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How to Keep Your Amp From Overheating

A car amplifier can overheat for a variety of reasons. In general, it’s because of lack of airflow being mounted in a confined space such as underneath the seats.

Blown/grounded speaker(s), poor power and/or ground connections, too low impedance load, or gain/punch bass control settings too high, are also some of the most common reasons that can make an amplifier overheat.

Regardless of the problem’s source, an overheating amplifier isn’t something you want to let linger. Your amplifier could sustain serious, if not permanent, damage.

With that said, don’t wait until your amplifier shuts down and goes into protect mode. Read on to learn what can cause your amplifier to overheat, what to do if it happens to you, and how to keep your amp from overheating.

How to Keep Amp From Overheating

1. Invest in a Quality Amplifier

Rockford Fosgate T1500-1bdCP

Cheaply made amplifiers are highly likely to overheat than quality ones that are designed from the ground up with quality in mind. So, investing in a brand name amplifier that’s very efficient will save your from overheating problems.

The efficiency of an amplifier lets you know how much of the electricity fed into your amp is converted to an audio signal and how much is wasted as heat.

Quality amplifiers use the electrical power that is supplied by the battery and alternator in the most efficient way possible.

Additionally, brand name amplifiers are fitted with beefy components and are designed to efficiently dissipate heat away from amp’s internal structure for long term performance and reliability.

Cheap amplifier on the other hand waste more power than they actually produce in sound. That wasted power turns into heat, which leads to overheating problems.

So, investing in a good, brand name amplifier from the get-go is one of the best ways to avoid overheating issues.

Car amplifiers come in a number of class (A, B, AB, and D). An amplifier class refers to the way an amplifier combines power and signal.

  • Class A design is the least efficient but has the highest sound fidelity.
  • Class B design is a little more efficient, but full of distortion.
  • Class AB design offers power efficiency and good sound.
  • Class D design has the highest efficiency but isn’t quite as high-fidelity.

2. Ventilation Is Key

Mounting your amplifier in a well-aired location is highly recommended to prevent overheating problems caused by lack of airflow. So, to increase airflow, consider increasing the air gap between the top, bottom, and sides of the amp.

If your amplifier has a built-in cooling fan, check to make sure the it’s turning on and working properly. Additionally, make sure you are not blocking the fan intake.

If your amplifier is mounted in a well-ventilated location but you still have an overheating problem, you can opt for a cooling fan; this will blow the heat away from your amplifier keeping it running as it should.

Check this page for a step by step tutorial on how to add a small cooling fan to your amplifier.

3. Avoid Impedance Mismatch

Impedance – measured in ohm – refers to the amount of electrical resistance, or load, a speaker puts up against an amplifier’s output. The lower the impedance, the higher the load on the amp (and the harder it has to work).

So, the question that’s begging to be answered is: Are your speakers or subwoofers wired together at an impedance the amp is stable at?

Well, it’s worth mentioning that pairing a 1-ohm speaker(s) up to a 4-ohm amplifier will put a lot of strain and overtax the amplifier, making it get hot so fast and shut down.

Another most common impedance mismatch is when you wire a couple of 4 ohms subs in parallel and end up with a 2 ohm load, then bridging a 4 ohm to that load.

The amplifier then is presented with a low impedance load and tries to keep up with it, but heats up due to the extra power it’s trying to push out. Once it gets too hot, it shuts down to protect itself.

4. Inspect your Speaker(s)

If you have a speaker that is “blown” or is grounded to the chassis of the vehicle, the amplifier will get hot very quickly trying to put power to it. Furthermore, sometimes when mounting a speaker, one of the wires will become loose and may touch metal causing the speaker to short out.

So, if your amplifier is getting hot fast after running for little while, make sure the speakers or subwoofers are not blown, and check to make sure they are not grounding out.

5. Avoid Inadequate Power/Ground

If your amplifier is constantly blowing fuses, shorting frequently, or abnormally overheating, it is commonly due to improper ground.

Additionally, if you’re using inappropriate power or ground cables, you may also experience thermal shutdown because the amplifier doesn’t get the power it needs to operate properly.

That said, the wiring kit you use to connect your amp to your car sound system is as important as choosing the right car amplifier.

To operate efficiently, an amplifier needs its power and ground wiring to be large enough to accommodate its demand for electrical current.

As a general recommendation, we follow the guidelines below as a quick reference in determining the appropriate wire gauge.

Wire Gauge SizeTotal Amplifier RMS Wattage
0/1 AWG1000+ Watts
4 AWG400-1000 Watts
8 AWG200-400 Watts
10 AWG100-200 Watts


Furthermore, if the ground connection is poor, or it isn’t connected at all, the amp may fail to turn on or not work very well. Ground problems can often be fixed by cleaning and tightening the ground connection or re-routing it if necessary.

It must be noted that the length of ground cable should be less than 18 inches long, the shorter the length of wire the better. For the best possible grounding, the ground cable must be bolted directly to a solid, thick steel part of your vehicle chassis.

P.S: Make sure to remove any paint or primer from the point you choose to use as your grounding point. A properly grounded subwoofer amplifier will deliver clean, noise free signal.


6. Adjust the Gain & Bass Boost

Generally speaking, maxed out gains, and excessive bass boost should be avoided at all costs.

Properly adjusting your amp’s gain and bass boost settings will not only raise the sound level, but it’ll also greatly increase the sound quality of your music.

The purpose of the gain control is to level match the head unit’s output voltage to the gain structure of the amplifier. A properly adjusted gain reduces background noise, distortion and prevents amp clipping.

If you have the gain set too high, you’ll have problems with distortion and “clipping”. If the gain is set too low, the subwoofer might not sound as loud as it should, and you’ll think you aren’t getting much volume.

If you are experiencing distortion in the form of clipping, you may need to buy a larger power amplifier or live with lower volume levels. Proper gain setting is important to avoid clipping.

7. Proper Mounting

The way your amplifier is designed dictates how it should be mounted for better heat dissipation. Therefore, knowing how to mount your amp properly is a big deal in preventing and cutting down thermal buildup inside the case.

An amplifier that’s improperly mounted will be trapping a lot of heat in between every fin of the heat sink.

That said, since each car amplifier is build differently, orientating the amp so any cooling fins/channels in the amp casing are running vertically is the best way to allow for better cooling.

You never know! Sometimes little things like this can make a huge difference.

8. Clogged Internal Airway

Finally, clogged internal airway is easily one of last thing you’d think you need to check if your amplifier is constantly overheating. Been there…done that.

We’ve come across a number of car audio applications in which the amp overheats and jumps into protect mode for no obvious reasons. Only to find out later that the amp case is clogged with dust accumulation and other debris. The latter significantly reduces the cooling power of the heatsink by lessening the surface area available for cooling. Eventually, the amplifier may begin to overheat due to this lower cooling power.

Alex Brown

Hey There, my name is Alex Brown, I'm an LA-based sound engineer with over 10 years experience installing, troubleshooting, and repairing commercial, automotive, and household sound equipment. I've installed highly competitive car audio systems, and everything from navigation systems to full car stereo systems, remote starters, alarms and beyond. I enjoy creating solutions and simplifying everyday needs. I also love helping people get great sounding gear, thereby, saving the world from bad sound one customer at a time.

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