer’s power handling. In other words, it’s underpowered.
When any of these happens, the cone movement may not send the air to where it belongs. It may also cause inaccurate resistance, which will make the spider or entire speaker move too fast.
As a result, the signal that’s supposed to reach the subwoofer may not get to its destination or the amount of power may not be enough. In other cases, it may also cause power overload which can melt subwoofer parts.
When the voice coils do not get enough juice, its electromagnetic strength may not suffice for it to interact properly with the magnet. And when the magnet does not attract or repel, the cone does not move as well. It’s a domino effect.
How to Fix a Subwoofer
A dysfunctional subwoofer requires different solutions to its various problems. But here are the ones you can do to address the issues listed above:
- Fix the cone. Depending on the extent of damage your cone has, you may be able to salvage it from complete impairment by doing either of these:
- Glue plus cone material. Using the cone’s material as patches to cover the small tears is one of the most common fixes to the damaged cone problem. Along with either paper, fabric, etc., glue (such as Elmer’s) or epoxy is used to attach the material on to the subwoofer's cone. Others, however, advise using speaker repair glue for better adhesion.
- Measure the size of the cut. Use a ruler or tape measure for accuracy.
- Prepare the patch. Using scissors, cut the paper or fabric just a little bit bigger than the size of the cut. Prepare two for each tear.
- Glue it. Using your chosen adhesive, attach the patch atop the tear and let it dry. Do the same for the opposite side of the cone. Make sure you don’t use too much glue as it can make the foam stiffer.
Although you are going to purchase a re-coning kit, it is still much cheaper than buying a new subwoofer.
- Remove the old cone. Using a cutter or blade, cut the surround of the basket and pull out the entire cone off of it.
- Get rid of glue debris. Using the blade and a rough fabric, scrape off any excess glue from the basket. Make sure nothing goes into the voice coil gap. Cover it with paper or fabric while cleaning the basket.
- Place the new cone. Once you’re sure the frame or basket is clean enough to accommodate the new cone, apply glue to both the frame and the basket using the glue that comes with the kit. Also, apply glue to where the spider will be attached.
- Solder the wires to the terminals. When attaching the new cone to the frame, make sure the terminal wires are facing the terminal ports. Then use a soldering iron and lead to attach each wire to its respective terminals.
- Clean excess chaffs. Using any cloth, dust off any dirt accumulated during the process.
- Check cables and power supply. If the reason your subwoofer stopped working is the lack of power, do the following:
- Turn off subwoofer and all electrical units connected. Because you will be dealing with electricity, it is just proper to turn off all devices before touching any of them.
- Check all the cables. From the subwoofer to the battery, check all the cables attached to them. Know if everything is properly attached to the ports or that there are no damaged cables running through the car. If there is, you may have to replace it.
- Check the amp, power supply, and fuse. The amplifier should be able to handle the subwoofer’s power rating. So check and recheck the specs of each device. If both are OK, check if the car’s battery is charged enough to let electric juice flow through the cables correctly. You may also check the fuse as it may need replacing.
- Test. After doing a thorough inspection of the unit, cables, and power supply, test the subwoofer and see if anything changes. If it still doesn’t work, you may have a blown sub and need to buy a new one.
How to Tell If a Car Subwoofer is Blown
If you’re not sure whether there is a chance to resurrect your subwoofer or not, do these simple tests to find out:
- Press the cone. Using four fingers on each hand, push the both sides of the cone firmly and carefully. A blown subwoofer will either have scratching noises or be unresponsive to your presses. Also, if the cone moves too easily, it may indicate that the spider is starting to wear. It may also lead to blowing your subs.
- Check the resistance. Using a voltmeter, hook up its wires to the positive and negative terminals respectively and check for the resistance. If the number that shows on the voltmeter almost matches the subwoofer’s claimed resistance, you're all good. But if the number is unstable and shows a random level of resistance, say from 4 to 20 then 5 ohms, it is definitely blown.
When a subwoofer is blown, you may simply re-cone it and follow the steps above. But if you want to spare yourself from all the elbow grease, buy a new one instead.
A blown subwoofer may be proof that forever no longer exists. But it doesn’t mean you should turn your back on the bass game just because your subwoofer stopped working.