An appropriately vibrating subwoofer provides you with a sound and satisfying listening experience. It is a crucial component of your car’s stereo unit to increase the audio experience. But, there are some times for you when you realize the subwoofer is vibrating even if the car is parked.
So, why the subwoofer vibrates when car is off? The prominent reasons for such an attitude of the subwoofer are issues with RCA cables, grounding problems, loose connection, the orientation of electrical interference, and loose suspension. Also, sometimes loosely set up on the base, inappropriate base frequency, etc., can cause the issue.
Here, in this article, we discuss these causes and their solutions in a detailed manner. Let’s check these out.
Subwoofer Vibrates when Car is Off – Causes And Solutions
We have already informed you of the causes and solutions if your car’s subwoofer vibrates when its engine is off. Here, we elaborate on those.
Issues with RCA Cable
The connection between the subwoofer and your car’s AV receiver or amplifier is established by an RCA cable set. This cable is designated to transfer the bass signals from the source, like an AV receiver or amplifier, to the subwoofer.
A faulty RCA cable set or poor installation hosts an electrical issue named Ground Loop Hum. This looping issue makes the subwoofer vibrate while the car is off. To elaborate, ground loop hum orients when more than one conductive path is created by the cabling system.
One path creates a 120 Hz buzz and another 60 Hz buzz. Here, one path hosts the electric current to move from one unit’s ground to another unit, and the second path hosts the return of the current to the initial unit.
Following this, even if your car is off, the created circuit passes signals to the subwoofer, making it vibrate.
How to Solve
Below is the step wise guideline to solve the RCA cable issue.
Step 1
Check whether the installation is proper or not, as per the color code combination. If it is proper, then you need not change the RCA cable; remain with the existing color code setting.
Step 2
Purchase a well-shielded and low-noise RCA cable set.
Step 3
Install the cables by following the color codes of the source and subwoofer’s ports. The subwoofer won’t vibrate anymore if it is not on.
Grounding Problem
If the subwoofer’s grounding cable is below 18 gauge or bad, it creates an imbalance within the current flow-through. In this case, even if you switch off the engine, the grounding wire hosts some electricity flow, creating an alternate current-flow path.
This current flow makes the subwoofer vibrate, though there is no power.
How to Solve
The following is the step-by-step guide to solving the grounding issue.
Step 1
Check both ends’ connections for the grounding. Also, ensure that the grounding cable is not touching other parts.
Step 2
Check the cable gauge and condition. The cable must be above 18 gauge, and there is no exposed portion. Upon finding a degraded cable or unshielded portion, purchase a new grounding wire.
Step 3
Remove the old wire and install the new one.
Loose Connection
The faulty cable connection between the input and output can also cause a vibration issue, even if there is no power. A bad connection does not fully release the transmitted sound waves but allows some retention.
So, even after you switch off the car, the retained sound waves hit the cone mechanism of the subwoofer. And this happening results in vibrating the subwoofer at power-off status.
How to Solve
Here is the practical process to solve the loose connection issue.
Step 1
Ensure all the wires are properly connected.
Step 2
Check the grounding solution of the sound system’s power supply. If the connection is improper, fix that.
Step 3
The above two approaches are sufficient enough to stop the vibration issue. However, we suggest you install a filter capacitor.
Loose Suspension
To get more bass, many car owners install the subwoofer system on a loose-suspension platform. In such a case, after you switch off the and leave the car by closing the door, the inside air circulation can result in vibration.
How to Solve
In this case, the solution is simple. Just install the subwoofer on a more solid platform that generates less suspension.
Electrical Interference Issue
Electrical interference happens when something wrong is there, like no-shielded wire, other electronic gadgets are close by, etc. This causes an imbalance in the passing of electrical signals in your car’s wires by creating their own electrical fields.
This interference can make your car’s subwoofer vibrate when the car is off because the electrical flow gets unbalanced or wobbly.
Also, if you put the power wire and speaker wires too close together under your car’s carpet, there is a probability of orientation of electrical interference. The reason is that two electric-magnetic fields are created.
How to Solve
Below is the resolution process to get rid of the electric interference issue.
Step 1
The first thing you have to do is to check all the cables, ensuring those are properly shielded. Also, if there is any other electric device nearby, remove that one after switching off the car.
Step 2
Separate all the power and sound-related cables. And clamp those separately with the floor, under the carpet. Ensure maintaining a proper distance between the two types of cables.
Step 3
Now, check the audio system’s main grounding connection. Check whether it is properly fixed or not. Ensure that no current is flowing back to the battery.
Step 4
Switch off the car and leave it. There will be no vibration of the subwoofer.
However, if the reasons mentioned above are not making the vibration, follow the approaches mentioned below.
The Processes to Stop Subwoofer Vibration
If the above reasons are not responsible for the vibration, go for the solutions below.
- You can add an automotive sound dampener
- Check every nut and bolt of its setting with the base. If you find any loose ones, do proper tightening.
- Check the set-up of the bass frequency. Sometimes, a certain frequency can trigger the unusual vibration of the subwoofer unit.
- Go to a workshop if every approach and effort fails. Professional assistance will surely resolve this.
Final Words
We hope that you have a clear understanding of why the subwoofer vibrates when the car is off. By applying the given resolutions, you can easily solve the issue. We suggest you prioritize the grounding and electric interference issue on top of all the mentioned issues.
Finally, you must ensure that the subwoofer grounding cable gauge ranges within 18-20 rm. Also, it is essential to ensure that there is no other high-frequency electric device nearby.
Leave a Reply