Katarzyna Petru
The choice of the right cables is not just a matter in the world of audiophiles. Film enthusiasts often debate the superiority of one HDMI cable over another, as price, build quality, length, or brand do affect the colours, sharpness, and accurate representation of the image. But is that really the case?
We can immediately say that any functioning HDMI cable will display the same colours, sharpness, and fluidity within its specifications regardless of price. However, it is important to remember that not all cables operate under the HDMI 2.1 specification, so purchasing the cheapest cable may not be sufficient for everything to work properly.
To clarify this somewhat complicated topic, we conducted a test of the Purelink PS3010 cable priced at 99 zł, with its competitor being the Wireworld Starlight Platinum cable priced at 4999 zł. Will an accessory that is nearly 50 times more expensive have an impact on image quality? In our scientific test, we will demonstrate that these two cables offer the same image quality, despite the enormous price difference.
However, if you are looking for reliable cables at a good price and do not want to scroll all the way to the end of the text, we have included links to the cables we recommend here:
The cable we used in this test, 3 metres long - PS3010 - ps3010 - Home Cinema eXperts Store (hcx.com.pl)
Long fibre optic cables - FXI380 - FXI380 - Home Cinema eXperts Store (hcx.com.pl)
Additionally, with the discount code "ChooseTV", you can receive an extra 15% off.
Types of HDMI cables
At the outset, we mentioned that each cable will display the same image, but within the scope of its specifications. Currently, manufacturers and sellers unfortunately make it difficult for consumers to differentiate the capabilities of a given cable by using phrases like 4K, 8K, HDR, etc. It should not be taken into account when manufacturers label the standard of the connector on the cable, e.g. HDMI 1.4. If our cable has such a designation, and the television is equipped with newer connectors, it does not mean that it will not function correctly. For a cable, what matters is how much data must flow through it, which is determined by technical parameters such as resolution, refresh rate, or colour encoding format. Below you can see how specifications have changed over time.
The correct designation of the cable is the class assigned to the standard, not the version of the connector. On the official website hdmi.org, we can find official explanations of these standards.
However, it is possible that we have encountered a situation where the manufacturer or the shop clearly described the cable class and the standard it is intended for, yet it still did not manage to achieve a stable image. Writing such markings does not guarantee that the cable will indeed meet them. Of course, we can complain about such a product, but this process can be burdensome. Cables longer than 3 metres are even more susceptible to such situations.
Then the aforementioned HDMI organisation came to the rescue, which introduced the official certification programme HDMI Premium Certified. Thanks to it, cables with the hologram below guarantee correct operation regardless of price and manufacturer, as they had to pass rigorous tests before entering the market. We can scan the QR code to confirm the authenticity of the certificate. Currently, there are two types of holograms on the market. The first indicates that the cable guarantees correct operation in the 2.0 standard, meaning a resolution of 4K and a refresh rate of 60Hz. Its properties are sufficient to support devices such as DVD players, Blu-Ray players, set-top boxes, or network players, e.g. Apple TV. The second hologram with the inscription Ultra High Speed ensures full compatibility with the 2.1 standard, meaning a resolution of up to 8K and a refresh rate of 144Hz. Such a cable will perform well with the latest generations of consoles or computers that possess such high specifications.
However, this does not mean that a cable without an HDMI certification will not work correctly. The Wireworld Starlight Platinum itself does not have such a designation, nor does the tested PureLink PS3010. The latter is used by us in the studio and has been subjected to many tests in every possible regard. That’s the theory, so let’s move on to the practical test of these two cables.
Laboratory tests of image quality
Let’s start with the fact that HDMI is a digital connection, so the electrical impulses flowing through the cable are interpreted as 0s and 1s. According to theory, if we interfere with them up to a certain point, nothing will happen, because the signal will still be read correctly by the receiving device.
What will happen when the device can no longer read zeros and ones? To check this, we deliberately cut the cable. As you can see, it consists of many layers that protect against interference. More expensive cables may have more shielding layers, which provide better insulation. They may also have thicker conductors made from higher quality materials.
See what phenomenon appears when using the cable we damaged.
Sparkling, grain, seed - these are the terms we most often hear when the aforementioned problem arises. In this case, the device is no longer able to accurately read 0 and 1. However, this does not affect the colours, brightness or sharpness.
