If that happens yearly and your headphones aren't crappy quality, that means you are rough with them, even if you're not aware of it. (I tend to get the same problem eventually, and at least in my case it's entirely because I'm too rough with the cable and bending it in unintended ways since I've got my phone in my pocket. It might feel natural for us to place that level of strain on our cables, but they usually aren't made for it so we're actively damaging them by doing so.)

Also, unless you're using quiet headphones that need the volume on full blast to get a reasonable level, do yourself a favor and turn it down a bit. Listening to pretty much any music at full volume for extended periods will give you permanent hearing damage eventually, let alone something inherently loud like Metal. If you love music enough to listen to it this much, you really don't want to do that to yourself. You will permanently reduce your quality of life, and it will be entirely your own fault. That's not fun to live with.

Edit: and btw I love the HD25 for Metal specifically. They're the best headphones I've had for the genre, whether it's heavier stuff with intense bass like Meshuggah or rockier, gritty stuff like Motörhead's Ace of Spades album.