Amp Has Power But No Sound From Subwoofer or Speakers [SOLVED]

Norvan Martin
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An amplifier improves sound quality by driving your speakers and subwoofers with additional power. This means that if your amp experiences any problem, the quality of the sound may considerably deteriorate. One such issue is the common problem is the amp has power but no sound.

In this article, we will troubleshoot this issue where your amp has power but no sound from your subwoofer or your amp has power but no sound from your speakers.

The likely cause of this issue is overheating, overcurrent, overvoltage, a fault in the power system, a blown amplifier, a blown output channel, or a blown fuse.

Let’s explore this in more detail. 

If there is no sound at all being produced by an amplifier after it has been powered, then the following are some of the possible causes:

  • Overheating
  • Overcurrent
  • Overvoltage
  • Fault in the power system or blown amplifier

An amplifier that is overheated often has an overvoltage or overcurrent issue and may experience gross distortion of sound.

However, if the problem is not checked in time, the sound may disappear completely.

Additionally, blown amplifiers will stop working instantly as no sound signals will be delivered to the speaker units. However, you may still be able to power on the amplifier even after it’s blown. Let’s discuss this in better detail.

1. Overheating and Overcurrent or Overvoltage

There may be many problems causing your amplifier to overheat. Some of these are:

  • Overpowering the amp
  • Faulty circuitry 
  • Running the amp for a very long time 
  • Overloading the amp
  • Running the amplifier in direct sunlight or near hot surfaces
  • The cooling system of the amp is faulty

When an amp is overheated, it will go into protection mode. However, if the overheating is a result of overcurrent or overvoltage, it is more likely to blow than go into protection.

amp overheating

If you notice that your amp is running very hot and not producing any signal, switch off the power, disconnect the appliances, and inspect and resolve the issues causing the overheat.

2. The Power System Is Faulty

One of the problems that is likely to cause the sound signal to disappear from your amp is a fault affecting the power system of the amplifier.

It is either the wiring system is not properly done or the remote is not working properly. If you have the necessary technical skills, check and adjust the wiring so that the amp can be properly powered.

3. A Fault In The Remote Wire

Amplifiers are normally controlled by a remote system. If the power button of the remote is off, your speakers and subwoofer will not receive any sound signal from the amp. 

The same thing happens when the remote is on but the wiring system of the remote has a fault. Try to power on the amp manually. 

Also, check the battery layout in the remote system.

The remote will fail to work if the batteries are not properly laid or the wires from the battery unit are rusted or disconnected. 

To correct this problem, remove rust from remote wires, lay the batteries properly, connect broken wires, and check that the remote is working properly.

4. A Faulty Power Wire

Power wires deliver current to the amplifier. Power signal wires connect your amp to the speakers or subwoofer. Any of these wires might have burnt out. If for example, the gauge of the wire used is incorrect, this could easily happen.

amplifier wiring

This happens because some of the energy used to drive current through the wires is converted to heat.

Very thin wires experience more heating and the wires may burn out if they cannot sustain the current. This may be the cause for the sound signals not reaching the speakers or subwoofer. 

A remedy for this is to ensure that all wire sizes correspond to the allowable quantity of current.

On the other hand, incisions and corrosion may also affect the current flow through the wires. If any of the wires are affected by corrosion or incision, they may not deliver sufficient power to the amp.

The amp may therefore turn on but will not have enough power to drive the subwoofer to produce sound. 

Switch off the mains when handling power cables and repair or replace damaged wires. You can use a multimeter to check the cables for the presence of voltage and replace faulty wires. 

5. Impedance Mismatching 

Amplifiers are designed to handle speakers and subs of specific impedance levels or ranges.

There might be a challenge of unmatched impedance between the powered speaker or sub and the powered amplifier, if either the speaker/sub impedance is too high or too low to be supported by the amp.

If your subwoofer draws too much current from the amplifier, the system may be overpowered and jump into protect mode. However, if the sub draws too little current due to a massive impedance difference, you will not hear any sound either. 

If your amp is rated 4 ohms, the subwoofer should also be 4 ohms rated, and so on. Replace mismatched subwoofers or amplifiers depending on which component is easily accessible, or cheaper to replace.

Check if the protect mode lights are still on. Also, if the lights are on but the amp is properly matched with the subwoofer, the subwoofer itself, the subwoofer cables, or even the other components connected to the amp could be faulty. 

6. Polarity Mismatch In The Speaker Connection

Another possible reason why there is no sound signal from a powered amplifier might be a misalignment of the polarities in the various ports.

If the polarities are interchanged in the case of speaker wires connecting the amplifier, we expect no sound to be produced.

You should therefore check the wire connections to ensure they are connected in the right way.

7. Blown Fuse

Subwoofers have built-in fuses or circuit breakers for self-protection against overcurrent.  if for example there is a current surge or short circuit, the subwoofer will not power up.

blown amplifier fuse

If you have tripped circuit breakers, this is likely the issue. Before replacing a fuse, however, you should find the fault that caused it and rectify that first. 

8. Volume Issues

This may seem simple, but sometimes the issue is as basic as a volume problem. Make sure you check the volume levels and ensure that everything is set properly. Check the volume levels on the amplifier and the base unit. Sometimes subwoofers have volume problems for different reasons. 

9. Check For A Short Circuit

A short circuit is a common electrical problem that can certainly cause this issue. Generally, a short circuit often causes your fuse to blow, but now always. Short circuits are caused by unexpected increases in voltage levels somewhere in the circuit.

