Are you saying that by putting a hdmi cable in your pc and xbox you want to be able to use your G35 as a headset on the xbox? This is not possible and I don't believe the G35 will work with a xbox at all. You may find a way to hack around it and get it to work if you dig through some hardware forums or something but probably not. Hmmm or are you saying hook your PC up to your tv to recieve the audio than transfer to the G35?