Noise in your audio system can come in three forms. Whining noise from speakers, car speakers buzzing off, and radio static. The tricky part is to determine the source of the noise as it can come from different sources. Here are issues behind speakers making noise when the car is off.
Why Speakers Make Noise When Car is Off?
The following are possible causes why your speakers are making noise despite the engine is off.
Electrical Interference
Anything that can distort or transmit signals like phones, power cables, or a plugged-in USB port can cause electrical interference. A problem may arise from something simple: leaving a mobile phone at the armhole near a speaker or as a result of some other power source that runs close to your speaker wiring. Electrical interference is often an issue with stereo systems fitted with an aftermarket amplifier.
If you have an amp installed, ensure the RCA cables that run from the amplifier to your head unit are not lying near the amplifier’s power wire. To fix the issue, you need to move either the RCA cables or power wires apart.
Poor Grounding of Stereo Equipment
Each stereo component needs grounding, including the head unit, amplifier, equalizer, and other installed components. Grounding involves attaching a wire from the element to a bare metal bolt connected to the chassis. The ground wire should connect firmly, fix to a bare unpainted surface, and be as short as possible.
The grounding wire should also be thick as the wire that supplies power to the component. Ensure you check all the connections and consider installing a thicker wire if need be.
Stereo Receiving Power When Car is Off
You can try this with your engine off and keys removed, and turn the radio on. If the radio can switch on and play, your stereo system is receiving power from the battery. The random noise from the speaker can be a problem. You can fix it by switching off the radio before turning off your car.
Antenna Lead Noise
Check out and see if you are getting noise on all sources like playing CD, auxiliary /USB, AM, and FM. If the noise is there only on the radio, it’s mostly coming through the antenna lead. Try unplug the antenna. If the noise goes away, install an antenna noise suppressor. The filter plugs-in- the line between your receiver and your antenna breaking the ground path between them, thus preventing noise from entering your system.
Radiated Noise
If the noise isn’t from the antenna, try pulling the receiver from the dash while a CD is playing. If the noise isn’t present, the source is from your system due to the receiver’s proximity to a noise producer. The noise is known as sideways noise.
If the noise-causing accessory has a motor, you can install a noise filter on accessories power to minimize it. If the car computer is the issue, move the receiver’s wiring away from the accessory. You can use
Engine Noise or Alternator Whine
The noise comes through the power and ground wires connected to your receiver. The engine noise causes whining or clicking sound. Its pitch varies with engine speed.
To fix it, you can install an alternator noise filter on the battery and alternator’s power line to reduce the noise. Again, you can install a noise filter on the receiver’s power to cut down signal interference.
Noise in Patch Cables
RCA patch cables can pick noise as they connect to your components. To test this, detach the wires from your amp. Insert one side of a spare patch cable into amps left and right input jacks and turn on your system and engine. If there is no noise, reconnect the wires to the amp and disconnect them from the receiver. In case of any noise, your patch cables are the problem.
Ensure you separate them at least 18 inches from the power cables. Consider purchasing a better brand of patch cables with good insulation. The size of the cable loop may also affect the noise produced.
If the loop area is large, the patch cable will be more vulnerable to noise. Please purchase a thread with a twisted pair design as a smaller loop area has less noise. Another option is installing a ground loop isolator between the receiver’s preamp output and your amp.
Noise in Speaker Wiring
If your speaker wires are of inferior quality or did the wiring poorly, the car radio may still receive power. Static noises may come from incorrectly wired speakers.
New Amplifier
An amplifier can cause noise into your system through the lousy ground or incorrect mounting. Rubber grommets or feet may help isolate the amplifier from the vehicle’s chassis, a potential noise source: you may consider installing a noise suppressor.
Check this too: Best 6×9 Car Speakers
Types of Noises Car Speakers Make
The following are noises made when the car engine is off;
- Static/ white noise can be from the speaker’s electrical system due to poorly patched cables or wiring.
- Clicking/whining sound: the noise can be due to low or ground wires connected to the receiver. The sound varies with the engine’s speed.
- Hissing sound: may be due to the electrical system.
Why Do My Speakers Pop When I Turn My Car Off?
A break in the circuit or loose connection will cause the system to pop, resulting in an irritating noise and danger to your speaker’s shelf life. The popping is a surge of electrical current jumping over a broken wire connection or a rise in the amplifier’s output settings.
How to Fix the Problem
- Locate the origin of the popping noises.
- Determine which speaker or speaker wires, amp, or equalizer has issues
- Adjust the amplifier and equalizer. If the noise is from one speaker only, adjust the amp, and if from many speakers, change the equalizer and amp settings—In case of any defects, you need to repair the components.
- If the tips above fail, try connecting a different speaker to check if the issues are in your speaker. When none of the above tips works, consider seeking professional help.
Why is there a Whining Sound from my Speakers When Accelerating?
It’s an engine noise that occurs most likely due to electrical interference from the alternator output. The noise from the alternator gets into your head unit through the power cables. You can fix the issue through the following;
- Fix a noise filter between the battery and alternator
- Install an inline noise filter in the head unit power cable
The tips will help prevent the noise from getting into your head unit and causing the speaker to whine.
Conclusion
The easiest way to avoid speaker issues when the car is off is by seeking professional services in installing your system. Again, ensure you invest in quality speakers, wiring system to avoid all sorts of interference. It may be costly, but it will save you a lot of money. The investment will silence a subwoofer that vibrates when the car is off.
