Car Amp Turns On But No Sound From Subwoofer

The primary role of a car amplifier is to deliver power for subwoofers to generate bass and improve sound quality. 

Unfortunately, sometimes your car amplifier turns on, but no sound from the subwoofer. What are the causes? And how to solve this problem? 

We will explain the error your car’s audio system is suffering in detail. You can also learn some tips to check your amp. Let’s join us!  

Why Is There No Sound From The Subwoofer? 

The three leading causes for this problem are damaged subwoofers, incorrect wiring or connection, and lack of power supply. We will discuss each in detail and recommend some solutions. 

Damaged subwoofers

The most frequent issue with your subwoofers is shorted subs. An abrupt short may result from metallic contact between the negative and positive polarities at the cone and terminal. 

Try to test your subwoofers with different amps. If it’s completely silent, the cables have got burnt at that point, allowing an electrical signal to move to your sub.

Connection between the speakers and amps 

The connection may be wrong if the car amp turns on but no sound from subwoofer. So make sure you have the amps and speakers connected properly.

You should check if you have linked the power cables from your subwoofers to your amplifier correctly. Often, we use RCA cables to connect the amps through the speaker output. Ensure you link the left and right speakers to their corresponding left and correct wires. 

Also, every speaker’s positive and negative terminals must go into the correct polarity of the amp. 

Read more:

Connection between the amp and head unit 

You can experience issues with the head unit’s output and input cables. The right process starts with the cables between the amp and head unit, then the RCA cables that link the head unit to the amplifier. 

Those input cables, output cables, and RCA wires transfer your audio signal to your amp. The amp won’t work if you plug it in the wrong positions. Hence, the subwoofer won’t produce sound. 

All the components must be properly connected to avoid the situation where car amp turn on but no sound from subwoofer

Faulty wires

One of the issues that might result in your sound signal fading from your subwoofer is faulty wires, particularly the power wires. The degradation and corrosion of such wires may impact the electric current, preventing the sound system from working smoothly. 

Inadequate wiring is another concern, which results in part of the energy required to send power through the wires being turned to heat. The cables may burn out as a consequence.

You often work with four main types of wires in a car audio system

  • Remote wire: The remote wire is vital because subwoofers can’t take the output and produce sound if the remote is off. 
  • Power wire: Once the power wire gets damaged or shorted because of insufficient current, it ceases the whole audio system. 
  • Ground wire: Beginners may misconnect the ground wire, leaving a bad connection between components in the system. 
  • Power antenna wire: This wire is the blue wire found in the back of the amp and used for factory amp turn on.

These wires are important in all car stereo systems. So ensure that you have them properly connected. 

Handle the wire correctly

Lack of power 

Your amp turns on even without obtaining the required operating voltage. However, the subs won’t make any sound since the amp fails to amplify the audio signals and deliver adequate voltage to the subs. 

Using a voltmeter, you can tell whether the voltage is from 12 to 14. If the reading is lower than 12, check for loose connections in the battery, grounding bolts, and fuse blocks. 

Moreover, keep in mind that some amps come with built-in fuse switches. Make sure none of their fuses have broken. 

Protect mode

Your subwoofer’s protect mode serves as a warning when it detects a problem with the system. This mode may turn off the sub temporarily to safeguard it. 

In this case, you must first figure out what’s wrong before trying to repair it. The subwoofer will then restart normally, and you may switch off the protect mode

The subwoofer may be in its protect mode

How To Check Common Problems In Car Amplifiers?

In some situations, the amp causes no sound in the subwoofers. It’s also the reason for other problems with the subs, such as clipping or distorted sound. Here are some common issues with the amp. 

Amp clipping

Sometimes you hear a clicking sound from the car amplifier, which shows insufficient power. You will detect that sound when the amp doesn’t receive enough power to run the sub. 

The causes can be the mismatch between your sub and amp. Otherwise, the software is unsuitable for the sub, leading to amp clipping. 

To solve this problem, check your amplifier’s power rating and ensure it gets that much power to work correctly. The problem must come from the speaker wires if you have given them enough power. 

Distorted sound

If your subwoofer’s output gets distorted, closely examine the amplifier and its wires. The contact created by the power cable, head unit, or amp wires might increase distortion in the subwoofers.

You can use high-quality wires and set them at a 90-degree angle to avoid distortion and interface problems when dealing with this kind of issue.

Farting sound

Subwoofers that have been installed wrongly can create farting sounds. To solve the issue, you need to put the woofers somewhere where air can exit while you’re playing music. 

If the issue is still there, check to see if the amp’s impedance matches that of the woofers. Also, check the power. Do not overload the amp since doing so requires larger subwoofers.

In this situation, make the necessary adjustments at the head unit, lower the base boos, and tweak every setting until your woofers stop farting. 

Check the amp carefully


Even when the car audio amplifier is on, you won’t notice the subwoofer output for some reason. You must work with the head unit, power and ground wires, and the car amp itself. If you can’t figure it out, take it to the local car audio store to fix it properly.

Hopefully, you will find this guide helpful. For any further information, please feel free to ask. Thank you for reading!

To find more useful information, this video will show you more tips for fixing amp clipping:

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