Car audio systems can be quite complex, and their problems are often difficult to root out. This is especially true for beginners or inexperienced audio enthusiasts.
In addition to having all the same components of home audio systems, car audio systems are designed to be installed in unforgiving environment and therefore are subjected to vibrations, temperature extremes, rumbles, and other stresses on the road. This makes them prone to failing in different ways as any of the components can stop working unexpectedly.
But, one of the most annoying fails, and what many people dread most is a car stereo cutting out for no apparent reason. Besides being annoying, it’s also a nightmare to diagnose and fix.
A car stereo does not just cut out as there must be an underlying problem. Actually, there can be a multitude of reasons why your car stereo cuts out especially when the volume is turned up.
In this article, we are going to discuss the main reasons why that happens, the possible solutions, and also provide some handy tips to help prevent the problem.
Reasons Car Stereo Cuts Out at High Volume
There are all sorts of reasons as to why a car stereo cuts out when volume in cranked up. To figure out what your specific cause was, below are eight of the most probable causes which you can examine and see if they match your sound system’s current situation.
We recommend going through each section below to help find a fix to your problem.
1. Bass setting too high
If you’re pushing your car stereo to the limit by cranking the bass boost and loudness features all the way up, you’re essentially overloading the receiver’s capabilities.
Loudness and Bass Boost are meant to be used reasonably at low volume levels where it may be necessary to slightly increase bass frequencies in order to provide a fuller, more rich or balanced sound.
By cranking those features up, you’re basically demanding too much power from the head unit. The latter tries to keep up with that, but fails due to the extra power it’s trying to push out.
That said, if your radio keeps cutting out when the volume is increased, the very first thing you need to do is to ensure the bass boost and loudness features are cut down to the bare minimum, or completely turned off.
2. Radio is in protect mode
Some head units are featured with protection circuits, which prevent them from serious damage when something goes wrong, such as when there’s an internal short, when a speaker is blown, when speakers wires are grounding out, when the head unit is overloaded …etc. It’s safe to say that the “protect mode” is basically the electrical engineering version of the COVID-19 lockdown.
To get your receiver out of protect mode, here’s what you need to do :
- Turn the receiver off and disconnect all speaker wires.
- Turn it back on. If it shuts off immediately, it’s highly likely it has an internal short.
- If the head unit doesn’t turn off, connect one speaker at a time.
- If it shuts off after connecting a speaker, there’s a good chance the speaker’s wiring or the speaker itself has a problem
- Replace the faulty wiring.
- Replace the speaker if you have replaced its wiring and the receiver is still going into protection mode.
Furthermore, overloading, or let’s say impedance mismatch is another reason why your car stereo cuts out when you bump up the volume. I mean, if your head unit is presented with a low impedance load that’s beyond its capabilities, it’ll try to keep up with it, and eventually it’ll shut down to protect itself.
3. Shorted speaker wires (speakers wire grounding out)
If your car stereo cuts out intermittently when volume is increased, or when the car is moving, the culprit is most likely a speaker wire that’s been damaged, or a speaker wire that’s loose and is touching metal causing the speaker to short out.
Speaker wires run through the cabin, and connect each speaker to the head unit (or the amplifier).
Short circuits can occur at any point in the signal chain. So, make sure to visually inspect the speaker wires that connect the radio to the speakers. Look for any crimping, kinks, tear, or cuts in the insulation, and fix or replace any speaker wires with visual damage.
If the wires appear in good shape, ensure all of the connections on your speakers are corrosion free, and haven’t come loose to the point where they can create a short.
The downside, however, is that since speaker wires are often routed behind OEM panels and trim pieces, under seats, and beneath the carpet, visually inspecting them isn’t that easy at all. So, depending on your vehicle, it may be easier to check for continuity – using a multimeter – between one end of each wire (at the head unit or amp) and the other end at each speaker.
If you don’t see continuity, that means there is a break or cut somewhere along the wire. On the other hand, if you see continuity to ground, then you’re dealing with a shorted wire.
4. Blown speaker/subwoofer
If any of your speakers is blown, or is grounded to the chassis of the vehicle, your head unit will still try to put power to it. When it does, it “sees” a condition that makes it go into protect mode or shut down. Same thing applies when you have a blown subwoofer.
If none of your speakers is blown, yet the head unit is still cutting out, make sure the speakers are tightly mounted in their mounting holes, and that none of the speakers magnet is touching the door metal.
Generally speaking, it’s pretty easy to tell if a speaker is blown out because when it happens you’ll almost immediately notice that it stops working or no longer sounds normal; distortion, buzzing, and crackling are some indicators of a blown car speaker.
