All the Ear Force headphones designed for use with the Xbox and Xbox 360  
connect from the stereo analog audio outputs from the game console:
    AXT - connects from red/white L/R
    X2 - connects from red/white L/R
    X1 - connects from red/white L/R
    XBL - is the exception (only connects via Controller Cable). 
 
Some super-high end aftermarket A/V connection cables for the Xbox 360 do not
supply an analog audio connection at all. Instead, they have RGB component
video RCA plugs and an optical S/PDIF connector for the audio. In other words,
digital audio connection *only*. 

Here's a picture of one popular version: 
   
Connection using X1: 
    Since this type of connector must be used with an external Dolby Digital
    decoder (such as in a home theater receiver), we recommend that you obtain
    a 1/8" stereo female to 1/4" stereo male audio adapter or extension cable 
    and use this to connect the X1 headphone to the Headphone Out jack on your
    home theater receiver. Connect the X1-Xbox "Puck" cable to the Xbox 
    controller and you should be good to go. 

Connection using X2: 
    Since this type of connector must be used with an external Dolby Digital
    decoder (such as in a home theater receiver), we recommend that you obtain
    a 1/4" stereo male to 1/8" stereo male audio interconnect cable and run
    this from the Headphone Out jack on your receiver to the AUDIO INPUT on
    the X2 base unit. Connect the X2-Xbox Controller Cable to the Xbox
    controller and you should be good to go.
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