What are the causes that make a car amplifier hot

Last Updated on November 6, 2022 by Devon

You may have heard or read somewhere that the main cause of an amplifier getting hot is the power supply capacitor inside. But why, exactly? Why are they getting so hot? what are they doing that requires them to get hot? And most importantly, how do we prevent this from happening?

To answer the question, What are the causes that make a car amplifier hot? let us first understand what an amplifier is and how it works.

What is an Amplifier?

Crunch PX1000.4 Power Amplifier review

An amplifier takes a small signal larger, or stronger. It can also make a large signal smaller, or weaker, but this is not its main function, as there are other components that do this job better than an amplifier.

The most important components in an amplifier are the power supply, which is also called the “battery” (even if there’s no battery inside), transformers and capacitors, all of which will be explained later.

A typical car audio amplifier has 4 main parts: the front end, preamplifier circuit, power supply, and the output stage. All of these components are connected to each other in series, with each one feeding off the signal from its predecessor.

The front end amplifies the input signal (from your radio receiver or any source) and feeds it to the preamplifier circuit. The preamplifier will further amplify this signal and give it a specific flavor according to what you have pre-set with your audio processor or equalizer.

This signal is now rich in bass, mid-range, and treble as well as other flavored components like compression and loudness. This signal is then fed to the power supply which will further amplify the signal by supplying power (voltage and current) to the amplifier. The output stage will then further amplify the signal according to the gain of your amplifier (either fixed or variable).

Now, if you were not satisfied with how it sounds, there is only one thing left to do: Feed this amplified signal back into itself! That’s right; You can feed this signal to its input, and it will go through the front end again and get an even stronger signal than the previous time.

Since you’ve increased the strength of this signal by many times, your amplifier can now handle a much bigger power output (measured in RMS) and drive your speakers accordingly. But don’t forget: With great power comes great responsibility!

What are the causes that make a car amplifier hot?

What are the causes that make a car amplifier hot - Guide

The long answer: As a signal is passed from one amplifier stage to another, the voltage and current will be amplified. This means that by the time the signal reaches the final output stage, it’s already been greatly amplified. Now imagine what happens if your speaker suddenly needs the full power of this signal all by itself.

To begin with, it can’t handle that much power at once and your speaker starts to overheat! The next thing that will happen is a distortion because the amplifier will try to push more voltage and current than what your speaker can take. This results in bad sound from one or both speakers.

The short answer: An amplifier gets hot because it amplifies a signal too much, and your speakers can’t handle all that power. This results in over-amplification and distortion of your music before it reaches the speakers. And when this happens, you’ll either get a bad sound or sound that goes above the normal range, which is called clipping.

How to Prevent Amplifiers from Overheating?

There are two ways of avoiding overheating in amplifiers: First, you can get a bigger amplifier that is able to handle the power your speakers will give it. Second, you can choose not to overdrive your amplifier. This means choosing the right size amp for your speakers while avoiding clipping.

We’ll discuss why you shouldn’t overdrive your amplifier in the next chapter titled “What are Clipping and Distortion?” For now, let’s see what happens when you get a bigger amp…

According to Ohms Law, the current through an amplifier is directly proportional to its output voltage (P=IE; Power = CurrentXVoltage). That means that you can reduce the current by changing the voltage. So, if your speakers need 500W of power and your amplifier’s maximum output is 1000W, it will get hotter than if it had a maximum of 800W (even though it would still be overdriving your speakers).

What are Clipping and Distortion?

Clipping is the over-amplification of a range of frequencies in your music. The result is often a very sharp sound devoid of any bass or warmth, with the treble pushed up to unnatural levels. This usually happens when you turn up the volume too much on your radio receiver or amplifier.

Distortion, on the other hand, is damage to sound quality caused by turning up an amplifier too loud for your speakers to handle. Distortion usually happens when you turn up the volume of your radio receiver or amplifier beyond its maximum “clean” level and can’t be avoided completely in any system, but it’s easier to avoid with bigger amplifiers.

Is it bad if your car amplifier gets hot?

Yes, your car amplifier should not get hot. When it gets hot it draws more current and this can cause problems with the electrical system of the car.

When driving at full power for a long time, the electrical system of the car cannot handle it and will eventually overheat which can damage components in your vehicle’s electrical system. While there are some amplifiers that will shut down before they overheat, this is usually only if your amp gets too hot during normal use. This can lead to expensive repairs or even buying a new car stereo.

The best thing to do is turn down the volume on your amplifier when you are not listening to music through it. While there are cases where an amplifier will overheat if you drive through a puddle or it gets wet, this is usually only during very heavy use (such as playing the bass very loud at parties) and should not happen during casual use.

If you experience your car amplifier getting hot for no reason, then you may have a faulty amp that needs to be serviced. It is recommended that you turn down the bass and do not play it loud for an extended period of time. If this does not help, then it may be best to replace your amplifier as there may be internal damage such as a blown fuse or damaged circuitry that will need to be repaired.

