HDMI Arc Signal Not Supported from LG CX OLED on new WiiM Amp

[jbnati]

I just hooked up my HDMI ARC (using cable from WiiM amp) in the correct HDMI 2 port on my LG CX OLED (this automatically synced perfectly with a cheap Yamaha sound bar) and now when I switch to the WiiM Amp HDMI input I get this error saying it doesn't support the audio signal AC3. I don't know that I can change the output audio format, and if this doesn't work, It kind of defeats the whole point of buying this WiiM Amp as an all-in-one solution.

Any thoughts on this? Is it a format that is coming? Am I doing something wrong? Is this an LG firmware issue potentially?

 

[xsdmx]

Watching carefully, I have an LG C9 and a WiiM Amp on pre-order, so this would be a deal-breaker. FWIW the Arylic B50 and NAD D 3045 play nicely with my LG C9 with everything forced to PCM Stereo.

 

[jbnati]

The goal is to be able to simply use my Apple TV Remote to control the WiiM amp volume. It’s baffling that this worked seamlessly on a mid Yamaha sound bar. I am updates my LG CX software currently and will see if this helps. Stay tuned.

 

[xsdmx]

I know my config doesn't map 1:1 with your setup (Nvidia Shield vs. Apple TV), but here's my known good configuration:

• LG C9 TV
• Nvidia Shield Pro (2019)
• Arylic B50 or NAD D 3045

B50 or NAD D 3045 -> HDMI Port 2 (eARC) on LG C9 TV using 2m 18 Gbps HDMI cable
Nvidia Shield Pro (2019) -> HDMI Port 4 on LG C9 TV using 6ft 18 Gbps HDMI cable

LG C9 TV Settings:

• HDMI Port 4 as PCM Input
• Audio set to ARC in PCM mode
• Don't use Bitstream or Passthrough anywhere because the B50, NAD D 3045, and the WiiM Amp can't do any HDMI decoding beyond PCM Stereo. Only the Bluesound Powernode Edge has eARC with DD decoding support IIRC (unfortunately it's underpowered and doesn't support Chromecast!)
• CEC Simplink enabled

Nvidia Shield Settings:

• Dolby Processing enabled (DD+ software codec stack for gapless playback with different streaming sources but no change if I disable and instead use software codecs
• Audio output forced from Auto to HDMI
• CEC power and volume control enabled

The Arylic B50 (crackling/clipping) and NAD D 3045 (random shutoffs and overheating) both have some issues of their own, but with this setup I can control everything from my single BT Nvidia Shield remote: volume, power-off/standby, all work flawlessly.

Update: I received my WiiM Amp and it works totally fine under the same exact condition excepting CEC standby which is fixed in the next firmware update that I haven't received yet.

 

[xsdmx]

AC3 is DD and the WiiM Amp only supports PCM Stereo, so somewhere in your chain, it's trying to send AC3/DD through to the WiiM Amp which cannot be decoded. Ensure everything is forced to PCM Stereo.

 

[jbnati]

I know my config doesn't map 1:1 with your setup (Nvidia Shield vs. Apple TV), but here's my known good configuration:

• LG C9 TV
• Nvidia Shield Pro (2019)
• Arylic B50 or NAD D 3045

B50 or NAD D 3045 -> HDMI Port 2 (eARC) on LG C9 TV using 2m18 Gbps HDMI cable
Nvidia Shield Pro (2019) -> HDMI Port 4 on LG C9 TV using 6ft 18 Gbps HDMI cable

LG C9 TV Settings:

• HDMI Port 4 as PCM Input
• Audio set to ARC in PCM mode
• Don't use Bitstream or Passthrough anywhere because the B50, NAD D 3045, and the WiiM Amp can't do any HDMI decoding beyond PCM Stereo. Only the Bluesound Powernode Edge has eARC with DD decoding support IIRC (unfortunately it's underpowered and doesn't support Chromecast!)
• CEC Simplink enabled

Nvidia Shield Settings:

• Dolby Processing enabled (DD+ software codec stack for gapless playback with different streaming sources but no change if I disable and instead use software codecs
• Audio output forced from Auto to HDMI
• CEC power and volume control enabled

LG CX software update and reboot seems to have fixed this (THANK GOD, as my entire Xmas plan was hinging on this Polk Signature towers and all). I'm still trying to see if the WiiM is auto-recognizing the HDMI input and auto switching to it. Sorry for these posts on day one of the new device.

The power, function and finish seems AMAZING though.

 

[Mr Ee]

I'd be surprised if you can't change the tv output to pcm.

 

[jbnati]

You can see now on the HDMi input reads as LPCM instead of the AC3 in the previous screen shot.

 

[matd]

I am having the same issue. I just posted a thread in more detail. Please post if you find the solution.

 

[jbnati]

I am having the same issue. I just posted a thread in more detail. Please post if you find the solution.

