Why Is My Subwoofer Not Working?

Malfunctioning subwoofers are more common than you think. However, jumping to conclusions and replacing them isn’t the way to go. You might just be throwing out a completely repairable sub!

Asking, why is my subwoofer not working?

Here’s the short answer…

There are a plethora of reasons tied to a subwoofer not working anymore. It can be a very surface-level cause, like forgetting to turn the power switch on. On the flip side, it can be serious, like magnetic field interference. So, the list of sub-fail causes goes on.

But don’t lose hope. We’ve compiled all the most common causes of subwoofer failures along with their solutions. First, let’s assess whether your subwoofer is really working or not.

How to Tell If My Subwoofer Is Not Working

Usually, when subwoofers stop working in vehicles, it’s due to the unit blowing out. This happens because the subwoofer receives too much power or distorted signals.

To tell if your subwoofer is not working, you first have to find out if the sub is blown and then take its ohm rating to ensure if it’s out of order.

How to Tell If a Subwoofer Is Blown

To tell if a car subwoofer is blown, first detach the cone from the unit carefully. Take it in both hands and push down on each side of the cone with your fingers. If you hear any crackling, squeaking, or scratching noises, that’s a sign of a blown subwoofer.

The sub could also be blown if you notice that the cone is not moving down when you push on it. When this happens, it’s said that the sub is “frozen” as the coils inside it fail to function. Regardless, your sub cone should easily give when you push on it, and it should not show difficulty in moving either.

Main Signs of a Blown Subwoofer 

  • No audio output, even when the amplifier is on
  • Unclear sound with fizzing or buzzing noises
  • No sound at all
  • The speakers work, but the subwoofer doesn’t
  • Strange noises (crackling, popping, thumping, etc.) when audio played at high volumes
  • Strange noises coming from the subwoofer

How to Take the Ohm Rating of a Subwoofer?

To do this, turn over your sub to the end, where the positive and negative terminals are located. Use a digital voltmeter and hook up the positive and negative leads to their respective terminals. Check the reading on the voltmeter and see if it matches the advertised ohm rating of your sub.

If the reading shows a difference in resistance of around 0.2 to 0.4 points, it’s nothing to be concerned about. For instance, a 4-ohm sub can give a reading of 3.7 ohms or 3.6 ohms, which is perfectly fine.

When taking the voltmeter reading, you need to look for the jumps in deviation of the points. For example, a reading that jumps between 3 ohms to 7 ohms and then back to 5 ohms is a sign of a blown sub.

Why Is My Subwoofer Suddenly Not Working?

If you have come to the conclusion that your car’s subwoofer is not working and is probably blown, there are a couple of reasons this issue leads to from–

1. Improper Connection

Like with all electrical appliances, an improper connection leads to the device not working anymore. This can easily be solved by simply unplugging the subwoofer and plugging it back in. Alternatively, you can switch the input from AUX to SUBWOOFER on the amplifier.

2. Blown Fuse

The circuit which powers your subwoofer might have gone dead. In this case, you should check your sub’s fuse to see if it’s blown. If it has, replacing it should solve the issue.

3. Broken Cone Seal

In order to produce sound, the subwoofer cone needs air to push against and move. Sound is produced by the cone pushing and pulling the air, which can only be done if the cone is mobile.

The cone is joined to the subwoofer with a seal that prevents air from moving over the enclosure. If the seal breaks, the movement of air is interrupted, and the subwoofer eventually malfunctions.

When the malfunction occurs, the air moves over the enclosure and other places within the sub, which causes it to interfere with the unit’s resistance. This can be visibly evident by the cone moving back and forth too frequently.

4. Driver Magnet Issue

The cone of a subwoofer is connected to a permanent driver magnet. This is a very important component of a subwoofer, as these magnets create a magnetic field that makes vibrations that turn into the sounds we hear.

Through audio signals, voltage and current travel along the circuit of the electromagnet with the permanent driver magnet, which moves the cone. This physically produces and amplifies sound.

When the permanent driver magnet fails, it stops working with the electromagnet by changing the number of magnetic poles in the circuit. As a result, the subwoofer does not produce any audio.

5. Other Magnet Problems

There are other magnets within the subwoofer that are not just permanent driver magnets. As there is a magnet in the circuit, if there’s also another magnet close to it, the magnetic field is interrupted, and the forces change.

This causes the audio signals to fluctuate, which eventually leads to heavily distorted sound output.

6. Short Circuits

The most common subwoofer fails are tied to short circuits. These accidents are sudden and usually unprovoked, which is why even brand-new subs might fail as well.

Short circuits occur when there is an imbalance in the resistance of a circuit resulting from the diversion of a current. If you sense a short circuit, you can try to save your subwoofer from blowing by checking its terminals.

However, short circuits can do more damage than just a blown sub. They can lead to an interruption in the electromagnetic field, which will distort the sound. Plus, they also impact the cone’s movement and prevent it from producing sound.

