Questions on Creating a Custom Combo Headphone/Mic Cable
I recently decided to take on a new DIY project, which is modding my existing headphones (Sony MDR 7506) and my ModMic to combine into a single detachable cable to make it much easier to manage at my computer. Last night I modded the 7506s and their stock cable to be detachable, which thankfully worked out great! The main concern I have now is how to properly combine the headphone cable with the ModMic cable, and I’m having some difficulty finding all the info I need online regarding the subject.
I’ve purchased Mogami W2893 quad mic cable (4 wire + shield) for the project. Originally I thought that both were stereo sources and I was going to run two separate cables for both devices and sleeve them together. However after taking apart the ModMic last night, I realized that it’s in fact a mono mic wired to a stereo jack. It didn’t make much sense to me to add significant bulk to the cable when I may actually be able to combine both into one, making the cable literally half the weight it was going to be before. It was when I started looking up information on combining these cables that I started having trouble, specifically when to use shield as ground, or if I could share a common ground between the two devices. From my understanding it should work similarly to a TRRS cable.
If I were to combine these cables, what would be the best way to wire them? I’ve seen many stereo instrument cables use the shielding as ground. Would I be able to use 2 of the wires for L/R headphone signals, the shielding for headphone ground, and the remaining 2 cables for mic signal and ground? Or would there be a better way to do this (my other idea was to use a common ground between the two devices but I’m not sure if this is a good idea or not). My thought would be to wire it similarly to the way that regular TRRS cables are wired, however I’m not totally knowledgeable in that either, particularly when to solder the shield and ground together if at all. Would I combine the ground wires of the headphones and mic into one, then solder those to the shield as well so they have a common ground and shield?
Thanks for reading! Any help would be really appreciated