The truth about the 120 Hertz HDMI cables

Since the HDMI cables are used in almost all home theatre setups, many merchants are trying various techniques in order to sell their products. You can find cable advertised as super high speed, ultra-speed, gold, platinum, and priced at more than a hundred pounds. The truth is that in 99% of the cases, a good quality HDMI cable, which you would not pay more than twenty pounds, is likely to work just as well as the super expensive ones. The labels that some merchants use are misleading and at times, in violation of the HDMI Licensing.

Let us take a closer look at the so-called 120 Hertz HDMI cables. Every video consists of a number of frames, which are displayed quickly and they give the illusion of “moving pictures” – for instance, the video content in an NTSC-based country is shown at 30 frames per second and the video content in the PAL-based countries at 25 frames per second. However, film is recorded at 24 frames per second and in order to be displayed properly, it needs to be converted to 30 frames. This is done by using a 3:2 pulldown process. After the LCD and plasma TVs appeared, they started using a technology, which introduced the refresh rate. The refresh rate denotes the number of times a television image is reconstructed per second and the idea is that higher refresh rate delivers better quality picture. When the frames per second meet the refresh rate, things get even more confusing – for instance, a TV with 120 Hz refresh rate repeats each frame 5 times every 24th of a second in order to display 24 frames per second.

Since the 120 Hz signal has twice the frame rate of a 60 Hz signal, the consumers are misled to believe that they would need a special, 120 Hz HDMI, which is the only one that could handle the increased bandwidth. The truth is that the cable simply transfers the signal from the source (Blu-ray Disk Player, HD DVD player, etc.) to the TV and whether the TV is 120 Hz or 60 Hz, this bandwidth stays the same. Most sources have signal frame rate of 30 Hz, 60 Hz, or 24 Hz and the internal refresh rate of the TV makes no difference. With that said, what HDMI cable do you need to buy in order for your setup to work? In most cases, all you need is a good quality, 1.3 or 1.4 HDMI cable, and you definitely do not have to spend hundreds of pounds on it in order to get excellent quality picture and sound!

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