Hey, Max! I don't have a jack that works in the back of my Comcast box. (I don't have digital, only basic. ...maybe, that's why?) Anyway, the headphone jack works just great with my 5.1 system. I can actually make out the words people are saying on my Seiki tv, now. I really hope Seiki will work on that problem in future models. I've heard it is a common problem in the smaller size flat screens, though. I've, also, heard that smaller screens are becoming a thing of the past, anyway. I don't have a big space so a larger screen would be overkill for me. Anyway, I am a very happy camper, now. Thank you, again, for all of your help.