The idea that’s swimming around in my head is to make a mic set up like V-MODA boom mic, but will work with any pair of headphones you have, and I know that the mod mic is a thing, but I’m trying to go for a single cable solution. Is there a reason that this isn’t a thing that’ll work, are there any suggested parts, has someone done this before and I’ve just missed it?
You would need a 4-conductor + Ground cable for this. LiYCY-type cable should work for this.
And even then, crosstalk from the headphone-out to the mic-in may be an issue.
The “easy” part is the mechanical side of this.
Electret mic-capsule, arm (carbon fiber tube?) and some connector parts (bent metal, wood, 3D-print, etc.).
The difficult part is to do with the electronics as you need to avoid passing the bias-voltage from the microphone jack to the signal outs on the headphone jack.
AFAIK, Mic-jack pinout is like this:
|Ring||Bias Voltage||to microphone|
|Sleeve||Ground||Or shield, not super sure about its role in this|
Headphone jack pinout:
Concerning circuit setup, I would just point you at this thread on L1T:
The alteration in your case is that you don’t have an external mic-preamp, so no need to do any Op-Amp related shenanigans.
headphones have quite a few different connections. in order to make a universal, you would need the end to accept a lot of different connections that could be swapped out. something along the lines of what hart audio cables does, but in reverse(he has an adapter on the amp side)
The three common ones are 2.5mm, 3.5mm and miniXLR.
Easiest way would be to have a 3.5mm TRS socket and using short adapter cables.
Question then is how to mount the device to a headphone.
vmoda boom mic style, have the mic come off of the cord. shrink wrap + electrical tape will make anything very stiff.
edit: or resin coated
edit2: shrink wrap + resin coat would most likely eliminate cross talk as well.
The best way is to have a shield on the aggressor conductor, or a ground-trace between signals.