Subwoofer Pulsing With No Sound: Causes, Solutions

Last updated on June 23rd, 2022 at 12:04 am

You’re sitting down to watch your favorite movie, but as soon as the opening credits start you hear a loud pulsing noise from your subwoofer and there is no sound.

But, it’s not coming from the TV speakers- it’s coming from your subwoofer. And even when you turn the volume all the way down, the pulsing noise is still there.

Or, you don’t hear any sound, but you might hear the pulsing.

What’s causing your subwoofer to pulse with no sound, and how can you fix it?

A subwoofer may be pulsing with no sound due to a bad media device, faulty amplifier/AV receiver, Incorrect frequency setting, poor grounding, inadequate power supply, damaged fuse, source of interference, or bad cables.

In this article, you will know the causes of your subwoofer pulsing with no sound and the solutions for that.

Reasons for subwoofer pulsing with no sound

Let’s know about the causes of Subwoofer pulsing with no sound and their solutions.

1. Bad media device

One of the most common causes of this problem is a faulty media device. If your subwoofer is connected to a media device such as a TV, Blu-ray player, computer, or stereo receiver, and it’s not working correctly, the problem is most likely with the media device.

When a media device is not working correctly, it can cause all sorts of audio problems, including a subwoofer pulsing with no sound.

This may happen due to an issue with the audio driver and other problems with the media device.

Solution

You can solve this problem by updating the audio driver. You can also try reducing the volume down to zero. But, the problem is you can’t fix the “No sound” issue by doing that.

2. Faulty AV Receiver

If you’re using an AV receiver or stereo receiver to connect your subwoofer, and the subwoofer is pulsing with no sound, the problem may be with the AV Receiver.

An AV Receiver is a device that connects all of the audio and video components in a home theater system. It also switches between the different input sources, such as a Blu-ray player, TV, or game console. So, we can say that it’s the core part of the home theater system.

If the AV receiver is not working correctly, it can cause the pulsing with no sound.

Solution

You can try restarting the AV receiver. If that doesn’t work, you should check the owner’s manual for troubleshooting steps. You can also try unplugging the power cord from the AV receiver and plugging it back in.

3. Bad amplifier

Another cause might be a defective or bad amplifier. An amplifier is a device that increases the strength of the signal. It’s used in audio systems to increase the volume.

If the amplifier is defective, it can’t transmit the signal correctly. So, you may have the “pulsing with no sound” issue.

However, if you are having this issue with the car subwoofer and amp, you should check if the amp is shutting down on its own. It may occur when the volume is too high.

Solution

If you think the amplifier is the problem, you should take it to a professional to have it checked and repaired.

If it’s not repairable, you need the replace the amplifier.

4. Incorrect frequency setting

If you are using an audio receiver, make sure that the crossover frequency is set correctly. The default setting is usually 80 Hz. If you set it too high, the subwoofer will be deprived of low-frequency sounds.

As a result, the subwoofer will work harder to produce those frequencies, which will cause a pulsing sound.

Your subwoofer may be pulsating when you pay a move at a low volume due to the bass getting too extremely loud and strong.

Solution

To fix this, set the crossover frequency to the lowest possible setting. If you are using a soundbar, the crossover frequency is usually set automatically.

To solve the issue with the movie I described above, first, turn the volume up and then reduce the volume again until you hear the bass and there’s no pulsating.

5. Incorrect phase setting

If the subwoofer is out of phase with the other speakers, it can cause a pulsing sound. This happens because the subwoofer is trying to reproduce the same frequencies as the other speakers.

Solution

To fix this, set the phase to 0 degrees.

6. Low pass frequencies

A low-pass filter is an electronic filter that allows low-frequency signals to pass through while attenuating (damping) signals with frequencies greater than the cutoff frequency. The exact frequency response of a low-pass filter relies on the design of the filter.

Sometimes, If you turn the LPF down, the subwoofer will be deprived of high-frequency sounds. As a result, the subwoofer will work harder to produce those frequencies, which will cause a pulsing sound.

Solution

To fix this, set the LPF to the highest possible setting. Adjust the amplifier’s gain and bass management options correctly.

7. Insufficient power supply

The subwoofer requires a certain amount of power to function properly. When the power supply is insufficient, the subwoofer may not be able to generate enough power to produce sound. This can lead to the subwoofer making a pulsing or heart-beating.

Solution

The solution is to provide the subwoofer with a sufficient power supply. Make sure that the power outlet you are using is providing enough power for the subwoofer to function properly. You may also need to use a different power outlet or use a different power source altogether.

8. Bad grounding

Another potential cause is bad grounding. The subwoofer needs a good ground in order to function properly. If the ground is bad, it can cause the subwoofer to pulse.

The subwoofer amplifies the audio signal that is sent to it. This amplified signal is then sent to the speakers. The speakers convert this amplified signal into sound waves.

The subwoofer also has a ground wire. The ground wire is used to complete the circuit. Without the ground wire, the circuit is incomplete and the subwoofer will not be able to function.

If the ground is poor, the current passes through the ground wire rather than through the subwoofer. This can cause the voltage to fluctuate which will cause the subwoofer to pulse.

Solution

The solution to this problem is to make sure that the ground is good. If not, go guiding properly.

There are a few ways that you can ground your subwoofer. One way is to use a grounding block. This is a small device that you can connect to the subwoofer and then to the ground.

