Subwoofer Making Noise When Turned On/Plugged In

14 Reasons: Why is Subwoofer Making Noise When Turned On or Plugged-in

There could be many potential reasons that can cause the subwoofer to make a loud humming noise when your turn on your home or car audio system:

1. Ground Loop:

The lousy ground is an electrical situation that can cause interference when two elements in a system are connected using an earth ground. This connection can create a current loop, allowing AC noise to travel into the subwoofer, resulting in an audible ground loop subwoofer hum or buzz from the subwoofer when turned on.

2. Electrical Device Interference:

Electrical interference from your other devices, such as cell phones, laptops, or even routers, can cause a sub to make a noise when turned on after connecting with or keeping these devices closer to the sub. This results from an electrical current from the other device, which causes the electromagnetic interference signals with the subwoofer’s sound and creates a humming or buzzing sound.

3. Power Supply Issues:

A bad electric output, power cord, or damaged power supply can cause your subwoofer to make an unpleasant noise when you start your stereo system. Furthermore, you may also face such a sound if you’re providing an insufficient power supply.

4. Damaged Subwoofer Component:

It consists of a subwoofer motor, voice coil, speaker cone, and magnet. If any component goes wrong, your sub will produce a crackling, rattling, or humming noise. You can check for any tear sign on your subwoofer by a visual inspection.

5. Amp’s Internal Failure:

As I have already mentioned, you may hear the subwoofer noise when you power the amplifier. This is because your amplifier needs some time to warm up properly before it provides full power to your subwoofer. You should wait a bit without worrying. However, if the sound keeps going, it may be due to the amplifier’s internal failure, such as transistors, capacitors, or any integrated component.

6. Poor-Quality or Damaged Output Jack:

When the amplifier’s output jack of a sub is poor quality or damaged, it can cause your subwoofer to produce an unbearable sound when it starts. The damaged area creates an audible vibration when an electrical current flows through it, resulting in loud annoying sound waves.

7. Overdriven Subwoofer:

When you connect your subwoofer to an amplifier that can provide more power to the subwoofer than it needs, it can cause it to produce an unpleasantly loud noise. And this usually happens when you turn on the volume on a high level for an extended period. If not taken any action, it can permanently damage your car sub.

8. Placing Subwoofer Close to Wall:

When you move your subwoofer to the wall, you may hear a change in your sound output. It can create reverberations that cause low-frequency sound waves to reflect off the wall and return toward the subwoofer, making standing waves within the room. Furthermore, it causes bass output to resonate at louder levels than normal.

9. Setting Crossover Too High or Too Low:

When you set the crossover too low (without any knowledge), all of the frequencies are sent to the subwoofer, causing it to overload and make a loud, buzzing noise when powered on. If you set it too high, not enough bass frequencies will be sent to the subwoofer, resulting in poor performance and distortion. In both cases, you’ll hear an awful noise.

10. Damaged or Cracked Voice:

As mentioned above, when a voice coil is damaged or cracked, it can cause the subwoofer to produce excessive noise when turned on. This noise usually comes from the air being pushed through the damaged coils and is caused by vibrations that travel up and down through them.

11. Using Wrong AC Power Outlet Switch:

When you power your home stereo system through a bad AC power outlet switch (power strip included), it will make a loud noise when you turn it on. In my experience, this happened because the switch wasn’t correctly connected to the circuit and caused too much current to flow through, resulting in an audible buzz or subwoofer hum.

12. Low-Quality Speaker Terminals:

Low-quality speaker terminals lack the proper insulation and shielding to protect against electrical surges, resulting in a humming or buzzing sound. This is especially common with low-end models unsuitable for higher power levels.

13. Poor Construction:

Poor connection or construction of a subwoofer can cause it to produce an undesirable noise when turned on. This usually happens to faulty connections between the subwoofer and amplifier, such as mismatched RCA connectors. Other problems may include loose connections between wires, exposed wires touching each other, or improper system grounding.

