After much head scratching I finally found a <$2 solution to the useless 0.5m cord that came with my AKG K450:
Firstly, it's useful as an extension so the short cord is now extended to about 1.2m. Secondly it even has a mic so if I wanted to I could make calls on it. It puts the mic sort of around your mid-section though so fortunately it comes with a clip built-in so you can move the mic up when you do have a call or want to make a voice note or something.
All K450 owners: buy buy buy!