Subwoofer Not Working But Amp Has Power

7 Reasons Why Is Subwoofer Not Working, but Amp Has Power:

Many possible reasons could cause the subwoofer not to produce sound even with the turned-on head unit. Famous of them are:

1. Subwoofer Not Connected Properly:

That sounds unrealistic, but it’s the most common problem behind such a mess. Your subwoofer may stop working if it is not correctly connected to the head unit, even though it has power. You may face this problem when a car audio system is being used, and wiring cables are either moved or shaken due to shocks on the road.

When this occurs, the wires end up disconnecting from the amplifier, causing it to no longer be able to send sound signals out to your subwoofer. While this problem may seem minor or insignificant at first glance, it can seriously affect your audio system’s work.

2. Incorrect Amplifier Settings (Setting Crossover Too Low):

Incorrect amplifier subwoofer settings, such as setting the crossover too low, can cause subwoofers not to work even though the car amp is powered on. The problem may occur due to the frequency of the bass sound being produced is too high for your speaker system’s crossover setting or beyond its range.

3. Using Faulty Wires:

Sometimes, the problem can be tough to detect even though your subwoofer is working on another amplifier or receiver but not yours, even though the amp is fine. Using poor or faulty wires to connect or power your audio system can make provide instability in making a sound. Sometimes, you can hear sound from the subwoofer too. By appearance, you may see power wires are fine, but in reality, they’ve been damaged or broken from the inside.

4. Subwoofer’s Fuse Went Down:

Some subwoofers, such as powered ones, require fuses to work correctly. A subwoofer fuse is an internal safety component that can save your subwoofers or amplifier from getting damaged completely. A fuse gets blown if too much current passes through the circuit, not letting the over current to the subwoofer. In this situation, the subwoofer stops working even though you have turned on the amplifier.

5. Defective Subwoofer Components:

Simply, a defective subwoofer will not work even though you connect it to any amplifier. Subwoofer’s faulty components may be internally damaged positive and negative terminals, melted voice coil, or torn speaker’s cone. If you see any of these signs in your subwoofer, you can evaluate why your subwoofer has stopped working, even with a turned-on head unit or receiver.

6. Using Wrong Inputs:

That’s one of the most common problems I see whenever a person comes to me with such a problem. Using the wrong input cables on a subwoofer can cause it not to work even if the amplifier is powered on. When you make improper connections, the subwoofer will not catch the signal, resulting in no response.

For example, if RCA cables (stereo) are connected to mono ports and vice versa, then the sound output from that connections won’t be projected correctly. Likewise, connecting a single-channel bass line cable into two channels or multichannel systems may lead to distorted sound quality and improper volume balance in specific frequencies.

7. Activating Protection Mode:

Many subwoofers and amplifiers come with a unique built-in feature like protection mode ⁽¹⁾ to prevent damage. When this mode turns on a subwoofer, it can cause the sub not to work. That’s because when protection mode is enabled, it limits how much power the subwoofer can receive and sets a cut-off point once certain thresholds are reached. This helps prevent damage to the speaker by preventing overly loud or damaging frequencies from getting it and damaging its sensitive components.

5 Steps to Solve Subwoofer Not Working But Amp Has Power:

A few practical steps can help your subwoofer work again, which are given below:

1. Check All Your Volume Control Knobs:

Well, sometimes everything is fine. You just need to make sure that all the control knobs on your amplifier/head unit and subwoofer are not set at a very low level. If you find out they are at the lowest level, increase them. It’s just that simple. You should also need to check the gain knob ⁽²⁾. The gain knob is responsible for the incoming amp channel volume, and if you see it is also set too low, your subwoofer will not give you the output, or you’ll hear minimal sound from it. Also, ensure you have turned off the mute functions on both the amp and sub.

2. Carefully Check Your Input & Output Connections:

When you set up your subwoofer and amplifier, it is essential to connect them correctly. Otherwise, you will not get the sound from your subwoofer. You should also ensure that all cables (including power cables) are securely connected and not damaged.

