The cord on my headphones went kaput. I tried to fix it, but the wires inside the cord were stranded and coated with enamel—almost impossible to deal with. Eventually, I gave up on any prospect of fixing the existing cord, and went to scalp a cord from any old headphones I had laying around. I only managed to find one pair of headphones with a usable cord, while the headphones I was repairing had split cords for each ear... Desperate, I cobbled together what I now present you with:
The wire you see bridging the two speakers is single 24-gauge conductor from some CAT5 (cut into two pieces, of course.) The resulting impendence is a little uneven, at 30.4Ω for the left speaker and 32.5Ω for the right, but it's usable and the sound quality is surprisingly good.