Hi,
The kids are occasionally breaking their mp3 earphone wires due to fatigue/catching and I repair them when I can. The modern ones have colour coded enamelled wire and are both fine and flexible. I generally fix them with some wire and heatshrink and try to rebuild starin reliefs with heatshrink too. Lifetime of a repair is not real good and they don't look 'cool'. Many of these earphones have appaling strain relief and allow tiny bend radii to occur.
I'm interested if anyone has come up with good solid repair methods and materials for the job which they would like to share. Maybe there is even a source of this wire?