This is a follow-up to my previous article regarding designing and installing native 4K UHD A/V equipment. I encountered more technical issues that may surprise you.
If you read my previous article, you were introduced to the challenges involved with pushing a native 4K UHD HDR10 signal 40′ to a projector. After my A/V setup was complete, we began to notice the audio would consistently get ahead of the video, causing a sync problem that was thoroughly annoying. I found that if I paused and re-started the stream, it would re-sync and then would gradually worsen again. After weeks of troubleshooting the previous issues, this was perplexing and overwhelming. Then it occurred to me, with all the focus on A/V equipment, I had totally lost track of the network data component of streaming this content.
Here I was trying push potentially 18 gbps of data over an A/V cable, when my home network only supported 1 gbps! You might ask, how could these numbers possibly work? That answer (after some research) became: cached data streams and buffered streaming devices. My ISP wired our neighborhood for fiber awhile back, providing plenty of data bandwidth from the source, but I had ignored my home network from the ONT device at the service entrance forward. After research, I realized that my two year old router was hopelessly inadequate for streaming 4K. The latest routers have a 2.5 gbps WAN port to connect your modem/ONT, instead of the older standard 1 gbps. In addition, the newer home router tech (WiFi 6) devices do a better job of supporting multiple independent data streams. The new wireless WiFi standard itself is not the advantage, it is the increased processing throughput and caching capability of the hardware needed to support it. Our new router is not the top-of-the-line today and it is rated at 12 gbps of total data throughput across all data streams. Who would have thought your home router would need to be defined in this way? When your router can manage multiple large data streams more effectively, you have dealt with a big part of your battle streaming 4K programming. As my old router did, yours may be capable of Quality of Service (QoS) prioritization and yes, the feature was developed to address this challenge… but it alone will not be enough.
The final piece to this puzzle was… once again, the cable tech. We converted all cabling on my network to CAT 6 a couple years ago. I had no idea the tech had reached CAT 8. CAT 6 was rated at 10 gbps up to 100m, now CAT 8 is rated at 40 gbps up to 24m. In retrospect, if there was a manufacturer that offered a HDMI 2.1 Balun solution supporting copper CAT 8, I would have chosen it over the fiber-optic cable option. Instead, we just accepted the situation and upgraded once again, to CAT 8 cabling.
My video/audio sync issue is resolved now and I have learned a little more about the challenges of 4K UHD HDR10 tech. For a little more perspective, our home theater generates a true 4K image on a 12′ screen via projector. This is not your typical 75″ 4K TV located 6′ from your streaming device. While the number of pixels may be the same, somehow the amount of raw data required to support this true 4K projector at this image size is different.
Before I started this 1080P to 4K 2160P home theater upgrade, I had thought this would be easy. Who would have guessed there would be so many challenges! This tech has been promoted, sold and installed for several years now. I have come to believe the challenges were as much related to the 2160P pixel format, as the HDR10 color gamut and 24 bit HD audio. The data stream required is astronomical compared to the more common 1 gbps thinking today. It would seem, this is the window for professional services… just, how can you market services to a potential customer that has no idea they need it?