Another way is to use a grounding wire. This is a small wire that you can connect to the subwoofer and then to the ground.

You can also use a grounding strap, mat, plate, or rod.

9. Bad fuse

A bad fuse can cause this pulsing subwoofer.  Fuses provide protection to the circuitry by breaking the circuit when there is an excessive current.

This excessive current can be caused by a short circuit or an overload. If the fuse is bad, it will not be able to provide this protection and as a result, the current will flow through the circuit unchecked which can cause damage to the components.

When the current passing through the circuit unchecked, it can cause the voltage to fluctuate. This fluctuation in voltage will cause the subwoofer to pulse.

Solution

The solution to this problem is to replace the fuse with a new one.

10. Defective component

Another potential cause is a defective component. The subwoofer has several components that are necessary for it to function properly. If one of these components is defective, it can cause the subwoofer to pulse.

Solution

The solution to this problem is to replace the defective component.

11. Source of interference

Another cause might be the Source of Interference.

The source of interference can be any device or appliance that emits electromagnetic fields. These devices can include microwave ovens, baby monitors, WiFi routers, Bluetooth devices, and even cell phones.

Interference can cause Subwoofer pulsing by disrupting the electromagnetic fields that are responsible for producing sound. When these fields are disrupted, the sound waves are no longer able to travel in a straight line, which causes them to reflect off of objects and create a pulsing noise.

Solution

There are a few things you can do to reduce or eliminate interference-caused Subwoofer pulsing:

1. Move the source of interference away from the Subwoofer.

2. Use a different frequency range for the Subwoofer.

3. Use a wireless subwoofer instead of a wired one.

4. Place the Subwoofer in a different room.

5. Use soundproofing materials to block the interference.

12. Defective capacitor

Another reason is a defective capacitor. A capacitor is an electronic component that can store and release electric energy.

It is present in almost all electronic devices including subwoofers.

A capacitor consists of two metal plates separated by an insulating material known as a dielectric.

The function of a capacitor is to store electric charges.

When a capacitor is defective, it can cause the subwoofer to pulse or make a heart-beating.

The reason for this is that the capacitor is not able to store or release electric charges properly.

Solution

The only way to fix a defective capacitor is to replace it.

You can either do this yourself or take the subwoofer to a professional for repair.

13. Bad cables or poor wirings

A cable may be worn out due to age or may be of poor quality. The cables that connect the subwoofer to the power source or amplifier can also become loose or damaged over time.

This can cause the subwoofer to pulse or make a heart-beating.

Check out my other article on RCA cables for subwoofers.

Solution

The best way to fix this problem is to check the cables and wirings. If you see that any of the cables are loose, tighten them. If the cables are damaged, you will need to replace them.

14. Faulty subwoofer

Finally, if the subwoofer is faulty or too old, it can cause the subwoofer to pulse with no sound.

Solution

If you have a defective subwoofer or an old one, it’s better to get a new one to get rid of the pulsing issue.

Troubleshooting subwoofer pulsing with no sound

Here is the step-by-step guide.

1.  Check the media device.

If your subwoofer is pulsing with no sound, the first thing you should check is the media device that you are using. It could be a faulty DVD player, Blu-ray player, or another type of media device.

If you’re having this problem, the first thing you should do is check the connections between your subwoofer and the media device. Make sure the cables are plugged in correctly and firmly.

If that doesn’t work, try disconnecting and reconnecting the cables. If that still doesn’t work, there is a problem with the media device.

And, if the media device is not working properly, it can cause the subwoofer to pulse with no sound.

2. Check the amplifier/AV receiver.

If the media device isn’t the issue, the amplifier or AV receiver should be checked next. The subwoofer may pulse with no sound if the amplifier or AV receiver is not functioning properly.

3. Check the frequency setting.

If the amplifier or AV receiver is not the issue, the next thing you should check is the frequency setting. The subwoofer may pulse with no sound if it is not set to the correct frequency.

Check out why your subwoofer isn’t as loud as used to be.

4. Check the grounding.

If the frequency setting is not the issue, the next thing you should check is the grounding.

The best way to do this is to use a multimeter. Set the multimeter to the ohmmeter function and place the probes on either side of the ground wire. If you can’t do it on your own, contact a professional if you can’t.

5. Check the power supply.

If the grounding is not the problem, the power supply should be checked next. If the subwoofer does not receive enough power, it may pulse without making any sound.

6. Check the fuse.

If the power supply is not the issue, the next you should check is the fuse. The subwoofer may pulse with no sound if the fuse is blown.

The easiest way to check if the fuse is bad is to use a multimeter. Set the multimeter to the ohmmeter function and place the probes on either side of the fuse. If you can’t do it on your own, hire a professional.

7. Check for interference.

If the fuse isn’t the problem, the next step is to look for interference. If there is something interfering with the transmission, the subwoofer may pulse without sound.

8. Check the cables.

If the interference is not the issue, the next thing you should check is the cables. The subwoofer may pulse with no sound if the cables are damaged or not connected properly.

Also, check out my other article about subwoofers making a rumbling noise.

Conclusion

There are a few different reasons why your subwoofer may pulse with no sound. The most common causes are a faulty media device, bad amplifier/receiver’s incorrect frequency setting, bad grounding, and defective components of the subwoofer. If you troubleshoot the problem and still can’t find the solution, you should contact a professional for help.

However, if you can find the cause of the issue, you can simply fix it on your own, and if it’s due to a defective component, you need to replace that.