Sub Not Working But Amplifier Has Power - What To Do?

Sub not working? If your amp has power but your subwoofer isn't responding, check your connections and ensure the subwoofer is powered on. It could also be an issue with the sub's internal components.
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Subwoofers and amplifiers can help better the audio system's sound quality. You can experience powerful bass with them. But sometimes you might encounter a common and annoying problem where the sub not working amp has power. 

There is no need for the replacement of your gadgets yet. This article will try to understand and fix the issue when the amp has power but no sound from the speaker.

Subwoofer Not Working, What Do I Do?

There are instances when the subwoofer stops working randomly. It is often because of various reasons like writing issues, blown fuses, wrong cabling, etc. 

As music lovers without experience dealing with a subwoofer or amp problem, the first choice is to contact a technician. 

However, if you come across a situation where you are wondering why did my subs stop working all of a sudden, there is no reason to panic.

Instead of calling a technician, there are some DIY fixes for you to try when your amp is not turning on. 

Why Did My Subwoofers Stop Working?

Usually, when a subwoofer not working with receiver, the issue can be with a blown sub or with connection, wiring, or others. It can also be because of some settings, input issues, short circuits, etc. 

Some of the common reasons why the car subwoofer not working but speakers are working are:

Blown Sub

Blowing off the subwoofer results in no sound or mangled sound. To start, you can look at the sub's structure to understand if there are any issues. High chances are it will look like any broken cone. Else it can be a problem with any coil in the sub.

If this is the reason behind the sub not working, you can find it out immediately. If not, you can continue looking for other reasons. 

Connection Issues

Subwoofers have many connections and wirings. It is possible that there are issues with them, especially when your amp has power supply. Under such conditions, you must check the wires and cables to see if they are loose.

There can also be other connection issues, like breakage, wrong attachments, or damage. Mostly, when the sub is not working, there is something wrong with the connection.

Protect Mode Feature

You can use the protect mode to warn when anything goes wrong in the system. Warning lights will begin flickering if any error or fault is detected, including connection issues, problems, etc. 

You can temporarily switch off the protect mode in these situations. Later diagnose the problem and fix it by switching off the sub's protect mode. 

How Can You Fix A Sub That Is Not Working Even But The Amp Still Has Power

If you do not have any experience on how to fix a subwoofer with no sound, but a working amp, then you might need specialist help. 

But to find a solution on your own, below are some steps that can help.

1: Control Knobs: Check Them Properly

Many users often don't check the sound level of the sub and the amp. The first step is to closely check the volume, bass, and gain knobs if they are powered up. s

When the volume is low, turn it up. It is possible that this is because no sound is coming from the sub. 

Look at the gain knob as well and turn it up. It helps in providing a volume of the system's channel. Finally, check the system's bass knob to ensure it is powered up.

2: Check the System's Input Cables

Another critical reason your amp or subwoofer might not work is the cables. Cable issues can result in transmission loss or issues with audio. 

Ensure that all the input cables get plugged in properly and that there are no loose cables. Also, check the cables for breakage, openings, or cuts. 

Connect the input cable back after inspection. After connecting properly, switch the amp on, and is still no sound, think of changing the cables.

3: Check the Wiring

Each subwoofer has at least two wires. It includes the speaker and the power wires. It is critical to check these wires.

Wiring issues or faulty wires can result in the sub not responding despite amps having power. 

4: Examine the Subwoofer's Fuse

The fuse of a subwoofer is a critical component that helps power it up. But it can bust because of a sudden power surge. 

Because of the power surge, the fuse can blow, leading to a short circuit. You can find the fuse with the help of a user manual. Then replace it if the wire of the fuse is gone.

5: Closely Inspect The Speakers

Faulty speaker wires are the most common reason for subwoofer overheating. A malfunctioning speaker can result in an unresponsive subwoofer. 

If you believe the speaker is damaged, you must replace it. You can purchase a speaker with the same specifications to match your requirement for the receiver.

6: Inspect the Subwoofer’s System Settings

When checking the settings of your subwoofer, make sure it is not on mute or with low volume. It can happen that such setting issues will help with the problem.

Analyze your model's settings and ensure your subwoofer's settings are correct.

7: Check The Grounding of Your Amp and the Sub

You might also have to examine the ground of the amp and the subwoofer. To check it, you can disconnect the battery's terminal, set the multimeter setting, and touch the available test leads for checking the resistance. 

Use the readings and subtract them from future measurements for accurate outputs. Because of the lack of good ground, a hissing sound can result in damage. 

8: Find Out the Requirement of Voltage of the Sub and Amp

Checking the operating voltage for the sub and amplifier can also help while DIY fixing. You have to ensure that the power flows through the amp. While many amps start powering on 8-10 volts, they ideally require 12-14 volts.

How To Buy The Right Subwoofer

When getting a new subwoofer, ensuring it has the right specifications is critical. Below are some features you can keep in mind to avoid issues like the subwoofer amp not getting power.


The first thing you must check is the subwoofer's space compatibility. You should also check if the subwoofer comes with sufficient air volume. Most subs come with ready specification sheets to help check the fit around the fitting area.

