Question Anyone got an LG B9/C9, Xbox One X and using ARC to pass audio back to an amp?

ReflexReact

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I'm having significant audio delay issues with my set up - and my internet research has led me to the (hopefully wrong) conclusion that LG's latest and greatest TV is a bit crap!

Basically, my set up is Xbox One X > C9 > Denon Amp via ARC.

What I want to achieve is:
  1. 5.1 audio passback via ARC (compressed or uncompressed, I cannot tell the difference)
  2. take advantage of the TV's features such as VRR which I get from connecting the console directly to the TV
How I've set things up:
  • I have set the TV Audio advanced settings to "Bitstream" on HDMI port 3 (the one the Xbox is plugged into).
  • I have set the Xbox's HDMI audio output to "Bitstream" and then setting the Bitstream format to "DTS Digital Surround". I have also tried "Dolby Digital" here.

In all cases, I have a 300-600ms audio lag. I've done some Googling and found others reporting similar issues, suggesting it's the LG TV's which are struggling to decode and send the signal to the amp without introducing the delay. My questions:
  • Why would the TV be doing ANYTHING with the audio at all? Can't it just pass it through?
  • Do you have an LG B9/C9 and an Xbox one X, passing the audio back to your amp via ARC without audio lag? If so, how is everything set up?
  • If ultimately this is the fault of the TV and there is no solution, could I technically run an optical cable from the Xbox to the amp just for audio? (This is not my preference as it'll be a pain having to switch the amp manually every time, but I guess if it's my only option...)
  • I've been told buying an amp with eARC will solve this problem as it'll let me pass back PCM (lossless, uncompressed) audio from the TV to the Amp. Is anyone certain of this as a fix? Would it make more sense to wait for amps to support VRR HDMI2.1 passthrough etc? I plan to buy next gen on release date!
Thank you SO much for all your help, I do appreciate it!
 
I'm having significant audio delay issues with my set up - and my internet research has led me to the (hopefully wrong) conclusion that LG's latest and greatest TV is a bit crap!

Basically, my set up is Xbox One X > C9 > Denon Amp via ARC.

What I want to achieve is:
  1. 5.1 audio passback via ARC (compressed or uncompressed, I cannot tell the difference)
  2. take advantage of the TV's features such as VRR which I get from connecting the console directly to the TV
How I've set things up:
  • I have set the TV Audio advanced settings to "Bitstream" on HDMI port 3 (the one the Xbox is plugged into).
  • I have set the Xbox's HDMI audio output to "Bitstream" and then setting the Bitstream format to "DTS Digital Surround". I have also tried "Dolby Digital" here.

In all cases, I have a 300-600ms audio lag. I've done some Googling and found others reporting similar issues, suggesting it's the LG TV's which are struggling to decode and send the signal to the amp without introducing the delay. My questions:
  • Why would the TV be doing ANYTHING with the audio at all? Can't it just pass it through?
  • Do you have an LG B9/C9 and an Xbox one X, passing the audio back to your amp via ARC without audio lag? If so, how is everything set up?
  • If ultimately this is the fault of the TV and there is no solution, could I technically run an optical cable from the Xbox to the amp just for audio? (This is not my preference as it'll be a pain having to switch the amp manually every time, but I guess if it's my only option...)
  • I've been told buying an amp with eARC will solve this problem as it'll let me pass back PCM (lossless, uncompressed) audio from the TV to the Amp. Is anyone certain of this as a fix? Would it make more sense to wait for amps to support VRR HDMI2.1 passthrough etc? I plan to buy next gen on release date!
Thank you SO much for all your help, I do appreciate it!
I have no “lag”, but sound cutting out regularly for a second or two. I bought a new 2.1 cable and it’s much better. Using Netflix or Prime Video, the sound cuts out briefly about once every 15 minutes now.
 
Last edited:
Man I've got it somewhat better by enabling passthrough on the HDMI settings on the TV, however I still have a 200-400ms lag when set to Dolby DTS. With Dolby Digital it goes up to 600-800ms and then with Dolby Atmos I am looking at over a seconds audio lag! Simply terrible from the LG C9 if I'm honest. I guess I'll need to start looking into new eARC amps and cross my fingers that it solves the issue (I presume it will as It'll support PCM, right?)
 
  • If ultimately this is the fault of the TV and there is no solution, could I technically run an optical cable from the Xbox to the amp just for audio? (This is not my preference as it'll be a pain having to switch the amp manually every time, but I guess if it's my only option...)
How about running the optical from your TV to the AVR then you can avoid any manual switching on the amp.
 
It should be fairly easy to try and there's nothing to lose unless you need to buy an optical cable. At least it would narrow down the problem (or not) to the ARC feature.
 
It's not a direct comparison but I recabled the Xbox One direct to HDMI1 on LG B8 TV and passed 5.1 sound to Onkyo TX-NR686 via ARC. Gunshots in Battlefield were slightly delayed but not annoyingly so and nothing on the scale you suffer from. Watching streamed movie dialogue might be a different story though.
 
I've hit similar with the B7, I have a Denon x3600h and haven't tried running it through that yet instead of going direct to the TV and sending audio back with eARC, my understanding is the Xbox needs a direct connection to the TV to do HDR and Atmos?
 
I've hit similar with the B7, I have a Denon x3600h and haven't tried running it through that yet instead of going direct to the TV and sending audio back with eARC, my understanding is the Xbox needs a direct connection to the TV to do HDR and Atmos?

B7 does not support eARC.

The B7 is ARC only which is PCM 2.0, Dolby 5.1, Dolby+ 5.1 Atmos, DTS 5.1

You don't need a direct connection for HDR & Atmos the Denon X3600 supports both of these via HDMI pass-through.

So connect the console directly to the X3600 HDMI and set the audio output to bitstream Dolby which will output Dolby MAT (PCM 7.1 + Atmos). You will have to cycle the TV picture preset to game mode manually as the B7 does not support automatic low latency mode (only 9 & X series OLED).
 
I have no idea where I got that idea from :facepalm:

Ran it through the amp today and it looks 100 times better 😁

I've not noticed a huge need to change the picture mode tbh from a latency perspective, whether it's the stuff I play or my age I don't know
 

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