To begin, turn off your power amp before connecting any wires. Then, connect all of the input cables from your source components, such as CD players or home theater receivers, to the inputs on your power amp using RCA-style connectors. Next, connect an appropriate speaker cable from each output terminal on the car amp to one of the terminals on each connected speaker or subwoofer and ensure these are tightly secured.

3. Ground Your Amplifier & Subwoofer (For Car Audio):

If your car subwoofer is not working while the amplifier is turned on, you’ve not correctly set up the ground connection (power and ground wires) on your car audio. To ground your subwoofer:

1. Start by locating a clean, unpainted metal surface near the subwoofer where you can attach the ground wire.
2. Use a power wire brush or sandpaper to clean the grounding point and remove any paint or debris which may interfere with the connection.
3. Once the grounding point is clean, attach the ground wire to it using a ring terminal or grounding screw and tighten it securely.
4. Run the ground wire from the grounding point to the amplifier or subwoofer, making sure to use the appropriate size wire for both components and that all connections are secure.
5. Use a multimeter to test the ground connection and ensure a low resistance reading (ideally close to zero ohms).

4. Replace Faulty Components Such as Voice Coils, Fuse, or Cone:

You can quickly eliminate the subwoofer problem by replacing the defective parts of your subwoofer. As mentioned above, your subwoofer will stop working if it has torn cone, melted voice coil, or broken terminals. However, replace the damaged components with the same model and new parts to ensure the subwoofer’s life cycle. Also, you need to change the internal fuse wires if your subwoofer has gone short-circuited. 

5. Do Proper Amp Settings (Correct Crossover Settings):

Proper car amp settings or correct crossover settings can make a subwoofer work again. All speakers should have a crossover setting configuration suited for the type of speaker. Usually, you can set subwoofers to around 80 Hertz (Hz). When configuring the amp settings, you will need to adjust both the preamp and subwoofer output levels accordingly to get optimal performance from your system.

The preamp helps modify any frequency highs or lows within the audio signal and adjusting it can help reduce specific frequencies that may be too loud while preserving others that might be too quiet. This adjustment should also include a low-pass filter, depending on whether you use an active or passive subwoofer system.

Other Quick Troubleshooting Steps:

You can also follow the quick and initial steps to fix your subwoofer:

1. You must ensure that you have enabled the sub in the settings. For this, you need to open Settings, go to the Speaker option, and open the Speaker SP. Once you have opened it, confirm the speaker pattern doesn’t end at 0, as the sub won’t work at that level. Besides, make sure it ends at 1 or 2.
2. If you are using an active subwoofer (aka powered), check the volume knobs at its back and set them correctly.
3. Ensure your subwoofer is not on the standby function. If it is, just turn it off.
4. If the LED indicator light on the A/V receiver is not lit, you may need to investigate further. Firstly, ensure that you are receiving a low-frequency effect (LFE) signal from your chosen audio source; if not, try changing the sound field setting to AFD Auto or another option. If you have a Sony receiver, it will send out a simulated LFE signal which should light the SW indicator. If all of these attempts fail, then it could be an issue with your subwoofer, so check all connections and cables are correctly secured. Lastly, test using different sources of audio if possible.
5. You must also ensure that the subwoofer is plugged correctly into the active AC cord. However, if you have a faulty power cord or it is non-active, your subwoofer will not work.

Steps to Fix Subwoofer With No Sound:

You can fix the subwoofer with no sound by following some simple steps below:

1. Confirm that you have securely plugged the power cord into an electrical outlet, and the power reaches the subwoofer. If you still see no sound even though all the connections are okay, check any switches or circuit breakers and reset them as necessary. 
2. If the above step fails, you should double-check all the connections between your receiver/amplifier and subwoofer and ensure they are securely wired up with tight connections. Furthermore, look for damaged wires and replace them if necessary using the correct wiring configuration in the user manual of your audio system.
3. As mentioned above, you should also ensure that you have correctly tuned the receiver/amplifier using its volume control knob (bass knob included) or adjusting its tone controls. Also, select the proper amp’s input mode(s) on the receiver/amplifier depending on the signal sent from other components (audio mixer, etc.).