If you have the Xbox 360 setup with a digital optical cable:
The X3 transmitter does not have an Optical Digital Input. It has an analog
Line In with 3.5mm mini-phone jack (a.k.a. 1/8" mini-phone jack).
If you connect your Xbox 360's Digital Out to a home theater receiver (with
Optical Digital In), you can then connect the receiver's Headphones output
to the Line In on the X3 transmitter. Stereo audio will playback through
the X3 headset.
For Live Chat, connect the Xbox Controller to the X3 using the supplied
X3-Xbox Controller Cable with Mute and Level controls.