I’m stupid and in a rush to set things up was still sending a surround 5.1 signal from Apple TV through to the WiiM. Just go into the audio settings on whatever you’re using and make sure it’s just stereo and not Dolby surround

 

[Woody]

I have a question about connecting the WiiM Amp along with a soundbar for LG TV.
Should I do HDMI Arc out of TV to soundbar, then HDMI out of soundbar to the WiiM if I want to occasionally use stereo speakers for TV sound?

Will both the soundbar and stereo speakers play? Seems like it might if the signal is passing through the soundbar on the way to the WiiM.
What do people use for a center channel when using the WiiM for TV audio? It would be cool if the soundbar could act like a center channel but I don't think that would be an option.

Thanks

 

[jbnati]

I don’t think this will work because you have to run the hdmi from TV into the ARC hdmi (out, even thought it’s technically input)on the soundbar. I don’t think the other hdmi will send anything not being arc.

 

[Woody]

I don’t think this will work because you have to run the hdmi from TV into the ARC hdmi (out, even thought it’s technically input)on the soundbar. I don’t think the other hdmi will send anything not being arc.

I didn't have much luck yet, but it may be me not making correct connections too. I don't think I know how the connections should go between TV and soundbar and then to amp. I do see LPDM on the WiiM app and it thinks it's playing but I hear no sound. Swapped HDMI's around between Arc and other inputs.
My Directv box only has one hdmi on it connected to an HDMI port on the TV. ARC out of tv to soundbar. That part works. I tried soundbar to amp and tv to amp but just thinks it's playing but no sound.
Life would be simple if a HDMI splitter could work between Directv box and WiiM amp. Are splitters, ok? I was able to use coax out from STB to Amp and that worked but had to put a converter in the mix and more wires in the mix.

 

[WiiM Support]

I didn't have much luck yet, but it may be me not making correct connections too. I don't think I know how the connections should go between TV and soundbar and then to amp. I do see LPDM on the WiiM app and it thinks it's playing but I hear no sound. Swapped HDMI's around between Arc and other inputs.
My Directv box only has one hdmi on it connected to an HDMI port on the TV. ARC out of tv to soundbar. That part works. I tried soundbar to amp and tv to amp but just thinks it's playing but no sound.
Life would be simple if a HDMI splitter could work between Directv box and WiiM amp. Are splitters, ok? I was able to use coax out from STB to Amp and that worked but had to put a converter in the mix and more wires in the mix.

Hi Woody,

Please use the HDMI Arc port on your TV to output audio to the WiiM Amp. If the WiiM Home App shows LPCM but there's no sound, please submit a ticket for prompt assistance. I appreciate your patience.

 

[jbnati]

I didn't have much luck yet, but it may be me not making correct connections too. I don't think I know how the connections should go between TV and soundbar and then to amp. I do see LPDM on the WiiM app and it thinks it's playing but I hear no sound. Swapped HDMI's around between Arc and other inputs.
My Directv box only has one hdmi on it connected to an HDMI port on the TV. ARC out of tv to soundbar. That part works. I tried soundbar to amp and tv to amp but just thinks it's playing but no sound.
Life would be simple if a HDMI splitter could work between Directv box and WiiM amp. Are splitters, ok? I was able to use coax out from STB to Amp and that worked but had to put a converter in the mix and more wires in the mix.

You just have so many things in the loop. The WiiM amp isn’t really made to work with an active sound bar. It’s best use is for passive speakers between the TV and those speakers.

 

[Woody]

Hi Woody,

Please use the HDMI Arc port on your TV to output audio to the WiiM Amp. If the WiiM Home App shows LPCM but there's no sound, please submit a ticket for prompt assistance. I appreciate your patience.

Hi,
I used the LG tv Arc port and see LPCM on the app but no sound at this point.

 

[egOscar]

You just have so many things in the loop.

I agree. Simplify, remove the soundbar out of the equation for a while, check the TV digital output, it needs to be stereo

 

[Woody]

I agree. Simplify, remove the soundbar out of the equation for a while, check the TV digital output, it needs to be stereo

I believe I did by connecting the ARC port to the Amp input.
The TV is connected to the satellite box through a regular HDMI port and then out to the Amp on the ARC port.
Should it be another way?

 

[WiiM Support]

Hi,
I used the LG tv Arc port and see LPCM on the app but no sound at this point.

Hi Woody,

To assist you swiftly, could you submit ticket through the WiiM Home App? Just go to 'Settings' > 'Feedback'. We'll start troubleshooting right away. Thank you!

 

[Yoku-San]

I believe I did by connecting the ARC port to the Amp input.
The TV is connected to the satellite box through a regular HDMI port and then out to the Amp on the ARC port.
Should it be another way?

You should connect the WiiM Amp to the HDMI Arc Port oft the TV. And the Satellite Box to a different HDMI input of the TV. And enable PCM output via HDMI Arc and HDMI CEC Features in the TV settings.