Voice Coils of the Sub

Voice coils of a subwoofer can be either single or also double. Getting the single voice coil sub for an easier setup is always better. A double setup will have more flexibility and options if you want to use multiple amps and subs.


When buying a new subwoofer, the power rating is vital. You have to ensure that it matches the power rating of your amp. Choose the active sub if you need a subwoofer without any external source. These subtypes come with built-in amps that are not there in a passive model.

Sealed or Vented Box

You can also use the EBP or efficiency bandwidth product metric to see if your product is sealed or vented. 

Final Thoughts

A sub and an amp help in adding power and bass to your audio. But issues still might arise. With the help of this guide, you can see the multiple reasons and solutions behind for sub or amp not turning on. 

You can go for DIY checks highlighted above when your amp is getting power, but your sub is not working. 

There can be connection issues, wiring issues, fuse issues, short circuits, and others that can result in this problem. Ensure that you thoroughly check everything to resolve the issue. 

Frequently Asked Questions 

How To Find Out If The Sub Or Amp Gets Blown?

You have to check the fuse to determine if the sub or amp is blown. Try using a multimeter and analyze the fuse's circuit, which will help see if it is blown.

Also, when the fuse is blown, it will no longer connect with the rest of the wiring. It is disconnected from all the other wiring to stop any further damage.

How Long Will My Subwoofer Last?

There is no fixed duration for which your subwoofer will last. A sub can stay with you for a long duration if you use it properly. Ideally, these units last for years if you properly care and provide regular maintenance. 

What Is The Cost Of Installing A Subwoofer In My Car?

Installing a subwoofer in your car can cost you around $100. It is the regular installation cost. But the final amount will depend on the subwoofers you wish to install. 

How Much Will A Subwoofer Cost? 

In general, a sub costs around 100-200 USD. But as you get a more specific amount, the features the price will keep on getting higher. 

What Is The Most Common Cause Of A Subwoofer Not Working?

Some of the most common issues behind a sub not working is the connection or wiring of the sub. There are possibilities of leaks, twists, breakage, loose connections, wrong wiring, or corrosion that can result in problems for your sub.

What To Check When My Sub Is Not Working?

When your sub is not working, check your amp has power. After this, you can check the speaker wires, input cables, and other RCA cables to see if they are connected properly.

Check the amp's power wire and settings if the amp has power. Lastly, check the power cables for any type of loose connections.

What Sound Will A Bad Subwoofer Make?

A damaged sub would produce no sound. Else it can have a hissing, static, flat, popping, cracking, or distorted sound. You must inspect the sound at different volumes to see where the problem is.

How To Test My Subs And Amps?

To test the sub and amp, connect them to a sound system and speaker. Try using a multimeter with the process. You can continue changing the channels, volume, bass, and other settings to see the sound quality. 

My Amplifier Has Power Still No Sound In The Sub. How Can I Solve This?

Firstly, check the connections of the sub to ensure the sub is getting an adequate signal. After this, examine the volume, and look for wiring issues and sound system settings. Finally, check if the fuse is blown or if there is a short circuit. In case nothing works out, get professional help.

What Can I Do When My Sub Is Not Working By The Amp Is Switched On?

Disconnect and reconnect the cables. The next step is to try to check if the subwoofer is blown. You can also inspect the settings of the protect mode. If you still face issues even after checks, it is better to get professional help. 

What Could Be Causing Your Subwoofer Not To Work Even Though Your Amp Has Power?

Some common issues can be related to wiring or connections. It can be leaks, breakages, corrosion, and others. It can also be because of some settings, short circuits, input issues, etc. You must thoroughly examine each component to find the exact reason. 

Why Does My Car Subwoofer Randomly Stop Working? 

It is possible that there is some issue with your car subwoofer. Your car subwoofer can stop working randomly because of several reasons. It can be possible because of excessive heat or overload. Or it is also possible that it is not getting sufficient power. There can be issues with connections and ground cables as well. 

When I Start My Car, My Subwoofer Lets Out A Single Thump, And My Amp Goes Into Protection Mode.

What Could Be Causing This? 

The most likely reason is that your car amp is not grounded properly. Moreover, it looks like the RCA is also not shielded. The speaker wires get too close to the ground wires and power. and can cause this issue. You might also want to check your settings to see any issues there.

Why Do Subwoofers Pop When Turned Off? 

All the subwoofers come with their internal amplifier. The pop is not the sub's doing but the amplifiers. Popping is usually the result of a phenomenon when the DV voltage discharges too quickly. It can happen through any coupling capacitor in the amp after it is turned off. 

Does It Matter If A Powered Subwoofer Is Wired To The Fuse Box Instead Of The Battery? 

It eventually depends on the fuse box type and the watts the amp will drive to the sub. Every fuse box has to have a main fuse. So it is better to check the rating of the main fuse.

About The Author
• Editor In Chief
José is a veteran audiophile with an MSc in Engineering, and a passion for sharing his audio knowledge with others.
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