solarmaze's profile

Frequent Visitor


11 Messages

Fri, Jun 11, 2021 2:39 AM

No Dolby Digital 5.1 from X1 Box for X1 Apps

My old Comcast box had a TOS output that I had connected to my Receiver in order to get 5.1 Dolby Digital.
My new X1 box "Comcast X1 XG1v4-A 4K Primary TV Box" Does not have a TOS output, only HDMI out.  I 

connect the HDMI out to my TV's HDMI input. My new TV does not "pass" Dolby Digital out of it's TOS 

So I do not get 5.1 to my Receiver... my Receiver is not ARC, so I cannot use HDMI Audio to it. So I 

purchased an HDMI Audio Extractor, and connected it between my X1 Box and my TV.  [X1 Box: HDMI Out] 

>>> "In"  HDMI Audio Extractor  "Out" >>> [to HDMI on TV], AND Extractor has a TOS output that I connect to 

my Receiver. 
Now here is the strange part: Watching a TV channel from the X1 Box, my Receiver shows "Dolby Digital" 

and I get 5.1 audio from my Receiver.
BUT, If I run ANY application built into the X1 Box... Netflix, Prime, Disney Hulu, Vudu, I do not get ANY 

audio to the Receiver. 
It cannot be my extractor, since it works fine on a TV channel.  
Going in the Audio settings on my X1 Box: I only have 2 choices for "HDMI Audio Output" 
1 = "Auto Detect Dolby Digital" - Which if I select - I get NO Audio for a TV channel or an X1 App.
2 = "Expert Setting Dolby Digital" - Which does give me Audio (5.1 DD), But only for a TV Channel... Nothing 

from the same X1 Box if I choose an App from the box! 
Calling Comcast is no help, they just have you power cycle the X1 Box, or they send the X1 Box a reset, 

which has NO effect.  And the Comcast Call Center people have no technical knowledge beyond that.
If only Comcast had a 4K Box with a TOS output, but they do not.


Official Employee


2.8K Messages

2 m ago

Hello, @solarmaze. Thanks for reaching out to us here on the Xfinity Forums for support.


When it comes to 3rd party equipment we are somewhat limited in our ability to support. The fact that Dolby Digital at least works with our channels is a good start. Have you had a chance yet to reach out to the manufacturer of your receiver to see if they are able to offer any further advice when it comes to that type of setup? 



2 Messages

1 m ago

@ComcastTambrey seriously what kind of response is this? Why should the customer reach out the manufacturer of his receiver when the problem is with your X1 box?? Can you at least acknowledge whether the X1 box works with apps like Netflix, ESPN, etc versus only the tv channels ? It sounds to me that the X1 box has audio limitations… I can’t even connect my Bluetooth speaker to the X1 Box and I called/messaged Comcast who were zero help! SMH.  



2 Messages

1 m ago

I need to know whether Comcast’s X1 box I will pass audio through an hdmi extractor so that my PC monitor will display and can play audio using my 3.5m speakers. As this gentleman mentioned above, he’s having issues getting sound using apps within the X1 box, but not when browsing tv channels. 

Comcast, is your box capable of doing this or is it as shitty as Gavin Belson’s hooli signature box? Please advise. 

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