14. Amplifier Clipping:

When a subwoofer’s amplifier is pushed too hard and causes clipping, it can cause subwoofer noise when turned on. The excess power distorts the audio, creating a high-pitched squealing sound. The only way to avoid this is by setting the gain correctly for each of your subs and adjusting your amp settings to match.

12 Steps to Avoid Subwoofer Noise When Turned On:

Now that we know the reasons let’s take first-aid steps to prevent the awful sound when plugged in:

1. Check All Connections:

Take my example! When I get myself into trouble, I ensure the connections are in good shape before checking further. To prevent a subwoofer from making noise when you turn it on, ensure all the connections between the subwoofer and the audio source are secure. This means checking that all cords are firmly connected to their appropriate ports and verifying that nothing is loose or damaged to eliminate the subwoofer making static noise.

2. Use High-Quality Audio Cables:

High-quality audio cables, such as RCAs, to connect a subwoofer can help reduce or completely prevent the noise. Low-quality cables may lead to unwanted electrical interferences, resulting in the audible buzzing and humming sounds.

3. Adjust Crossover Settings:

Adjusting the crossover settings can be very helpful in preventing the subwoofer from making unpleasant sound waves. This involves changing the frequency setting for subwoofers to ensure that only specific frequencies are heard, avoiding any unwanted noise from them. You should also ensure stable HPF and LPF settings on your head unit.

4. Use Ground Loop Isolator:

A ground isolator can help prevent noise from a subwoofer by breaking the connection between two different grounds. This breaks any possible loops caused by the signals from various sources and helps reduce or eliminate unwanted noise. It filters out electrical interference, providing consistent sound across all components.

5. Keep Subwoofer Away From Other Electrical Devices:

You should keep your subwoofer away from electrical devices such as cell phones, laptops, or even fridges. This is because the subwoofer emits sound waves, which can interfere with signals generated by electronic systems, causing a disturbance. Ensuring there is no interference between your subwoofer and other electronic devices will help prevent unwanted noise when turning on the device.

6. Check and Replace Your Audio Jack Cable (If It’s the Reason):

As mentioned above, if the cable is faulty or old, it might disrupt the signal between the amplifier and subwoofer, resulting in noise. Replacing the audio jack cable with a new one that meets industry standards can help restore a good connection and prevent unwanted noises.

7. Switch Outlets:

That’s a quick remedy you can perform to see if the noise has been eliminated or not. Switching outlets (power strip included) can help prevent noise from coming from your subwoofer. You should disconnect it from the current wall outlet and plug it into another. This often stops excess noise caused by ground loops or power supply issues in the previous one.

8. Make a Proper Ground Connection:

For car audiophiles! Proper grounding involves connecting a wiring or a grounding strap between the ground point of your amplifier and a good electrical ground. This will ensure that any built-up static electricity or stray current in your system gets discharged, preventing unwanted noise from being produced.

9. Check Subwoofer Components:

As we know, a defective sub can cause your such trouble. You must visually inspect and look for the subwoofer’s components that have been damaged or blown away, especially the voice coil. For example, you should replace the voice coil if you see any signs of a blow.

10. Use a Noise Filter:

It helps by restricting any DC that passes through the subwoofer and suppressing any high-frequency signals/noise present in the audio signal. This, in turn, reduces power intake and keeps the sound clean, preventing any unwanted low subwoofer hum or hissing noises caused by subwoofers being turned on. You can also use a device audio isolation transformer.

11. Separate the Audio Cables:

Separating the cables can eliminate interference, such as hums or buzzes. Additionally, physically separating audio cable strands or using shielded cables will help reduce crosstalk between connected audio devices which can also lead to undesired feedback and noise.

12. Just Upgrade Your Subwoofer:

If you have tried all the above steps but in vain, you must upgrade your subwoofer with a new one. I know that’s not the way you’re looking. But I must say, your subwoofer may have blown permanently. Before choosing a new subwoofer, adjust the ohm with the amplifier.