You cannot connect the cameras to your TV to play a 3D file.  You will not have a 3D file until you convert the two 2D files recorded by each camera into a single GoPro 3D media file.  So, you will not be able to playback in 3D directly off the camera.  You will need to use GoPro Studio in order to create a 3D file from the files you recorded using the 3D HERO System or Dual HERO System.  Once you have a converted file on your computer, you can playback on a TV from your computer, or export the file for playback using a different device.