Can a car amplifier catch fire?

An amplifier fire caught the attention of vehicle owners nationwide. The Ford Motor Company (Ford) has officially recalled certain models to avoid accidents, injuries, and damage because of being caught in a fire. Of the two million vehicles recalled by Ford because of defective amplifiers, one was involved in an accident that caused injury or death before it could be repaired.

The Ford Taurus Amplifier Recall (2006) was for all three generations of the Ford Taurus that were produced from 1991 to 2005. Fire damage occurred when an amplifier harness connection ignited causing the fire. The defective equipment resulted in 327,000 vehicles being recalled by Ford who offered free repairs.

However, this is not the only instance of a vehicle fire resulting from defective car audio systems.

The Kia Sorento Amplifier Recall (2006) and the Hyundai Sonata Amplifier Recall (2004) were both for large SUVs that put drivers at risk for injury or death. Both cases resulted in recalls because of overheating due to defective amplifiers causing fires.

These were separate recalls however both resulted in the same outcome. Fire damage to the vehicle’s interior, exterior, and engine was reported before being recalled by Kia and Hyundai respectively within twelve months of their manufacture date.

How do car amplifiers cause fires?

The fuse that runs through an amplifier wiring circuit can be faulty or incorrectly installed.

When the car is turned on, currently runs through this fuse until it reaches the amplifier to supply power. If the insulation coating over the wiring becomes stripped or punctured then there is an increased risk of fire because of electrical resistance that occurs when electricity flows freely through a partially open circuit within the wiring system.

The wire harness within the amplifier is meant to protect wires from touching each other and/or anything that could cause an electrical short. When the wire harness is punctured or the insulation becomes stripped then there is potential for damage to occur.

This can be most common when an aftermarket audio system has been installed in a vehicle by someone who does not know what they are doing or does not care.

How can I detect a faulty amplifier wiring harness?

The best way to avoid injury and damage is to do research and compare prices at reputable car audio stores (such as Crutchfield). For starters, you can search online for reviews on car amplifiers before purchasing one. If there are no ratings then it may be best to look elsewhere.

If you do not trust yourself with a wiring work then seek professional help through your local car audio store where you can ask questions and show them the product.

Many reputable stores will allow customers to open and inspect their equipment and in some cases even install it for them (though there is often an installation fee). A faulty wire can be detected by sound and feel when the fuse harness is touched.

The faulty wire will emit a buzzing sound while it’s fused with power on. The wiring should also not feel hot to the touch during the operation of an amplifier so if you find yourself in this situation then there may be a problem.

Amplifier fires are not something to take lightly, but if you are careful and know what to look out for then the chances of having a faulty wire harness within your amplifier are very slim.

Related Article: Why my amplifier power wire melts and how to fix it in 2023

How do I prevent an amplifier fire?

The best way to avoid injury and damage is to follow the steps above. Before buying an amplifier always research it first. If you are installing an aftermarket audio system yourself then take your time and be meticulous when making connections.

Be sure to inspect the fuse wires if they do not feel stiff or too loose when touched together. Do not overload your amplifier with more power than it’s rated for and follow the wiring instructions that come with it. Keep the interior of your vehicle clean and free from clutter.

If you have a faulty or “knicked” wire harness then it may be best to consult a professional car audio technician before continuing with installation because it could save you time, money, and property damage down the road.

In some cases, though it is not practical to pay someone else just to install an amplifier so it is best to know what you are doing before attempting installation yourself.

What Causes an Amplifier to Overheat?

Amplifiers can overheat for a number of reasons. The most common reasons are Malfunctioning Fan / Fuse / Auto-Reset Circuitry Failure, Volume too High or Low, Running an Amplifier Without a Capacitor, Incorrect Power & Ground Cable Lengths, Improperly Installed / Insufficient Cabling.

Why do some car amplifiers blast?

The question is, why are some car amplifiers blasted? Some systems sound the same clear and clean. There are other systems that get really loud but don’t sound that great. The reason for this disparity is quite simple: the quality of equipment used in making the system.

There are only three components in an audio system; speakers, boxes, and amps. If one of them doesn’t sound right, it’s not because the speaker or box is bad; it’s because the amp isn’t good enough to make up for its inadequacies.

The first thing that comes to mind when buying an amplifier is power output. It doesn’t matter if you can afford $5,000 speakers; if you have a $50 amplifier, it can’t drive the speakers properly.

But there’s more to amps than power output; it has something to do with the cleanness of sound as well. There are good and bad amps out there that can deliver low power but still sound great or deliver high power and sound like junk.

How hot is too hot for a car amplifier?

Well, that depends on whether you like to take risks. Car amplifiers can handle heat up to 160 degrees Fahrenheit (71.111°C). However, if the amplifier runs too hot for an extended period of time it will burn out and fail so it’s best to play it safe and never run your amp above 160F or 72°C.

