Why Does My Car Stereo Cut Out at High Volume?

This question is one of the most common questions we get from DIY installers around the world. You turn your radio up to a high listening volume and the audio shuts off or the entire radio shuts off in its entirety.

Before we answer this question please be mindful of the type of audio set up that you have in your car, boat or bike. Meaning, the more complex your audio system is the more problems that can occur. Think about any items like amplifiers, DSP’s, Equalizers and other things that alter the audio or amplify it.

Why does my car stereo cut out at high volume

Overall Audio Shutting off at High Volumes

Bad Ground

The main cause for audio cut outs or total power loss issues in audio systems that we have diagnosed have to do with an improperly performed ground. This could be in/at a number of different locations in the vehicle.

In order to find a total audio loss issue the first place you should look is at the audio source itself.

Bad Connection to Power

You might have a bad connection to power at your amplifier, stereo or at the battery where you connected your power line for your amplifier.

Blown Speaker

you might notice distortion or static coming from a particular speaker in your car. If that speaker is blown or its connections weren’t done correctly you will cause a short. Your stereo and/or amplifier see a blown speaker or a bad connection to a speaker as a random increase in resistance.

An increase in resistance in this situation is generally a pretty high increase and the amp and/or stereo cannot properly power it.

The signal from the amp or stereo need to go somewhere regardless of the speaker fault. This means it will take the signal that should be going to 4 speakers and send it to the working speakers. This will also over power those speakers generally.

Impedance of a speaker in respects to the audio source

Impedance or resistance of a speaker is important to note when installing an amp and a stereo. Your stereo will tell you the resistance that your system should measure out to in order for it to work properly.

For example, if your amplifier or stereo’s instruction recommend a 4ohm stable set up and you wire the system too far under or too far over that spec you can damage your components and/or cause the system audio to cut out.

4 channel or 5 channel amplifier not wired properly

When an amplifier isn’t able to properly do its job it will cause problems for every speaker it is connected to. For example, if you have a 5 channel amplifier (4 speakers, 1 subwoofer) that has a bad ground or power connection all speakers will cut out.

The same could be said for a 4 channel amplified system.

The hardest issue to track down would be with the speakers themselves. When a system is amplified you have to consider the audio source (radio) and anything that alters the signal (amplifier).

Over powered system

This issue usually comes in the form of an amplifier being rated at a higher RMS rating than the speakers are equipped to handle. Assuming your vehicles battery is healthy and the wiring along with your audio source are properly charged and powered your amplifier should match your speakers power if you purchased the proper equipment.

For example, if your amplifier says it supports 100 watts RMS and you have 4 speakers each speaker should be rated at about 25 watts RMS. Four speakers rated at 25 watts RMS ran in parallel should add up to 100 watts RMS.

Subwoofer Cutting out at High Volumes

This section will discuss Subwoofer audio cut outs. These issues have to do with the amplifiers power, the signal to the subwoofer or the subwoofer itself.

Subwoofer amp not properly wired

When the amplifier responsible for powering your subwoofer(s) is not properly wired you can have impedance issues. This happens when your amplifier sees a higher or lower resistance coming from your speakers.

Lets say you wire up a subwoofer and one of the speaker wires are left loosely attached to the subwoofer terminal. While that sub might work at very low volumes, it will cut out at higher volumes.

The reason this happens is similar to what was discussed above in the “over all audio shutting down at high volumes” area. The amplifier sees a large amount of resistance at that speaker and cannot create enough amperage to power a load with that amount of resistance.

Another issue could be that the power or ground wires are not connected properly. The is known as a voltage drop. You can spot this pretty easily by testing the battery voltage at the battery and then at the amplifier. If you notice that the voltage at the battery is significantly higher than the voltage at the amplifier then the issue is in the connection to that battery or in the wiring.

Subwoofer not wired properly

This has to do with the subwoofer wiring itself. You’ll find that the speakers are connected to the amp in a way that increases resistance or lowers it to levels that aren’t healthy for the sub and/or the amplifier.

Wiring to Amplifier not big enough

Often times youll find that the power wires responsible for powering the amplifier are a lot smaller than what the amplifier needs. This restricts current flow from the battery and creates a voltage drop. As you turn the volume up your subwoofer amplifier wont have enough power from your battery to support the signal increase to your subwoofer. This will cause a subwoofer audio cut off.