DIY Car Speaker Phone with CB Mic

A project I've been trying to do for the longest time is to build a home made speaker phone for my car. There used to be a car phone in it from the pre-cell phone ages and its always sparked my imagination. Basically, from my cell phone's 2.5mm jack to a speaker and to a mic. Now, I have a CB Radio in my Cruiser and it has a built in PA. So what ever I say will come out a 3.5mm jack, very convient for the input for this project. However, I'm a dummy when it comes to speakers. I would have to build a small little loud speaker that would project the sound from my phone. I took apart a headset, so I have the plug for the headset. Now what I don't know is how the wires are arranged in the headset wire and what's the best way to built that speaker from a 2.5mm jack output. The input isn't much of a problem, just gotta figure out which wire in the headset wire is the input... probably red. I'm not much of a electrical guy and I don't currently own a soldering iron. I just have 180w welder.

abadfart7 years ago
cobra now has a cb with blue tooth built in
LasVegas10 years ago
I've already done something very similar to this. My previous car had a stereo that had a 1/16" jack on the front for an AUX input... I tore apart a broken headset for the microphone and attached a 1/16" plug onto the end of the mic's support wire. The mic was connected to the white and shield wire of a cut 2.5mm cable. The black and shield of the 2.5mm cable was then connected to the tip and both rings of the 1/16th plug. The result would plug right into the jack allowing me to adjust the position of the mic and plug the 2.5mm plug into the cell phone (in the ash tray). I did have to press the AUX button when I heard the cell phone, but with the cell set to auto-answer, this was the only step needed to use it. When the call was over, I'd just press the AUX button again to return to the radio or CD. My wife is in Minnesota right now with the camera, so I can't send you a photo, but I hope I described it well enough for you. Most car stereos have at least an AUX wire in the back. You could connect your CB's PA output to that and switch in the same manner. If that's not available to you, just put a small speaker in a wooden box and connect that to the PA port.
Red Beard (author) 10 years ago
it is a little confusing.. let me try to lay it out.
                               [input/mic] ---- CB Output (3.5mm I can get adaptor)Cell Phone (2.5mm Jack) ()---{                               [output/speaker] ----- homemade loud speaker

That's what I want to do. Basically, what's the best way to get the best results. The CB Output is real good I believe, no echo and very loud.

Sort of helps. I feel honored you took the time to tear apart you headphones. But I'm only looking for a mono speaker that I can hear in my Land Cruiser.
its a lion10 years ago
i dont quite follow what you are asking. after reading it again it makes a little bit more sense, but i still dont quite follow it. you have a headphone (or similar type of something) out on the cb radio? and you want to run a cable from it to your speaker? and you want to know how the wires run to the speakers? if so, the red wire runs to the right speaker and the black wire runs to the left. the ground wire will connect to both of them. at least thats how it goes in mine. i took them apart just for you, feel honored :) if im way off then sorry i couldnt help. but i did have fun taking the headphones apart.