9 out 10 times this is due to a bad cable or connector, it's common with Sennheiser, especially the 580s. The same thing happened to mine and initially I spent a lot of time messing with the tubes on my headphone amp, but it turned out to be the cable.
If you are using a mini to 1/4 adapter get a new one. If that doesn't help get another cable, you can get replacement cables from Sennheiser or an upgrade from Cardas, headphile, or several other places. I went with an upgraded cable from Cardas and then went one step further with a set of woodies from headphile and I'm really happy with the results.