Comparing AV (e.g. HDMI) signal distances for in-room support

In a low-tech production environment you can still operate in-room captions. As long as you have an internet connection, a modern browser and way to get an audio feed into CaptionHub - and a way to get a browser with the transcription onto the screen, then you are set.

Sometimes however, distances between your operating laptop and the captions screen might vary and the impact on your cable choice for sending the browser screen signal back to your screen may warrant more than your standard issue HDMI cabling. Our recommendation would always to have the processing laptop as close to the captions screen as possible in a low-tech production environment, but if this isn’t possible, there are other options available e.g. for outdoor events where the laptop is operated in a building 20 metres away.

Timbra's browser-based caption window needs to be displayed on a separate machine or monitor from your production source. Understanding HDMI transmission distances will help you plan your in-room setup reliably.

How far will HDMI transmit your caption feed?

The distance HDMI can travel depends on the resolution and refresh rate being sent. Higher resolutions and frame rates require more data, reducing maximum distance.

HDMI @ 1080p – 15 metres

For 1080p caption display, standard HDMI cable will transmit reliably up to 15 metres. Beyond this, you may experience signal degradation or intermittent dropout.

HDMI @ 4K UHD – 7 metres

If you're running higher resolution display, transmission distance reduces to around 7 metres. Use Premium HDMI certified cable for this bandwidth.

For longer distances

If your caption display machine sits more than 15 metres from source, consider:

Always test your setup end-to-end before live event deployment.