Seat Altea audio system failure

That sounds frustrating! I had a similar "radio silence" issue with my old Renault Megane. The entire audio system just quit. Have you checked the basic stuff like fuses? Also, does it affect all audio sources? USB audio, radio, everything?

Thanks! Yes, I checked the fuses, they seem fine. And yes, it's all audio sources. Radio silence across the board. No sound from USB audio either. Even the parking sensor beeps are gone. Could a defective speaker really cause everything to go silent? Even the volume control on the dashboard doesn't seem to do anything. And what about Bluetooth issue? Could it be related?

Yeah, a completely dead speaker could potentially cause the whole system to shut down, especially if it's shorted internally. Some systems are designed to protect themselves from damage like that. And if the parking sensor uses the same speakers, that would explain why you're not hearing those either. As for the Bluetooth issue, it's hard to say for sure without knowing the exact wiring and system design, but it's possible they are related. However, since everything is gone, it's unlikely to be a software problem. I'd say it's worth getting it checked out by a professional at a workshop. That's what I did with my Megane, and it turned out to be a similar speaker issue. They were able to diagnose it quickly and replace the faulty speaker.

You were spot on! Took it to a workshop and they confirmed it was indeed a defective bass speaker, just as you suspected. Got it replaced for 280€. Thanks a bunch for your help!