Picture this, you’re cruising down the freeway in your car, vibing to your favorite music, when your amplifier abruptly shuts itself down suddenly. You check the amp and discover it’s scorching hot. This can happen for a variety of reasons, and it doesn’t matter whether your amplifier is new or old. Although the situation is inconvenient, if your amp has not exceeded its useful lifetime yet, there are solutions.
What’s the normal temperature your amp should be running at, and when should there be cause for alarm? What causes your amp to overheat, and how do you prevent that from happening again? Let’s find out!
Amp Temperature: What’s Normal, What’s Not
Your amp is a powerful electronic device, and it normally gets warm while working. In fact, it can get so hot it can’t be touched while still working perfectly. How do you know when the temperature is too high?
The most conspicuous sign of an overheating amp is that it goes into protection mode; it shuts off to protect itself and other audio components. This also eliminates the risk of fire at extremely high temperatures.
Yes, an overheating amp is a fire risk. The amp might not burst into flames, but the materials around its enclosure can. That’s why every amp has measures in place to prevent that.
So, what temperature is too hot? At around 140 °F (60 °C), the metallic parts of your amp will be too hot to touch. At 185 °F (85 °C), the nonmetallic parts will also become too hot and may start to disintegrate. Some amps still keep working at these extreme temperatures. However, the plastic in your amp can melt at such high temperatures, usually around 176 °F (80 °C). Therefore, it’s best to keep the temperature below the melting point of plastic. Also, remember that the hotter your amp gets, the faster it wears out.
Apart from going into protection mode, here are some other signs your amp is overheating:
- Unstable operation
- Clipped audio
- Smoke from the amp or its surrounding
- Constant turning on and off
- Problems with switching on
- (Worst case scenario) fire
If your amp is getting hotter than it should, you need to know the cause and find a suitable solution.
Why Does My Amp Get Hot and Shut Off?
Excessive heat damages electronics by hindering how the components function and reducing the life span of the devices. So, what causes overheating in amplifiers? There are a few possible reasons, and we’ll go through them now.
The quality of your amplifier fundamentally determines how easily your amp gets hot. Amplifiers are divided into classes depending on how efficient they are, their audio quality, and how much power they produce. Knowing the class of your amplifier will tell you a lot about the cause of overheating.
Class A amps produce high-quality sound but produce a lot of heat. Class B amps are more efficient but have less sound quality. Class AB amps combine properties of class A and B amps, delivering excellent sound quality and better efficiency. Class D amps are the most efficient, but they have the lowest quality sound. Class AB amps are good for sound quality and power efficiency.
Ventilation is another common cause of overheating in amplifiers. If your amp shuts down due to poor ventilation, it usually turns back on when it has cooled down sufficiently. Check the location and ensure the amp is well-ventilated and not cramped.
You might have one or more blown speakers or speakers grounded to the car chassis. Your amp will still power the faulty speakers, but it will get hot quickly. Blown speakers can easily be recognized because they won’t work correctly. You can also check the wiring for issues.
High Gain and Bass Boost Settings
Setting your gain and bass boost too high will force your amp to produce full power immediately, which can easily cause the amp to overheat.
Improper Power or Ground Connections
Your amp can overheat if your power or ground wires are too small (too thin) because they cannot give it all the power it needs. The ground and power wires should be the same size and run directly from the battery to the amp.
Powerful speakers need a lot of energy to run. If your amp cannot provide enough power, it will quickly overheat.
Your amp may overheat and shut down if the total load of the speakers is lower than your amp can work with. A common mistake is connecting two 4Ω woofers in parallel and bridging them to a 4Ω amplifier. The amp cannot work with the resulting 2Ω, and thus it gets very hot.
Amplifier Overheating Solutions
If you want to prevent a recurrence of an overheating problem or prevent your amplifier from getting too hot in the first place, here are a few ways to keep your amplifier cool.
Keep the Volume in Check
More volume means more power from the amp. Therefore, listening at a reasonable volume will keep your amplifier cool.
Use a Proper Amplifier
Pay attention to your amp’s class. A proper amplifier will not get hot very quickly.
Provide Proper Ventilation
Move your amp to a location where it gets sufficient free air. Give space at the top, bottom, and sides for unrestricted airflow.
Use an Amp Cooling Fan
If your amp still doesn’t get enough airflow, you should consider getting a cooling fan. A 12V fan is suitable for most amplifiers, and their installation is straightforward.
Use Speakers with the Proper Impedance
If you plan to run low-impedance speakers, invest in amplifiers that can power them.
Repair Blown and Shorted Speakers
Ensure Your Amp Has a Good Ground Connection
Check if the ground wires is connected properly. Fix any cuts or frays in the jumper cable or change the jumper cable if necessary. If this doesn’t solve the issue, find a clean metal spot on the trunk and make a new ground location.
Use Proper Ground and Power Wires
It’s not enough to have a good ground location; you need wires of the proper gauge to supply the correct amount of power. Purchasing a ready-made wiring kit will make the job easier.
Dial Down the Gain and Bass Boost Settings
The best way to get a proper gain is to start the bass boost from zero and adjust slightly to a level you’re happy with. If you hear any distortion or clipping, reduce the bass by 2dB and leave it at that level.
An overheating amp can be annoying. However, you have been shown what causes overheating in amps. We’ve also discussed some solutions, many of which relate to proper connections and judicious usage. Using the above tips, you should be able to easily diagnose and fix an overheating amp.
Is it Normal for an Amplifier to Get Hot?
Yes, it is. The components of an amplifier normally get hot from usage, and you shouldn’t worry if your amp is working perfectly. However, if your amp shuts down or shows any other signs of overheating, check out the overheating solutions above.
Do I Need an Amp Cooling Fan?
Not necessarily. If your amp works well without extra cooling, you need not get a cooling fan. You should consider getting a fan if other solutions do not work or you just want your amp running cooler than it currently does.
Why Does My Sub-Amp Get Too Hot?
Your amp can get too hot for several reasons, so you should perform a thorough check to know the actual cause. Here are some possible causes of an overheating amp: poor ventilation, aggressive gain and bass boost settings, blown speakers in the circuit, low total impedance, overpowered speakers, improper grounding, and poor amp quality.
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.