We're want to run some headphone & mic cable through the wall to a wall plate in the next room. What type of cable is best for the headphone signal (post headphone amp)?
One way I've done it was to get heavy duty or premium head phone extension cables and run through the wall. Marker-tec catalogue sells wire for this on a spool, you may have to buy a 300-500ft spool though, they sell premium grades of wire/different brands.
You let the sales person know what your doing, they will make recomendations.
It will be a 3 conductor wire.