HDMI Distance Limitations

One common area of confusion for structured cabling professionals entering the world of AV installation is that of HDMI distance limitations.

Coming from an industry where distance limits are very clearly defined it's not surprising that many expect to find similar standards-based certainty when it comes to HDMI distribution. Instead, system designers are confronted by ambiguous and often conflicting advice which is easily misunderstood and creates a potential for possible failure, signal loss or intermittent performance. Aside from physical distance, other factors which affect signal strength such as separation from sources of interference and minimum bend radius are less clearly defined and so further add to the risk of poor performance.

Here we set out to give, in simple terms, some general guidance and explain some of the options available for ensuring signal integrity over distance in typical enterprise environments.

Standard vs. Premium HDMI Cables

- Standard HDMI cables should be expected to carry 1080p signal upto 15mtrs and low bandwidth 4k signals upto 10mtrs in good conditions.

- Premium Certified HDMI cables are specifically designed to support higher bandwidth signals and are capable of carrying full colour depth (4:4:4) 4k signals upto 7mtrs.

Once distances beyond these are required we need to look at alternative constructions and, since these solutions incorporate active send/receive components, it’s at this point we begin to see connectivity with designated Source (or Input) and Display (or Output) ends.

Active Optical Cables (AOC), as the name suggests, include active components to send and receive signal and are made using optical cable rather than copper. HDMI can also deliver low voltage current and this is used to power the active components, therefore no external power supply is needed. AOC leads can be expected to support complex high performance signals upto around 20mtrs. 

HDMI Extender Kits utilise CAT5e/6 network cabling to convert and transmit HDMI signal over 4-pair data cabling. RJ45 terminated horizonal cabling is connected to a transmitter unit at one end and a receiver at the other, HDMI leads then connect these units to the AV source and display respectively.

The distances achievable with these kinds of extenders are typically in the region of 50-100mtrs with variance between one manufacturer to another, the cabling used and the resolution of signal to be carried (1080p or 4k). Being active electronic devices these extender kits require external power sources.