Hey all

I am looking for some insight by those electronics wizards out there (Modifry? MacGyver? Qube?) who might know a thing or two about how a cellular mute lead works on those aftermarket HU's that possess them. What I want to do is see if there is a way to have my radio mute when my Pocket-PC based Navi system is about to give audible directions. Is there anyway to wire the two together to accomplish this? I know there's not a direct wire solution, but is there some sort of interface that detects when an audio signal is being delivered, and could trigger the radio mute to do its thing?

I have a weird personality quirk that if there is an option afforded me (in this case, an unused mute lead), I want to see if i can exploit it!

Thanks, all...

 

Oh, I guess I should mention that I have an Alpine 7894...

 

Most head units with a MUTE lead (may be called ATT too) require a ground on the wire to activate the function. Of course Honda uses a +12v signal to activate MUTE on the S2000 factory radio, I guess that's their way of being different than the rest of the world.

What you need is something to detect audio output of the NAV and trigger a ground for the mute function on the HU. This is not an easy job unless you have a good bit of electronic design background.

If I were going to do this (and I'm not) I would use an amplified external speaker plugged into the headphone jack so background noises in the car don't activate mute. Or, on second thought, I would build a circuit to interface into the stereo system so NAV sounds not only mute the HU but are amplified by the external stereo amp and come out of the stereo speakers.

 

Thanks Modifry! I had a feeling there would be no easy hack...