Well the SoundCard that I am using is my headset so I will see the graphics drivers.
Just cause your soundcard's built into your headset, doesn't mean it doesn't use drivers. So check Sennhieser to see if there's an update. Also, what's this Turtle-Beach sound-device you have installed? Is that related to your headset as well? If it's a built-in sound device that you're not using for anything you should uninstall or disable it.
I've heard bad things about external USB soundcards in relation to game-performance as well, but just anecdotally.