Originally Posted by Hotobu
I just ordered an LG CX TV, so now I need to get an HDMI 2.1 cable, but I do have a few questions.
1. Currently I am using a non eARC receiver (probably 10 years old), I use my TV's audio out via HDMI. I'm pretty sure I don't have to worry about upgrading the receiver or this cable, but I want to ask to make sure.
2. Are all HDMI 2.1 cables pretty much the same as was the case with 2.0? Do I need to look for anything specific other than 4K 120Hz etc.?
3. I need something in the 25' range, but they're all extremely expensive (and rare). I'm seeing prices around $130 for 25ft. Is this the best that I can do right now?
First of all there really aren't any cables that have been fully certified for the HDMI 2.1 option sets so you need to read the product descriptions very carefully. So no, not all "HDMI 2.1" cables are even close to being the same. Second of all, you don't need to have a cable that is supposedly able to handle some or all of the HDMI 2.1 option sets to fully enjoy your new CX. Most all of the HDMI 2.1 option sets are not available on commercial devices yet nor are there any devices that can utilize the 48Gbps bandwidth required for the higher video standards, let alone source material. And lastly, there aren't any "HDMI 2.1" cables. If the cable follows the marketing guidelines required by HDMI.org, they can label their cables as Ultra High Definition HDMI cables, which implies the HDMI 2.1 option sets but they must list which option sets the cables have been tested for. Keep in mind that "Ultra High Definition HDMI cables" is not the same thing as "Ultra HDMI cables" or similar marketing. That's done to confuse the consumer.
Some cable mfrs have indeed tested the connectors following CTS to meet some or all of the HDMI 2.1 option sets so that's what you want to look for. Currently there are only a very few handful of cable mfrs who list that in their product descriptions.
If you are concerned with eARC and VRR for example, those two options are part of the HDMI 2.1 option set but are also possible with the current HDMI 2.0 chipsets if the mfr chooses to offer a firmware upgrade path. That being said, a device mfr could list that their product is HDMI 2.1, which it technically is if they offer those options, but it could be nothing more than an upgraded HDMI 2.0 chipset. You don't need 48Gbps for eARC or VRR.
25' is tough for any cable if you are wanting to push 4k HDR and ARC/eARC. Distance is still problematic for 4k HDR and beyond. The original cable spec for HDMI 2.1 passive
cables was 1m - 3m maximum (3' - 9'). That distance has been increased for passive cables but the wire gauge is thicker, so you will lose bend radius (flexibility) which may result in increased strain on the HDMI ports, which is no bueno. For longer distance runs and 4k HDR, a hybrid fiber cable is recommended (Ruipro4k for example). Those cables have been tested by an ATC following the guidelines and testing protocols designed and implemented by HDMI.org but being as the hybrid fiber cables are active, they can not be called certified by HDMI.org nor receive the QR label for authenticity like the passive, up to 25', Premium High Speed HDMI cables can.
At 25' you should also be running your cables in a 1.5" - 2.0" conduit for easy and safe installation. That way you can replace your cabling as need be without too much difficulty. Video standards will always outpace connection standards so you need a way to keep up, and a properly installed conduit is the way to do that. The ONLY way to future proof your cabling is to use conduit.
Regardless of what a cable mfr claims in their product descriptions or marketing materials, no one can guarantee that their cable will work 100% of the time for all setups and situations. What ever cable you get, lay it out on the floor first and thoroughly test it before installation to make sure that it meets your expectations and needs.
If you are using a 10-year old receiver, then yes, you will absolutely have to upgrade your receiver if you want to take full advantage of 4k HDR and what your new tv is capable of.
The cable is just a data pipe. It can not alter or modify the signal that it carries in any way. What determines what you can see and hear are the HDMI chipsets in the source and sink end devices, not the cable. It's also best that your devices all have the same version of HDMI chipsets to eliminate any compatibility issues. In other words, if you have a device that is HDMI 1.4 pushing data to a device that is HDMI 2.1, you will only be able to utilize the in-common protocols, which in that case would be HDMI 1.4. You will get a usable signal (backwards compatibility) but it will only be with the HDMI 1.4 option sets.