Sennheiser HD518 audio quality suddenly turning bad

[borowcy]

Hello, I've had Sennheiser HD518 for few months so far. They're working pretty much perfectly, but recently a problem appeared.

The thing is, every few hours the sound quality instantly goes to shit. It feels extremely flat (not sure if that's the correct description).

I fix it by unplugging and plugging the cable to the headphones (it's unpluggable in this model).

I really need help as soon as possible.

Thanks in advance for help.

Perhaps useful information:
-I can replug it from either side (as in, either the cable on headphone end or PC end) to make it work properly
-The 6.35-3.52mm adapter is bent pretty heavily and cracked a bit, I can't connect it to anything else than my PC and keyboard
-Rebooting the PC does not fix the problem
-Disabling the audio device in Windows and enabling it does not fix the problem

 

[ssddx]

1. does it work fine on other devices such as your phone, an mp3 player, someone elses computer, etc?
2. have you tried another cable?

 

[borowcy]

No, I don't have any other cable for my HD518, they're pretty expensive because you can lock them in.

I can't really try using it with other devices, because the adapter is broken ://// I'll try to buy one tommorow.