Yamaha (TSR-700) and LG (75QNED80ARA) HDMI connection issue

[rnaeye]

This is driving me crazy, and I really want to understand the cause of it. My Yamaha and LG TV are connected by eARC port. I run apps from my TV, such as Apple TV and Prime Video. By chance, I have discovered that if my HDMI cable is "High Speed, HDMI Cable 2.0 (4K) 18Gbps" everything works fine. However, if I connect TV to AVR by a higher spec cable for example "Certified 2.1 8K HDMI Cable 48Gbps 4K120Hz", I have following issues: Yamaha display flickers and sound keeps cutting, and even nothing plays I can hear low popping sound time to time. I know this is not the cable issue as I have tried two different 8K HDMI cables which are different brands.

I was wondering what is causing this? By using "High Speed, HDMI Cable 2.0 (4K) 18Gbps" am I compromising anything. I either stream or watch Bluray or 4K movies played by a Panasonic Blu Ray player which output 4K60Hz maximum. I have no game console.

 

[lovinthehd]

Why run the higher spec cable then? What specific cables and lengths are you using?

 

[rnaeye]

Why run the higher spec cable then? What specific cables and lengths are you using?

Short answer is that the cables are 2m (= 6.6 feet) long.

Why am I trying to run higher spec cable? Long story: My 4K Roku box started buffering a lot when I streamed (download speed was low although my Wifi speed is excellent). I was trouble shooting including HDMI cables, and I happened to have higher spec cables in hand as my existing cables did not have any labels on them. Later I figured out the specs from my shopping history. It was easier for me to stream from Smart TV (no buffering) instead of troubleshooting Roku box (another mystery for me). This is where I am at now.

 

[lovinthehd]

Short answer is that the cables are 2m (= 6.6 feet) long.

Why am I trying to run higher spec cable? Long story: My 4K Roku box started buffering a lot when I streamed (download speed was low although my Wifi speed is excellent). I was trouble shooting including HDMI cables, and I happened to have higher spec cables in hand as my existing cables did not have any labels on them. Later I figured out the specs from my shopping history. It was easier for me to stream from Smart TV (no buffering) instead of troubleshooting Roku box (another mystery for me). This is where I am at now.

At that length I'd think even properly rated cables wouldn't have any advantage. I'd think more about your service provider than the hardware spec especially as cables didn't help. Claimed specs are only so reliable otoh. Maybe more information could help but seems you've covered the necessary so far....

 

[everettT]

Short answer is that the cables are 2m (= 6.6 feet) long.

Why am I trying to run higher spec cable? Long story: My 4K Roku box started buffering a lot when I streamed (download speed was low although my Wifi speed is excellent). I was trouble shooting including HDMI cables, and I happened to have higher spec cables in hand as my existing cables did not have any labels on them. Later I figured out the specs from my shopping history. It was easier for me to stream from Smart TV (no buffering) instead of troubleshooting Roku box (another mystery for me). This is where I am at now.

Your issue is with your network. Can you not hardwire the Roku? Also speed alone doesn't tell the whole story with the quality of connection. Can you screenshot a speed test from the Roku or phone?