I was unable to find an answer to this question, but feel free to link any additional threads I may have missed.
In my car, I have an aftermarket amp, and multiple HAM and public service radios. I would like design a circuit that would allow me to listen to music(source 1) through the stereo as loud as I want, but when audio is detected from one of the radios (Source 2), the music is muted and audio from the radios can be heard. Source 2 will likely need some sort of audio squelch circuit because the some amount of signal may come through the radio speakers even when there is no audio to listen to. My understanding of circuits is very basic and I would like to learn more about this particular subject. I need help understanding how to trigger music muting based on audio from the radios, and the switching the audio.
Ideally, all radios would be connected to some sort of audio mixer through low level headphone or RCA input to 1 output to the audio switching device as source 2. The OEM head unit output (Source 1) to the amp is high level speaker wire. Input to the amp is currently high level speaker wire. The amp can accept low level RCA inputs, but the head unit requires high level output.
Could you please recommend a path to solving this problem? I lack the knowledge at this point of the correct research terms, but I would like to learn enough to design my own circuit.
Thank you very much! Solving this problem would be extremely helpful to me.