ARC between Denon x3400H and LG TV, my 8m UHD HDMI cable does not work (which one does?)

Whiskey Jack

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I have a Denon x3400H and an LG Oled55C8PLA TV which are about 8m apart. My original 10m HDMI cable (bought in July 2014) works great, including ARC, for anything up to 1080p. However, it can't manage 2160p.

So I bought a MOSHOU optical fiber HDMI 2.1 cable via Aliexpress that works great for all ultra HD content, including HDR. Figured I'd get an optical and high spec one to future-proof as much as possible (cable needs to go in a wall eventually). The cable quality is great and it should even support eARC. And while the x3400h should do so as well, the TV does not (yet at least).

The problem is that I can't get ARC to work with the new cable. While I sometimes need to switch inputs or turn the receiver off and on for it to work with the original cable, ARC works most of the time without problems. With the new cable the receiver does detect something as it switches input to TV Audio, but no sound is then forthcoming :( The supplier of the new cable can't help or test my setup and suspects it is a "compatibility issue".

As there's only so much you can try with changing settings, I don't have much hope in getting ARC to work. Still, any suggestions are most welcome (is there a way to get debug logs or something?). In absence of that, are there 4K cables with ARC confirmed to work for my setup?

For reference both the TV and the receiver have the latest firmware:
LG 55C8PLA: 04.10.15, WebOS TV-version: 4.1.0-5608)
Denon X3400H: 7400-9134-6431-1084

Many thanks!
 
I am confused here. AFAIK there are no 2.1 cables, as there are no commercially available 8k sources to reference with. This has been widely discussed throughout the industry. So how anyone is claiming a 48 GB cable is beyond me. I would suggest that you talk to @Joe Fernand about a RuiPro hybrid cable that seem to be very highly rated and afaik support ARC. They are not 8k cables (as they don’t exist yet) but fully functioning 4K optical hybrids
 
Thanks, I'm not fussed about the 8K or 48 GB at all. Just picked the highest spec fiber cable with good reviews. I'll have a look at RuiPro.
 
Thanks, I'm not fussed about the 8K or 48 GB at all. Just picked the highest spec fiber cable with good reviews. I'll have a look at RuiPro.

Given the completely false claims & false advertising of this MOSHOU cable, & the fact you can't get any support at all, is it even worth keeping it?

Unfortunately, it seems you've been sucked in by one of the common misconceptions of HDMI cables. The cables themselves don't have versions per se, they're just "standard" or "high speed" for example. The connections on your hardware itself is what has the compliance with the different HDMI versions, such as HDMI 1.3a, 1.4, 2.0a/b, etc., etc..

Wouldn't it be worth testing an Amazon Basic's HDMI cable which can definitely support the features you need? ( https://www.amazon.co.uk/dp/B01JH710HI/ref=twister_B019OW05QS?_encoding=UTF8&psc=1 ). They're rated for 4K@60Hz, ARC, HDR, 3D & ethernet. They're highly rated for their price & complaints are rare.

If it works as intended, send the MOSHOU cable back ;). If it doesn't, just return the Amazon cable under their 30 day returns anyway, & then look at other alternatives or options after that :). Personally, I wouldn't have gone anywhere near MOSHOU, (whoever the hell they are lol???)

Hope you get sorted :).
 
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Should have know about those Amazon cables, usually I just get my Kindle books from them ;-)

Seems like a plan though, for that price I will probably just order one of those and test if it works. Thanks.
 
Should have know about those Amazon cables, usually I just get my Kindle books from them ;-)

Seems like a plan though, for that price I will probably just order one of those and test if it works. Thanks.

Hope it solves your probllems :). Let us know how it works out ;).
 
I support the RuiPro suggestion for a fully functional UHD connectivity solution above 5m. It's the only thing I've found that works reliably. (Thanks to Joe).
 
I bought the 7.6m Amazon cable to try it out. According to the reviews there is a chance it won't work well, but mine works fine: 4K with HDR, ARC, all good.

However, it is a very thick and stiff cable and it may pose some challenges getting that through the duct in my wall. We'll see, thanks for the suggestions!
 
I bought the 7.6m Amazon cable to try it out. According to the reviews there is a chance it won't work well, but mine works fine: 4K with HDR, ARC, all good.

However, it is a very thick and stiff cable and it may pose some challenges getting that through the duct in my wall. We'll see, thanks for the suggestions!

Glad you've at least got priority No.1 sorted lol. Excellent visual & audio, 4K@60, HDR, ARC, etc., etc. :).

At least you've determined that it can all be good with a longer HDMI run, with the right cable. Fingers crossed you can successfully route it now :). I have several high speed HDMI cables of varying lengths, from different manufacturers. Anything of 3 meters & above does tend to be a thicker gauge & not particularly pliable. If routing becomes an issue, you may need to look into the solution suggested by @mushii & @Mark.Yudkin :).

