Why Does My Sub Amp Get Hot? (Cause & Fix)

One of the biggest enemies of electrical components is overheating and vehicle subwoofer amplifiers are no different. As a result of overheating, it will cause the components to perform less with frequent shutdowns. Also, it will reduce the lifespan of the sub amp. You may wonder why does my sub amp get hot.

In general, most sub-amps overheat because of poor ventilation or bad wiring. Another common reason for amp overheating is due to lack of power or the amp not matching the impedance of the speakers.

This post lets you understand the probable causes of amplifier overheating and how to stop it.

Why Does My Sub Amp Get Hot

Is It Normal for An Amplifier to Get Hot?

Sub amplifiers are special devices that use a significant amount of power. They are designed in a way to boost an audio signal while sending the same to the subs and speakers.

As such, they tend to get hot. Amp overheating is quite normal, especially when you use it for gain setting at a higher volume.

So, it is normal for an amplifier to get hot under certain circumstances. Still, if the amp becomes much hot, it could indicate serious problems. In that case, you may be interested in an amplifier overheating solution.

Whether it is about the components that may have malfunctioned or other signs, frequent amplifier overheating requires attention.

What Causes the Sub Amp to Overheat?

As said earlier, there are several reasons why your sub amp might overheat. Below listed are the common issues that cause a sub-amplifier to overheat.

1. Incorrect Power or Ground Connection

A bad ground or even a bad power connection can cause the amp to get hot. When you use power or ground wires that are too small for your amp, chances are that the amp will overheat.

Besides, it will shut down when it won’t receive enough power to deliver the output you want.

Almost every car amplifier will need an 8-gauge ground and power cable. Moreover, the power and ground wires should be of the same size. They should reach the amplifier from the battery.

2. Misplaced Speakers

If a speaker of your car is grounded to the chassis of the vehicle or is blown, the amp will power them. In that case, the amp will get hot more than usual. You will experience shutdowns regularly.

3. The Amplifier Has Limited Ventilation

There is no denying that if the amp doesn’t have proper ventilation, it will overheat. Following the incident, it will either shut down completely or switch itself to protection mode.

Most issues relating to ventilation are temporary. That way, the amp returns to its normal position after cooling down.

But if the amp faces the problem frequently, it could indicate serious problems. There might be chances of permanent damage to the device, too.

Some amps come with in-built fans for active cooling. You may opt for these types of amps if you don’t have much free space in your vehicle.

4. Too High Settings for Gain and Bass Boost

Settings for gain and bass control are the easiest things to check if your amp keeps on getting hot. The gain control will let the amplifier know how much power you need. When the gain settings are too high, the amp tries to produce more power.

This will lead to sound clipping and distortion from the overheated amp. Whereas, if the gain is too low, the amplifier will make full power but the sound won’t be loud.

5. Low Impedance for The Amp to Handle

When a total load of your subs is lower for the amplifier to handle, it will overheat and will shut down. This is how the device protects itself.

If the car amp isn’t ready to perform well with a low impedance, it will get hot. That’s because the amp can’t make the required power it needs.

6. The Amp Isn’t Strong

When the amp doesn’t make adequate power for the demanding subs, it will make the amp hot. And, this is when you should look for an amplifier overheating solution. Keep in mind that subwoofers will require enough power, especially when the volume is high.

How to Keep Amp from Overheating

Amp overheating is a serious issue that you shouldn’t overlook. In the worst-case scenario, your vehicle might even catch fire. Remember that amps can get hot because of several reasons. Check out the below methods that help fix the issue.

1. Make Sure the Amp Has Sufficient Ventilation

One of the best ways for an amplifier overheating solution is to place it in an airy location. Some people mount them underneath the seat where airflow is less. Hence, mount them where there is free space around them.

If you have in-built fans on the amp, ensure they are working fine. Dust gets accumulated on the fans over time and the blades won’t spin as they should. If the amp is installed in a well-ventilated space and still overheats, other components may be responsible.

2. Double-Check the Installation

When you install an amplifier, ensure that the wiring is correct. If you don’t put the wires as they should be, the amp will produce more heat. Also, it will blow out the fuses. Additionally, the ground and power cables are crucial.

So, make sure that they are connected well. Check if the ground connection is correct, the amp won’t function or turn on if the ground connection is not good. If there is paint on the grounding point, remove the same because

3. Check the Gain Boost Setting

If the amp gain is too high, it will result in sound clipping or distortion. The amp will overheat because you are forcing it to perform hard despite what it can deliver.

On the other hand, if you set the gain too low, it will reduce loudness. You may think that there are problems with the speakers and subs.

4. Inspect the Speakers

Overheating of amps can be related to blown speakers. The common reasons include thermal failure, mechanical failure, or high volume for a long time.

To find out whether or not the case relates to damaged speakers, inspect them manually. Check the wires to ensure that they aren’t in contact with metal surfaces.

5. Match the Load Of Both the Amp and Speakers

A mismatch in impedance is one of the common causes of amplifier heating. Impedance is the amount of load that the speaker puts on the amp. Therefore, a low impedance means that the amp is taking a high load.

When the load is more than what the amp can handle, it will get hot. Hence, before starting the installation process, make sure that the speaker and amp are perfectly matched.

6. Consider Buying Reliable Amps

Low-quality amps consume more power and produce more heat. Whereas, high-quality amps convert electrical power into sound efficiently with less heat. Here are some amplifier classes.

  • Class A amps produce a lot of heat
  • Class B amps produce sound distortion
  • Class AB amps are considered hybrids of the above
  • Class D amps have high power efficiency


By now you have understood that sub-amps can overheat because of several reasons. However, the most common is inadequate airflow when you place the device underneath the seats or in a tight spot.

Hence, make sure that there is a good amount of airflow, correct wire connection, and matching speaker impedance. Still, if you encounter issues, it is better to seek help from a professional.