How do I connect my home theater>cable box>TV? | Tom's Jun 30, 2015If you can't get video through HDMI, try the component video connection from your cable box to your TV. You'll need a 3x RCA cable to hook each one up; happily, they are usually color-coded RED, GREEN, and BLUE. If you can't get audio, try switching How Do You Connect a Home Theater to a Digital Cable Box To connect the cable box to the home theatre using HDMI, simply plug the HDMI cable into the HDMI OUT port on the cable box and into the HDMI IN port on the home theatre system. If the cable box or the home theatre system do not have HDMI ports, choose a different option. Option two is to plug an optical audio cable into both devices.