For those of you who dare to take the risk, and probably live in warmer climates than where I live (Seattle Area) then you might be able to push it a little hotter.

If your amplifier is not putting out the power that it should then follow this guide to take some measurements before dashing off and buying a new amp. First, find out what the specifications are for your amp. If you have misplaced your owner’s manual then check out the manufacturer’s website because all of that information should be available to download for free.

If that doesn’t work then you can always go to a car audio shop or another car stereo enthusiast and see if they have it on hand. Now that you have the amplifier’s specs it’s time to take some measurements with an amp clamp. Place your DMM red probe on the positive battery terminal and the black probe on the battery negative.

Make sure that your probes are not resting on any metal while taking these readings because it will cause a false reading.

Now adjust your meter for DC voltage or switch it to the AC voltage setting if it has one. With your meter set to 20 volts DC or more, check that you are getting at least 14.5V with the engine running and the stereo turned up full blast without touching any wiring or other components.

If you are not reading at least 14.5 volts then this is an indication of a wiring problem so recheck all of your connections to make sure there are no loose grounds or bad speaker wiring.

If you are reading between 14.5 and 15 volts then your voltage is fine but if not, then there may be a problem with the amplifier’s output stage which is likely to fail in a very short time if it overheats.

Now it’s time to check the maximum output of your amplifier because you should never run an amplifier at full power for very long or you may damage it. With everything still hooked up as before, turn down your stereo until no sound is coming from your speakers and switch on your amp with the master volume all the way up.

If you have an amp with multiple channels then select the one that you are using.

The reading on your DMM should be set to DC volts again and now measure the voltage across both of your amplifier’s outputs. This will give you a reading of what is called “dynamic” or Max. output voltage depending on your amp’s model number. If this reading is lower than 13.5 volts then your amp may not be able to play at full power for very long before it overheats.

If you are seeing higher voltages then again, your amplifier’s output stage has a problem that will most likely cause it to fail if its temperature is not kept within the proper range. To keep an amp running at its maximum possible efficiency it is always best to use a capacitor.

However, if you want to keep costs low then use a small one such as the MV-38/39 from Panasonic because these little guys are cheap and will not affect your sound quality.

If you need an amp with more power then check out the rest of our car audio amplifiers. If you just need more bass then go with an aftermarket subwoofer amplifier or a mono amp that is capable of bridged operation on two subwoofers wired in parallel to double the RMS power handling.

How do I know if my car amplifier is overheating?

The most common sign of amplifier overheating is shutdown. When your car amplifier has shut down it will not produce any sound, that’s why you’ll need to check for other issues like the blown speaker or bad connection (fuse).

However sometimes even if the amp doesn’t shut off, you can get signs of overheating like popping sounds, distortions, and shutdowns. These problems will be more evident when you start to turn up the volume or increase bass levels.

Related Article: 7 Signs of a bad car amplifier-Guide 2023

Is it safe to keep driving my car with a blown fuse?

Yes, it is safe. The worst that can happen is that some of the lights and buttons on your dashboard won’t work until you replace the blown fuse.

My car amplifier is overheating but the lights and buttons on my dashboard are working, why?

It’s important to note that not all car amplifiers shut down when they get too hot, some amps can keep working even if they’re overheating and produce lots of heat. So it’s very important that you check for other signs like distorted sound, popping sounds, and shutdowns.

How do I know if my car amplifier is shutting down due to overheating?

Amplifiers shut down when they get too hot (most of the time). If your amp keeps working even though it’s overheating you most probably have a shorted speaker wire or bad connection somewhere in your speaker system.

My car amplifier shuts down after a while, why?

It’s important to note that the amp doesn’t shut down immediately when it reaches its maximum temperature threshold. The shutdown process takes some time because the heat has to travel through wires and other components before shutting the amp off.

Some amplifiers will shut down immediately when they reach their maximum temperature threshold, but the larger ones usually take some time before shutting down.

How can I prevent my car amplifier from overheating?

You should always use proper size heat sinks if your amplifier doesn’t come with one. Most amplifiers come with small heatsinks that are not designed for running at high power for extended periods of time. This is why you should always use an additional bigger heatsink if your amplifier doesn’t come with one.

You can also increase the ventilation around your amplifier by drilling some extra holes into the dash, truck or any other car interior panels near your amp.

What are the best car amplifiers to prevent my amp from overheating?

Amplifiers that run on low voltage are better than high voltage amplifiers when it comes to preventing them from overheating. So if you’re planning on running your amp at its maximum power for extended periods of time, then I would recommend getting amps that run on 12 volts (single or two-channel). You can also install a cooling system.

If you have any questions about What are the causes that make a car amplifier hot or comments concerning anything we have discussed here then send us an email and we’ll try to help as best as we can. If not, then thanks for stopping by our car audio blog, and come back soon for more great articles.

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