[junkyspace]

I am trying to build a simple switch to have a single headset (sennheiser) with a TRRS end that will swap between at least two source (desktop vs. laptop). I bought a Sescom switch and them bought a 4P3T switch to replace the original one after I encountered audio issues, but I had the same result. Even with the microphone muted (physically - the microphone mutes at the boom), audio I hear is leaking into the microphone channel. I know how to basically solder, but I am not sure about how to protect against interference (or whatever else is causing it?)

I opted to try to build the switch with a project box and a switch (https://www.amazon.com/gp/product/B07JLX6LX4) where it's very transparent that there is no potential for physical connection between the poles, but I am getting the same issue. Do I need to get shielded cabling (I know nothing about this stuff - I just solder things)?

Thanks!