How would you fix the issue that you get with headphones where you have to have the wire at a specific angle so that the audio does not sound like it is underwater, or even so the audio plays at all? Or is it not possible without buying new ones?
Depending on what part of the wire you talking about it could be
- the wire is losing it's connection to the speaker
- the wire is broken inside the wire wrapping
in these cases it is possible to fix.
But you have to take apart the headphones and re-attach the wires, apart from that there isn't much you can do to fix the issue.
Try to open the headphones with a sharp tool and replace the whole cable if you can't find the interruption. The most cheap headphones you can not open without damaging so you have to get rid of them.
Something that is very low tech, but that works for me is if you take a rubber band or a piece of tape and use that to hold the cord at a angle. This is by no means permanent, but does extend the life of the headphones.