Audi S4 Audio System Goes Completely Silent

Having dealt with a similar complete audio failure in my 2006 A4, I might be able to help based on my experience level with car audio systems. The symptoms match exactly what happened with my car speakers, complete silence despite the head unit appearing to function normally. After checking the auxiliary input and various audio sources, I discovered the issue wasnt source-related. The workshop found that the bass speaker had failed catastrophically, causing a short in the amplifier circuit which triggered a safety shutdown of the entire sound system. The repair involved replacing the defective speaker and resetting the amplifier circuit. Total cost was 280 Euro, but it restored perfect sound quality with no sound distortion. To provide more specific guidance, could you share: Any warning signs before the total failure? Whether the system makes any noise (static/popping) when switching sources? If theres a separate amplifier in your setup? Whether the factory sound system is still original? These details would help determine if youre facing the same root cause or possibly a different issue with similar symptoms.

Thanks for sharing your experience. My S4 has 106372 KM and had its last service 3 months ago. I heard no warning signs before the failure, it was working perfectly one day and completely dead the next. The sound system is completely original, and theres zero noise or static when switching between USB audio or any other source. Even at maximum volume control settings, theres absolute silence. Not sure about the amplifier setup, but I can check under the rear deck. Interesting point about the bass speaker possibly causing an amp shutdown, will have that checked.

Based on your additional details, this sounds even more similar to what I experienced. Since both our cars share similar audio architecture, the complete radio silence without any warning points strongly to the amp protection circuit. When my A4s system failed, it also went from perfect operation to total silence overnight. The lack of static or interference when switching audio sources actually reinforces the amplifier shutdown theory rather than pointing to Bluetooth issues or auxiliary input problems. The workshop found that testing the amplifier outputs was key to diagnosis. In my case, the bass speaker short triggered the protection mode, but your symptoms could also indicate a failed amp itself. The fact your system shows no signs of life even at maximum volume suggests the issue is after the head unit in the audio chain. A few checks you can try: Look for moisture damage near the amp, Test speaker continuity if you have access, Check amp power connections, Verify if a basic system reset restores sound If these dont help, professional diagnosis would be worth the cost to avoid replacing parts unnecessarily, just like in my repair experience. The fix might be similar to my 280 Euro repair, depending on whether its the amp or speaker causing the shutdown.

Good points about the amp protection circuit. Will try these checks and have my regular shop take a look. After discussing this, I feel better about not out of nowhere swapping parts since the symptoms match your situation so closely. The sudden failure without any sound distortion or warning signs definitely suggests a safety shutdown like you experienced. Will report back after checking the amplifier outputs and especially that bass speaker connection. Hoping its just the speaker causing the amp shutdown and not a more expensive amplifier replacement. At least now I have a clear starting point for diagnosis rather than being completely in the dark about why my sound system went silent.