Does anyone here know anything about wiring and electronics? Especially that related to audio signals? I'm toying with an idea that seems fairly simple in concept and I'd like to know if it's way over my head to try to figure out how to do it myself since I don't imagine it'd be easy to find it anywhere.

Basically, I'm planning to replace the flip-out ashtray in my jeep with a large custom switch panel in anticipation of future toys that I'm planning (anticipate some pictures this christmas break or next summer!). In my jeep, I have a few different audio sources that, due to the immense road noise generated while driving, I have trouble hearing frequently. I have a CB radio, a scanner, maybe soon a PA system (if i feel like wasting some money), and sometimes an FRS radio or laptop or other random thing. I was hoping there would be some way to put in 2-3 input 1/8" mini mono jacks, combine their inputs, amplify it some reasonable amount with a dial for volume control, and have it come out a single output jack which I could plug the external speaker into.

It doesn't seem exceptionally complicated, but then again, I have zero knowledge of electronics beyond wiring up auxiliary lights. Anyone know enough to tell me to give it up? Give up my dream?

You want to tie all the inputs, in parallel, to a single point, with say, 10k ohm resistors in between. Check out this page. From there, you could either tie it into your car's stereo, or if you want it separate, use a small amp like the Sonic T-Amp (fits in your palm) and run it off your car's electrical system.

Ah, thank you! Exactly what I was looking for. You'd think after all the googling I'd done I would have tried the word mixer. I knew just wiring them together was not a good idea. I might look for a bit more custom amplifier if I can figure that part out, though, space is at a premium and even if the amp is small, i want it IN my console with a readily accessible volume knob on the panel, but I'm pretty sure there's stuff about audio amps all over the internet so I'm sure I can find a way to do that.

Anyway, thanks!

You can hide the amp and expose a volume control on the front panel. Get a good stereo, logarithmic tapered audio pot like the Alps RK097 which you can find at Tangent's Parts Shop (he sells his PCBs and related parts for DIY audio, a reliable seller). Wire it inline with the signal that will go into the amp, and just keep the volume on the amp in the highest position (or whatever position you find gets you a good range of control with the new pot).

Great idea, I think that'll work perfectly. As long as I can stuff it back in there, which looks like it won't be a problem, I think this will work excellently. Thanks!

hmmm interesting I may have to do something like that too

this is pure win