Microphone Replacement

[rauld]

Hi, I have a car stereo that has a Bluetooth phone link option, unfortunately the mic on the stereo is terrible and people really struggle to hear me. The stereo does not have a external mic option. The microphone itself is just surface mounted to the board and is tiny, 3mm diameter. My question is, can I desolder it and run some wires to something like a lapel mic that sit's on the dash? Isn't there some issue with cord length and mics? If so, wild the best bet be find a better quality mic maybe from an old cell phone and solder that in?

Thanks for any help, Rauld

 

[(*steve*)]

The main issue would be that your new mic is compatible with the circuit the old mic is connected to. After that, the use of shielded cable (that is standard on microphones) should be sufficient.

 

[rauld]

Ok, the mic on the right is the one I pulled off the board (which lost a pin in the process) and the one on the left is from an old cell phone. I don'y know what kind of mics they are but they look the same except the left one is missing the "+" sign. I have scavenged an RCA cable and soldered it to the board. Tomorrow after work I will solder the new mic onto the other end and see if it works! Two questions though, is there a way to test which lead form the mic is positive? And, what kind of mics are these?

Thanks, Rauld

 

[73's de Edd]

Sir rauld . . . . .

Both are being Electret microphones . . . . . .and they are superb little units . . .but your solution may just be in getting it on up MUCH closer to your mouth.
But it needs a shielded wire run, and the polarity for both units are being as per the one that is shown.

ELECRET INFO:
https://en.wikipedia.org/wiki/Electret_microphone

The electret cartridges supply voltage originates at your on board circuitry and you would be able to read it at one of the present wires going into the element.
Back at the radio /bluetooth circuitry the return amplified audio is stripped off with an electrolytic to be fed to the systems audio line.
(Shown in the mini schematic)

73's de Edd
.....

 

[rauld]

It works! Thanks for all the help and here are a couple of pics. The red circle in the car pic is where the mic was and the green is where I moved it to.
Thanks! Rauld