This may be due to two wires that should not come into contact making contact, for example. This is why the fuse should blow and interrupt the functioning of the system so that excess current does not damage the device. 

To check for short circuits, make sure you check:

  1. Look for physical signs like visible burns or melted metal on wires, burning smells, or flickering lights.
  2. Use your multimeter resistance or continuity setting to confirm the voltage
  3. Check the positive and negative terminals of the subwoofer

10. Protection Mode

Many audio devices like speakers and subwoofers often have a protection mode. This mode is enabled whenever the device detects an issue with the system that can cause damage. Check your specific model (consult the manual) to see if it has a protection mode and if this mode has been enabled.

If so, you need to check the rest of the system for issues such as short circuits, connection issues, overvoltage, and so on. Make sure you fix the issue that caused the subwoofer to go into protection mode before trying to turn on the subwoofer again.

11. Check the Amplifier Subwoofer Settings

This may seem to be a simple issue, but your subwoofer settings may be the problem. You need to ensure that your subwoofer settings are accurate and that nothing was changed unknowingly. Here are some common issues:

  1. The subwoofer (especially aftermarket ones) may have been disabled in the sound system settings. Ensure that the sound output is turned on and the dB level is higher than 0.
  2. Ensure that the amplifier frequency settings are correct (LPF and HPF)

12. Ensure The Amplifier Is Grounded Properly

Amplifiers are high-power devices so they normally require grounding. If your amplifier detects that there is a grounding issue, it may go into protect mode and won’t pass on any signal to the speakers or subwoofer.

In addition, check that the amplifier’s ground and power wires are OK. You can use your multimeter’s continuity tester for this purpose. Also, inspect them to ensure they’re not loose at any point.


How Do Amplifiers Work?

Before we can look at the possible reasons why there is no sound, it is good to know the basic working principle of an amplifier from the input side to the output side.

how do amplifiers work

Once we develop this understanding, we will be in a better position to decide on the best troubleshooting methods to apply. 

An amplifier boosts the sound signal from your music source and supplies that boosted signal to your speakers and subwoofer.  

Audio amplification is described as the process that increases the magnitude of an audio electrical signal. It may sometimes distort the electrical signal on the output of an amplifier due to the magnitude of the signal. 

If we take into consideration an amplifier that is powered by a voltage of let’s say 12 volts as is the case for many amplifiers, the output alternating signal cannot have a voltage greater than that or clipping will occur. 

FAQs

How to Fix an Amp With No Bass

One common issue is that your amp turns on, but there’s no sound. This can be due to a variety of reasons, including:

  • Amp doesn’t detect input
  • Volume too low
  • Headphones plugged in the wrong jack
  • Headphones aren’t connected properly
  • The amp turned off accidentally by pressing too many buttons at once

The first thing you should do if your amp turns on, but there’s no sound is check all connections. Ensure that the power cord is plugged into the wall and then into the amp. The cord should also be plugged into a working outlet.

Next, make sure that you’re not playing anything from another device, such as a smartphone or laptop. If you have headphones plugged in, make sure they are in the correct jacks and appropriately connected to the headphone port on the front of your amp.

Finally, if your amp turns on, but there’s no sound, and you’ve tried all of these steps, try turning it off and back on again to see if it will work this time. If not, call customer service for assistance with fixing this issue over the phone.

How to Fix: My Amp is On But No Bass is Coming Out

  • Check to make sure that the amplifier is plugged in. Plug the amplifier into a power source, like a wall socket or extension cord, and turn it on with the power button.
  • If you are using headphones, make sure they are plugged in correctly.
  • Make sure that your amp receives input from an external device, like a CD player or turntable, either through the AUX input or the RCA cables if you’re using external speakers.
  • Turn up the volume on your amp. You can do this by turning up the knob on your amp until you hear sound coming out of your external speakers or headphones.
  • Try plugging in different audio equipment to see if they work correctly.

Why Is There No Sound Coming Out Of My Sub?

First, make sure that it is not a setting issue and adjust the sub’s stereo settings correctly. Check to determine that the sub-cables are securely connected to the amplifier. Inspect the amp input and output, as well as whether it is operating at the recommended voltage.

How To Fix No Bass Output But Amp Is On?

There could be a problem with your amp’s power system if it is turned on yet is not providing any output to your subwoofer. If the amplifier wires are properly connected, check whether the remote’s power button is on or not.

What Do You Do When Your Subwoofer Stops Working?

First make sure all the connections; speaker wires, outlets, power cable, and fuse are functioning properly. Check and test them all for damage, disconnections or improper fitting. Next, go over the system and menu settings. If connections are damaged, replace them with functioning ones, once sure they’re working properly, switch the subwoofer back on and set the volume.

How Do You Diagnose A Subwoofer Problem?

Test the sub by tapping very lightly on the center conductor of the other end of the cable. You should be able to hear a pounding sound from the subwoofer if it is turned on and calibrated appropriately. If you don’t hear a responding sound, there could be a problem with the subwoofer.

Conclusion

As observed, several problems can be attributed to the lack of sound even though your amp is powered. It is therefore recommended that you troubleshoot your different devices, connections, and components before connecting and trying to run them. 

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Norvan Martin is the founder of BoomSpeaker.com. He is a professional Electronics Engineer and is passionate about home theater systems and AV electronics. BoomSpeaker was created as an online hub to share his knowledge and experiences as it relates to home theaters and home audio electronics. My email: [email protected]  Connect on Pinterest and Linkedin