If you don’t know the difference between HDMI 1.4 and 2.0 or 2.1, then read on because it is the difference between buying a TV for today and one for the future. We also discuss HDMI cable types and why they are so important.
We will stick to TVs, and soundbars/AV amps for now but HDMI (High-Definition Multimedia Interface) is the most common single cable audio/video interface between two devices.
HDMI devices include all TVs and most soundbars, Blu-ray/DVD players, PlayStation, Xbox, Set-top Box, PC/media centre, cameras and more. By TV we also mean a video projector, PC monitor or even a digital audio device.
First some definitions
- HDMI ARC (Audio Return Channel) simply means that the HDMI cable works both ways for audio – for example, the soundbar can receive audio from the TV and vice versa.
- HDMI eARC (enhanced ARC) is a new standard that means more features, faster speeds and higher quality video and audio. This is on newer and more expensive 2019+ TVs like Sony’s A9G OLED.
- HDMI CEC (Consumer Electronics Control) means you can use the TV or soundbar IR or BT remote control to turn on/off both devices, volume, and some basic play features. Its also known as Sony Bravia Link or Sync, Samsung Anynet+, LG SimpLink and many more.
- HDMI Audio is up to 8 channels (7.1) for HDMI 1.4, and 32 channels for HDMI 2.0/2.1. It has 16/20/24-bit, sample rates of 32/44.1/48/88.2/96/176.4/192 kHz or will passthrough (on some TVs) Dolby Atmos or other content to an Atmos soundbar for processing.
- HDCP (High Bandwidth Digital Content Protection) protects Digital Rights of content makers via encryption – it is to prevent content copying.
- HDR (High dynamic range) includes metadata in the video stream. HDR10, HDR10+ and Dolby Vision/IQ are supersets of HDR. HDR is static meaning that the TV only adjusts the picture once at the beginning. HDR10+ is dynamic and can adjust the picture on a scene-by-scene, and Dolby Vision/IQ can adjust frame-by-frame.
- HLG (Hybrid Log-Gamma) is how TV stations will transmit 4K free-to-air TV.
HDMI started in 2004. It quickly took over as a single cable solution and on all TVs.
All you need to know is that it has versions 1.0, 1.1, 1.2, 1.3a, 1.4, 1.4a, 1.4b, 2.0, 2.0a, 2.0b and now 2.1. HDMI devices and cables are backwards compatible to the extent that earlier versions simply do not support latter features.
We will focus on HDMI 1.4 to 2.1.
This supports 10Gbps and 4K (4096×[email protected], 3840×[email protected]/25/30Hz) as well FHD (1920×[email protected]) or less. It also supports Ethernet (HEC), ARC, Adobe RGB, and 3D TV (although that really did not work well until 1.4b).
If you are buying a lower-cost 4K TV, then 1.4/a/b (that’s or a or b) is all you need for today. It will support everything you can connect to it, but you won’t get Dolby Vision or Atmos passthrough.
There are two types of HDMI 1.4 cables (both varieties can have Ethernet options as well).
Most low-cost cables are Category 1. No matter how good your 4K Blu-ray may be, you can’t get more than 1080p and 720p on your TV. These can be up to 13m, but in practice anything over 3-5 metres is dodgy. Do not buy Category 1 if you have 4K devices!
There are also Category 2 ‘high speed’ cables that support 4K and 3D. These can be up to 5-metres but are typically 2-metres.
But the catch 22 is that there are generally no markings on the cables so assume that these are all Category 1 and that means not suitable for connection of 4K devices to a TV or soundbar.
HDMI 2.0 – [email protected] compatible
This ups the speed over HDMI to 18Gbps but needs Category 3 ‘Premium High Speed’ (optionally plus Ethernet). It supports Rec. 2020 colour gamut 24-bit colour, 32 audio channels, dual video streams, four audio streams, static HDR (HDR in 2.0a and HDR10 in 2.0b) and HLG (2.0b).
This is more than adequate for 4K TVs, Dolby Vision/Atmos and current devices.
HDMI 2.1 – 4/5/8/[email protected] compatible (includes Ethernet)
This takes the speed to 48Gbps, and cables are 48G or ‘Ultra High Speed’. As cables are backwards but not forwards compatible you should buy HDMI 2.0 or 2.1 compatible if you can afford to.