Otherwise, find out what gauge your longer Amazon Basic's cable is & then have another trawl around on Amazon to see if it can be matched for specs at a similar price, but perhaps a couple of mil's or one AWG thinner for easier routing. At least they're so much easier to return if you run into the same problem again. Returns to AliExpress can be awkward!! Are they allowing you to return the Moshou cable?

Enjoy :).
 
I am confused here. AFAIK there are no 2.1 cables, as there are no commercially available 8k sources to reference with. This has been widely discussed throughout the industry. So how anyone is claiming a 48 GB cable is beyond me.

HDMI version numbers dont apply to cables. They never have.

The new cable spec is from the category 3 test suite and is labelled “ Ultra “ and is tested to 48 gigabits bandwidth, so “ 48G” is also a term being officially used.

All cables are tested using simulated worst case signal conditions with a tektronix rig or similar.
Signal conditions are generated by the rig as per signal conditions laid out in the specification document.

For example , category 2 or “ high speed” cables have always been tested to 4K since 2009 or thereabouts, long before any real content was available.
( assumptions at the time were 4K was going to be 4096 x 2160 at 60fps)

Category 3 or “ ultra” tests to 10/11k and beyond based on possible future signals as laid out in the spec.

The issue with “ Ultra “ and cable sellers is that some sellers have been claiming “ Ultra” certification since last summer.
This is impossible since....
1. Hdmi.org and its Authorised Test Centres are the only way to get that certification.
2. The CTS or compliance test document has only just become available and ATCs will take time to upgrade and start testing. Without the CTS you cannot do the tests and cannot get the certification.
There is no retro active certification.

So anyone up to now claiming ultra spec for their cables has been lying.
 
Thanks @andy1249, nice to know how things really work!

And yes, I was offered to return the cable, although with a max of $10 for shipping costs (which doesn't cover it). In the end I decided to keep the cable and save me the hassle, I know it will come in handy when I want to play pc games on the big screen ;-)

And with a bit of creativity (rounding the straight angle corners of the plug, add a bit of Vaseline) I managed to get the Amazon cable through the wall, barely :)

Learned a lot here, thanks all! On to the next question! (ARC is still not working 100% on my Denon as it should).
 
Thanks @andy1249, nice to know how things really work!

And yes, I was offered to return the cable, although with a max of $10 for shipping costs (which doesn't cover it). In the end I decided to keep the cable and save me the hassle, I know it will come in handy when I want to play pc games on the big screen ;-)

And with a bit of creativity (rounding the straight angle corners of the plug, add a bit of Vaseline) I managed to get the Amazon cable through the wall, barely :)

Learned a lot here, thanks all! On to the next question! (ARC is still not working 100% on my Denon as it should).

Well done routing your cable :). Another milestone passed!!

You said in an earlier post that your ARC was all sorted with the new AB cable lol ;)!!

What's going on exactly, more details :)? Is it working but not producing 5.1 & you're only getting stereo PCM for example? Not working at all? Dropouts? Which apps? Netflix, Prime Video, etc., etc.?
 
Probably would need to create another thread for this (planned to do so after some more testing) but in a nutshell; often, usually when I turn everything on, ARC from the TV (e.g. with Netflix) is not working. When I then turn on my media player connected to the Blu-ray input, ARC will start working after a few seconds, without even switching inputs back and forth on the receiver. It's so strange I cannot come up with any explanation.
 
Probably would need to create another thread for this (planned to do so after some more testing) but in a nutshell; often, usually when I turn everything on, ARC from the TV (e.g. with Netflix) is not working. When I then turn on my media player connected to the Blu-ray input, ARC will start working after a few seconds, without even switching inputs back and forth on the receiver. It's so strange I cannot come up with any explanation.

Its a pain, but not really strange, ARC is a subset of CEC, and manufacturers are allowed to do anything they want with CEC commands.
Most have their own unique set and brand name for it, bravialink, simplink, anynet, vieralink and so on....
This makes CEC and ARC flaky as hell.

Most likely there is a conflicting “toggle” command that turning on your media player just happens to toggle the “ working” way.

At least you have a known method that works.
ARC is the most asked about feature of HDMI on here.
Its hard to help because of the way its abused/used by manufacturers, often the only advice is to forget ARC and use optical instead.
 
Its a pain, but not really strange, ARC is a subset of CEC, and manufacturers are allowed to do anything they want with CEC commands.
Most have their own unique set and brand name for it …

Laviasync, Simpleton, Anyoldnet, and Veraduckworth. :lesson:
 
I get problems with the cec on my setup, pioneer vsx-934 and Samsung 7020, when I turn on the tv the av does not turn on, so I turn it on, volume etc all fine.
When I turn the tv off cec kicks in fine and turns off the av.
strange
 
One of the most important things about the new shift to eARC is that it is now independant from CEC.
This means it should just work, and not fail because of some quirk in the way the manufacturer has implemented CEC.
There should be a lot less problems with it.
 

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