The HDMI Rabbit Hole

Close up photo of HDMI connector on the back of a DVD player

I recently bought a new 4K HDR TV. The old one had gotten a bit long in the tooth but it had always annoyed me with its awkward resolution of 1366×768 which sits in no man’s land between 720p and 1080p.

It was bought in the days when high-definition televisions were entering the market but the content wasn’t yet readily available, sound familiar to you 3D or 8K TV owners out there? At the time, in Europe at least, a certification programme was introduced to prevent manufacturers from claiming they were producing TVs that were ready for HD content when they weren’t – which in my opinion just made everything even more confusing.

With my new TV I wanted to move my A/V equipment to another location so I started to look for new cables when I fell down the HDMI rabbit hole.

I had a few prerequisites; the cables needed to be 5m long, flexible enough to follow corners closely and support both 4K and HDR (I know that there are different types of HDR but for the sake of my sanity I’m not going to cover that here).

HDMI has remained the de-facto standard on most A/V equipment with the physical interface remaining unchanged since its introduction. That is both a blessing and a curse. A blessing in that it maintains compatibility between new and old equipment. A curse in that in order to support ever increasing resolutions and features sets there is a casualty in all this – the cables.

Digging Deeper

To understand why it’s important to explain that in order for HDMI to support higher resolutions and added features without changing the physical interface the data rate needs to increase. The cable needs to support this by allowing signals of greater bandwidth to pass unhindered. If this doesn’t happen then things don’t work properly or stop working altogether.

As I’m writing this there are 13 versions of the HDMI specification!

HDMI Specification
Version 1.0 – December 2002
Version 1.1 – May 2004
Version 1.2 – August 2005
Version 1.2a – December 2005
Version 1.3 – June 2006
Version 1.3a – November 2006
Version 1.4 – June 2009
Version 1.4a – March 2010
Version 1.4b – October 2011
Version 2.0 – September 2013
Version 2.0a – April 2015
Version 2.0b – March 2016
Version 2.1 – November 2017

To make things even more complicated the specifications can contain optional features which aren’t always implemented by manufacturers.  

With all this is mind where do you even begin when trying to find the right HDMI cable?

A light at the end of the tunnel?

It helps to know that as the HDMI standard has evolved 7 different types of cable were defined:

Cable Types
HDMI 1.3 introduces:
High Speed
HDMI 1.4 adds:
Standard with Ethernet
High Speed with Ethernet
HDMI 2.0 adds:
Premium High Speed
Premium High Speed with Ethernet
HDMI 2.1 adds:
Ultra High Speed (includes Ethernet by default)

With the introduction of HDMI 2.0 a certification programme was created for Premium High Speed cables to confirm they meet the necessary requirements (cables that have been certified are sold with an official label). At this point you might start to dust off your hands and think to yourself – job done – however not all manufacturers appear to be bothering with this certification including some of the larger names in the field. D’Oh.

*As a slight aside there isn’t a certification programme for Ultra High Speed cables yet.

At this point if you want to find that right HDMI cable for your new setup you’re just going to have to get stuck in by doing some research, browsing the internet or reading online reviews. You’ll need to compare what the cable offers with what your equipment supports, no small task. Looking at the HDMI versions supported by your equipment is a good way to start.

Getting a head start

You can be pretty confident that cables from high-end A/V manufacturers (i.e. Chord and AudioQuest) will work without any problems but you pay a small fortune for the privilege which for most people including myself is not an option.

AmazonBasics cables are highly rated, incredibly well priced, but from my own experience are quite thick and inflexible. You’ll find that the longer the cable the thicker it will be to counter the effects of signal attenuation. For most people these cables are all you’ll need unfortunately they way I wanted to route my cables, to keep them out of sight, this wasn’t going to work.

There are manufacturers who sell fibre optic HDMI cables, which are incredibly thin and flexible and come in long lengths (we’re talking 25m+ here which is possible as optical fibres do not suffer from signal attenuation in the same way electrical wires do). Again these are quite expensive and not always bi-directional due to the complexity of converting to an optical signal so please aware of this especially if you need your cables to support Ethernet.

In the end I found a German manufacturer called KabelDirekt who sold reasonably priced cables that were quite thin and flexible and available in the lengths I needed. I’ve been using these for a couple of months now and have not had any problems with them. Success.

What does the future hold?

While HDMI has successfully move A/V from the analogue to digital age it is not without its own drawbacks. I did have to spend an unreasonably long time trying to find the right cable.

Long gone are the days when the back of a TV had an endless list of connections to support various formats (i.e. composite video, S/PDIF, component video etc.) all to be replaced with a handful of HDMI connections. The problem you now face is that HDMI cable you have in the bottom drawer might not support the newest features supported by you’re A/V equipment and unless its clearly marked you may never know this leaving you with the only option of buying a new cable.

So many features have been added to HDMI over the years that I can’t think of any way to clear up the current situation for the typical consumer. In fact manufacturers are aware that this is a problem. It would not surprise me if the next generation of interconnects move from being dumb carriers of information to smart connections with handshaking protocols to manage compatibility issues for you similar to what Apple and Intel have done with the Thunderbolt interface.