There is also a second possibility, where the device uses HDCP protection, e.g. a Blu-Ray player or Apple TV. When we switched our generator to this mode, the image simply disappeared because it could not be decrypted.
As can be seen, even intentional damage to the cable does not result in a loss of image quality in the classic sense of the term.
This situation could occur with analogue cables such as Component, Composite, Scart, where voltage levels directly affected image brightness, rather than whether the image would be recognised as 0 or 1.
Cheap vs expensive cable
Surely you have already noticed that an HDMI cable will either work or it won't, and its price has no bearing on this. Nevertheless, to be certain about this statement, we conducted an experiment. The AccuPel signal analyser will help us with this, which can read what flows through the HDMI cable at the level of specific pixel values of the image.
We displayed a dynamic image on the television, and in the centre, we placed a sharpness pattern. High sharpness signifies a great contrast between adjacent pixels, so we used a pattern in which there is a jump from black to white. If the cable had the ability to influence sharpness, then the edge would become blurred or either the black or white would deteriorate.
First, we used a cable worth nearly 5000 zł. What was the effect?
The image looked good, and the cursors on our analysing device show that on this pixel, I have pure, almost bright white. And moving one to the left, we have deep black. This means we have a perfectly sharp edge here.
And what about the cable for 99 zł? To our (non)surprise, the results are exactly the same. As you can see, the edge is equally sharp, the white is bright, and the black is deep.
Delay on long and short cable
We often hear the question of whether the length of a cable has an impact on signal delay, which is crucial when gaming on a console or computer. In this matter, there will be some numbers, but we will try to explain it simply and clearly.
Electricity, or more precisely, the electric field, travels through the cable almost at the speed of light, which is 299,792,458 metres per second. The exact difference can only be measured in laboratory conditions, but even then, it is not visible to our eyes. The perceivable delay could be 50 ms, or 0.05 seconds. To cover an additional 1 metre of cable, 3.34 nanoseconds, or 0.000000003 seconds, are needed. Even a 100-kilometre cable would not show a noticeable difference!
What about a fibre optic cable with an active plug? Using a short cable costing 5000 PLN, the delay is 12 ms. After switching to a cheaper, 10-metre fibre optic cable, the result is exactly the same.
The price of the cable also does not matter in the case of the available functions on consoles, as the cable itself is supposed to provide the appropriate signal bandwidth, while the support for functions is a matter of the devices on both sides. An exception might be old cables without an Ethernet channel, through which the audio return channel ARC may not function.
We have scientifically proven that in the case of an HDMI cable, there are 3 scenarios that may occur.
The cable works correctly and processes the image
The cable processes the image, but artifacts appear on it
The cable does not display the image at all
It does not affect the colour, brightness, sharpness, or overall image quality.
Problem of long HDMI cables - fibre optic cables
Cables longer than 3 metres can pose problems when trying to maintain a stable connection. Shorter ones are often less prone to transmission errors, and even older models can handle the HDMI 2.1 standard without the required certifications.
If we are looking for a long cable, we will likely need to search for a fibre optic cable.
These have a built-in modulator in the plug that converts electrical impulses into light, which can travel several dozen metres without any issues. We included a link to proven models of such cables at the very beginning of the article. Of course, one can look for cheaper solutions, and all cables with the official HDMI Ultra Certified Cable certification should work fine, even if the price is suspiciously low. At least that is what the members of the HDMI Forum assured us during our conversations at CES in Las Vegas. For our part, we recommend the aforementioned cables because they have well-seated plugs, which minimises the risk of breakage in the socket, which is quite high with long cables. After that, replacing a cable embedded in a wall or other rigid enclosure is difficult or practically impossible.
However, if you, dear reader, are still in the process of finishing your flat, we recommend using conduits in the wall that will allow for cable replacement in the future, when the standard develops further and the current specification becomes insufficient.
In situations where this cannot be applied, let us try to lay the highest-grade S/FTP twisted pair cable that will allow for HDMI transmission using special modulators.
Summary
In summary of our test, cables working with the same signal cannot deliver different colours, sharpness or brightness, regardless of the price or quality of the given wire.
The capabilities of the cable are clearly specified by the assigned classes. The following classes, mentioned earlier, are currently in effect.
Cables with this designation guarantee functionality, as do those we recommend. Of course, older cables without additional certifications can also work, but we may experience image dropouts or audio crackling, or the sound may not return from the television to the external speakers, which means the need to replace the cable.
