Does your cable box have HDMI ports on the back? If so, you could look into getting an HDMI splitter/adapter. If you go to our accessories page, the first option is an HDMI splitter/adapter that we would suggest using. Below is the link to our accessories page:
Note: The HDMI splitter/adapter is not a Sling Media product. You do not have to use this brand of HDMI splitter. There are other companies of HDMI adapters that will work.
Hope this helps!