7. Low Power

Amperage is highly important when it comes to powering a subwoofer. If your sub is not getting the proper level of amperage it needs to transmit stable audio signals, it can result in internal damage and strange noises.

Be sure to check the coil of your sub or do an amp check to be cautious of power deprivation.

8. Protect Mode

In case something goes wrong, your subwoofer comes with a protection mode that alerts you when an issue is at hand. When there’s a problem, the unit will have flickering lights which warn you about sub-issues, speaker inconsistencies, connection troubles, and much more.

An important feature of the protect mode is that it turns off your subwoofer temporarily to prevent further damage that these issues may cause. As a result, you may feel that your sub stopped working suddenly.

Furthermore, in order to get out of protect mode safely, you’ll need to solve the issue completely and make sure the sub is safe to run normally.

How to Fix a Subwoofer That Is Not Working

Since a malfunctioning subwoofer can be linked to many issues, you can try several troubleshooting methods before you consider a replacement.

In no particular order, here are all the possible ways you can fix a sub that is not working:

Fixing Input Connections

If your sub is not working even though the amp has power, chances are that it has to do with input issues. So, start by checking the input connections on your sub to confirm if the system is connected to a power source.

While checking, make sure to assess the cables and wires for any visible damage and installation issues. Also, check the main stereo system, as input connections are also located there.

You can also try unplugging and plugging each of the cables and/or wires. If you find damaged or old cables, it’s best to have them replaced to avoid electrical hazards.

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Assessing Outlets

When a sub is powered, it has a LED which turns on, typically during standby mode. If this LED is not glowing, there is a connectivity issue. This means that the unit is not directly connected to the power source.

Check the power outlets at all points that your sub might be getting power from. It only takes one failed connection to turn off the entire system, so be careful about this. If you think that one of the outlets is causing an issue, make sure to plug the unit into a different outlet.

Fixing the Wiring

Wires and cables are responsible for transmitting audio signals and electrical activity through the stereo system. Damaged or worn wires/cables can lead to subwoofer issues.

Anything from bunched-up wires, rips, rust, and loose connections to fuses, can cause wiring issues that lead to sub-failure. Fortunately, these wires can be replaced easily.

Checking the Speakers

Since the stereo system is a number of units working together, it’s important to consider each and every one of them when fixing a specific problem. In the case of sub failures, you should always check the speakers before attempting to replace or repair the subwoofers.

Test to see if the speakers work fine on their own. If they do, there is a problem with another system unit. And if they do not, then the cause of the issue is the speakers.

Toggling System Settings

If you have confirmed that there are no issues with the cables and wiring, you can move on to checking the system settings. Check both your amplifier and receiver to see if the settings for them are still at the levels you first set them on. Also, check the input audio and output levels on your subwoofer.

In case any of your systems units have specific settings according to their speaker’s size, you should also consider them. Work your way up the settings from smallest to biggest until you find the suitable size. A size that’s set to a higher setting might block audio signals for your subwoofer.

However, some receivers can handle higher size settings; you just need to check the user manual to make sure which settings are safe to use.

Turn the Volume Up

There may be a problem with the volume levels of your unit. The speakers or subwoofer can have volume levels turned all the way down or put on mute. This can be solved easily by turning the volume up.

Other than these two components, check the volume levels for your amplifier and base unit to ensure the volume matches the other units. Test the system at intervals when increasing the volume, don’t max out the volume levels and risk damaging the system.

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Frequently Asked Questions

1. My subwoofer suddenly stopped working; what do I do?

First, you should check if there was a blown fuse. If there was, you should replace it immediately and test the system with a different power outlet just to be safe. 

2. What is the most common reason for subwoofers not working?

The most common cause for a failed subwoofer is poor connectivity. Wiring issues such as twists, rips, tears, knots, rust, and more are dangerous for the entire stereo system, especially subwoofers. This is because the poor connectivity within these problematic wires interrupts the electricity transmission within the sub.

3. How to fix the subwoofer not working even when the amp has power?

Start by toggling the switch settings and making sure it is set to ‘Master’ and not ‘Slave.’ Then, check cables to make sure there are no connectivity issues, and repair any faulty connections. Moreover, make sure there are no problems with your vehicle’s battery, as this could affect the power supply to your stereo system.

4. Can subwoofers go out of order/bad?

Many subwoofers can last from 5 to over 14 years on average. However, poor maintenance will hasten the rate of aging and lead to the sub “going bad.” You should clean and replace old wires on a regular basis to avoid this. 

5. What does a failed subwoofer sound like?

The concerning sounds a failed subwoofer can make are crackling, popping, thumping, buzzing, fizzing, and scratching sounds.


To answer ‘Why is my subwoofer not working?’ simply, it can be due to a number of reasons, ranging from a simple issue such as not powering on the unit or a bigger cause such as a broken sub cone.

Fortunately, most of the common causes for failed subs can be dealt with at home, as detailed in our How to Fix section. However, we still recommend consulting experts when handling electrical issues such as wiring.

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