HDMI Cable Length: Is there a magic number?


AV Pro often gets questions on why their tech support recommends using 2 meter cables when dealers and customers have certain issues with signal over HDMI cables. Below is the answer.

The truth of the matter is that HDMI would never tell you, you could not use a short cable. However, in HDMI 1.4 the HDMI Reference Cable equalizer was added to make up for signal attenuation of higher bandwidth signals. This equalizer is meant to start amplifying signals at about 2 meters but can sometimes be activated below. With the HDMI 2.0 specification being up to 10 meters, cables that are shorter than 2M can become over amplified ("too hot") to be read correctly while cables longer than 10M may have too much attenuation ("too cold").

When the signal is too hot, you may see image flash in and abruptly cut out, audio may randomly clip, and other strange anomalies in the HDMI signal. As sources continue to update from HDMI 1.3/1.4a to 2.0/2.1 we have continued to see a slow rise in the number of times this happens.

Currently the Apple TVs, PlayStation, and Xbox all come with 2-meter cables.

From my experience working with other non AVPro products, Integration, and time spent working on the CTA CEB23. A 2-meter cable isn't always necessary. However, writing it into the SOP will help prevent unnecessary truck rolls for having to swap out a cable.


Jan 06 23 PAA News

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