Why does my car amplifier switch off when I play loudly?

If the amplifier works at low volume but switches off when you play louder, this is often because the load increases and one of its protection functions is activated.

The problem may be caused by voltage drop, overheating or speaker impedance that is too low, for example.

Common causes

1. Supply voltage too low
The amplifier’s current consumption increases when you turn up the volume.

If the battery, alternator or wiring cannot supply enough current, the voltage may drop enough to make the amplifier switch off.

2. Impedance too low
If the speakers or subwoofer are wired to an impedance lower than the amplifier can handle, the amplifier may be overloaded.

This is particularly important when several subwoofers or dual voice coils are wired together.

3. Overheating
If the amplifier gets too hot, its thermal protection may activate.

Check that it has sufficient ventilation and is not installed where heat is trapped.

4. Poor ground connection
Loose connections, undersized cables or poor grounding can cause significant voltage drops as the load increases.

5. Incorrect settings
Excessive gain or incorrect crossover settings can contribute to distortion and overload.

How do I troubleshoot the problem?
First check whether the amplifier’s protect indicator comes on when the sound disappears.

Then measure the supply voltage at the amplifier’s terminals as the load increases. Also check the ground point, cable cross-sectional area and speaker impedance.

If the amplifier gets very hot, let it cool before continuing troubleshooting.

Do not keep playing at high volume if the amplifier repeatedly switches off.

Contact our customer service team or visit one of our stores if you need help identifying the cause.