If, for some reason, you couldn’t tell whether a speaker is blown out or not, use a multimeter and check all of your speakers one by one. Disconnect each speaker and check for continuity. If there isn’t any continuity between the speaker terminals, that usually means it’s blown.
In the case of a subwoofer, set the multimeter to measure resistance ohms (Ω), and hook the multimeter’s leads to the subwoofer’s positive and negative terminals to determine whether there’s any electrical resistance in the coil circuit.
Each subwoofer has its own specific ohms reading. So, if the multimeter displays a reading that’s far below expectation or if the reading fluctuates abruptly, the sub’s voice coils are blown.
5. Voltage drop
Voltage drop is another strong causal factor for sound cutting out when volume is turned up. This is especially true if it happens often when bass hits.
I mean, think about it, car amplifiers – especially powerful ones – are power hungry and crave electrical current. Luckily, most cars produce more of that than they need, which is the reason why a car can keep its battery fully charged even with all the accessories turned on (headlights, oil pump, windshield wipers, car radio, speakers…etc)
The bad news is that your alternator isn’t an infinite source of power. There comes a point where it can’t keep up with the elevated demand for electrical current, and that point is when you have a power hungry stereo system and you crank the volume up, or play heavy bass track. This will make the amp go into protect mode or actually shut off. It may also make stereo cut out due to there not being enough power supply.
To make sure the voltage drop is what’s causing your car stereo to cut out, you’ll need to use a multimeter to check your voltage at the amplifier while the system is playing. If the voltage is dipping below 12 volts, then a heavy-duty alternator and a strong battery might be required to maintain a stable supply of power. This is especially true when you have a big subwoofer driven by a powerful amplifier.
6. Starved amplifier (insufficient power supply)
Amp starvation or insufficient power supply goes hand in hand with voltage drop. This is because for an amp to operate efficiently, its power and ground wires must be large enough to accommodate its demand for electrical current.
That said, if you’re using an inadequate wiring kit that is too thin or made of low quality materials, the amp will starve the power supply it needs to perform efficiently, thus limiting its performance.
An amplifier that’s being starved will have a hard time trying to drive the speakers/subs. Not only that, but it may also experience thermal shutdown, blow its fuse, or go into protect mode when bass hits hard, making the sound cut out.
That said, make sure you use an adequate wiring kit for optimal amp performance. As a general recommendation, use the chart below as a quick reference in determining the appropriate wire gauge for your amp.
|Wire Gauge Size||Total Amplifier RMS Wattage|
|0/1 AWG||1000+ Watts|
|4 AWG||400-1000 Watts|
|8 AWG||200-400 Watts|
|10 AWG||100-200 Watts|
7. Bad/loose ground
Improper amp grounding can cause a wide variety of issues in a car audio system including but not limited to: clipping, whining noise, blowing fuses, weak output, overheating, or even fire.
Most of the issues caused by a bad ground go hand in hand. I mean, if your amplifier is overheating, it’s also likely to be overloaded (impedance mismatch), and if it’s clipping, chances are that the gain is set too high…etc.
It goes without saying that when installing an amplifier in your car, the ground wire can make or break your sound system. This is because grounding completes the electrical circuit powering the amplifier. And for this reason, you need to make sure your amp is properly grounded to the vehicle’s chassis.
That said, ensure the ground for your amp is secured tightly and that it’s directed to a bare metal area of the car chassis that’s sanded down and scraped clean of any paint or primer, preferably within eighteen inches of the amp’s mounting location.
Essentially, the same thing also applies to head units. I mean, the head unit must be grounded to the chassis just like you would ground your amp to the chassis.
So, if you’re installing a an aftermarket receiver, find a piece of the body or steel framing in the dash behind the head unit, sand down any paint or rust until you see the shiny metal and ground your head unit to that.
8. Impedance mismatch
If your head unit or amplifier is presented with an impedance load that exceeds its capabilities, it will try to draw more current than its power supply is designed to deliver, making it go into protect mode or shut off.
One of the most common impedance mismatch is when you hook up 1-ohm subwoofer up to a 4-ohm amplifier or when you wire a couple of 4 ohms speakers in parallel and end up with a 2 ohm load, then bridging a 4 ohm amp to that load.
An amplifier or a head unit that’s overtaxed because of impedance mismatch might play for a short period of time and then shut off, or it might keep working when the volume is down, but shuts off immediately as soon as the volume goes up.
So, always make sure your speakers’ impedance or their overall impedance load when wired together is within the capability of your amplifier.
If everything checks out okay, and you’ve ruled out all the things that could make your car stereo cut out at high volume, you need to get the battery and the alternator checked out. You might also want to consider upgrading your electrical system if the problem persists.