I just bought a beyerdynamic mmx 300 for my alienware laptop. I plug it into the headset port and it brings up a screen of alienware audio. I put it on stereo and click the microphone button( only button there). Then I went on YouTube and tried to watch a video, I don't get any sound from my speakers or headphones, but when volume mixer it shows sound going to speaker, but not from alienware audio. Please help