Sam, I would have thought the same thing. When I soldered my speaker out wires to the speaker inside my garmin, I used the pigtail I cut off from a female 3.5mm extention, not a standard jack that cuts off the internal speaker if something is plugged in. So, my internal speaker on the garmin is always on. I can confirm that there is no noticiable delay between Garmin speaker and the audio from the car stereo when my TR7 does trigger the mute.

I wonder about the VOX unit though, as what if my wife and I are talking - we still do that after 16 years or what about the stereo being on?

I am interested in WhiteXKR's idea that he can design something that will work. I would think that what I am trying to do would be common. But even finding GPS units that come with bluetooth A2DP is proving difficult (which would be the best solution I guess). I can't find any new ones that have it though, except for those in the $500 range. I just bought my 2360 about 6 months ago with free liftime maps...I don't want to buy a used unit that has A2DP but not the lifetime maps just to make this work. I hope others are interested, we'll see.

 

It will be interesting to see, The relay in the unit itself is probably less than 10ms, which should not itself be much of an issue.

Does the Garmin have an option for a tone before it starts talking?

Also, I think you may have to attenuate the input with a couple of resistors or a pot, since the unit is designed for a low level microphone input.

 

No it doesn't tone before talking. I have been searching garmin "hidden features" for this, as the older one's did. I was hoping this was a little known feature available, but I can't find anything. It would likely resolve nearly all of my issues. Also, I purchased a Garmin FMI cable to hardwire my garmin to car power. This cable aslo has a data cable to connect the gps to serial ports for tracking devices. I started looking at this hoping that maybe there was some usefulness for this application, didn't find anything.

 

That would not be an issue. You don't want to use the microphone that comes with the VOX unit. You want to hard-wire the Garmin speaker directly to the microphone input on the VOX unit. That way the VOX unit will only "hear" what's coming from the Garmin speaker. And like WhiteXKR said, put a resistor in series to attenuate the speaker volume to a voltage level that's closer to the microphone output voltage.

 

And.... if your wife ever does accuse you of not listening to her, you can still hook up the microphone and prove to her that what she says is so important you set up the radio to automatically mute when she speaks.

 

That IS funny - she would really appreciate it - HA!

You know, I feel kinda dumb regarding my post about the mic, because before I wrote it, I thought about connecting the audio direct to the mic input, but I posted anyways without thinking.

Sam, really curious how it works out for you, seems like it should work well. If you decide not to purchase, let me know and I will. I just figured I would wait to hear of your experience since you mentioned you were going to buy one.

Thanks guys!

 

Just bought it. Hopefully it will be here one day next week.

 

Well, it didn't work. It's a kit, which made it easy to adjust the input sensitivity. The circuit itself is expecting to see microvolts from the microphone, but I had it hooked straight to the Garmin speaker. I added some resistors in series with the mic input, plus a potentiometer to adjust it, but even after adjusting it there was still too much of a delay the first bit of the word always gets clipped. I think it has to do with the amp as much as the VOX module. It just seems like the amp can't switch over to the GPS quickly enough.

 

Thats too bad...nice try. I guess the factory nav. mute switches a bit before talking starts to compensate for the delay.