[ANSWERED] hdmi over wifi: multiple projectors

[eight]

I am looking to connect 4 projectors using 4 hdmi outputs on one computer streamed over wifi adapters. Are there wireless hdmi transmitters/receivers that will not interfere with each other in one venue?

I would appreciate your sharing a practical experience with such setups.

Thanks.

[Juriaan]

@eight

Why is it required to do it wirelessly over WiFi? Anything display related in my opinion should be done wired

[mark_m]

@eight

I don't have a practical experience of sending from computer to projector wirelessly, but I do have practical experience of bringing HDMI signals from camera to receivers wirelessly.
I managed to set up four independent channels using Teradek Bolt units over 5Ghz, each sending an independent signal to a switcher with no interference. Apparently more is possible with their newer units which operate also in the 6Ghz range.

Teradek is the industry standard for film-makers. Low lag, and reliable. That's what I'd use in your situation.  Curious to know what you're trying to achieve: do your projectors need to move around the venue? 

[eight]

@mark_m Thanks! After a bit of chatgpting, I am also leaning toward Teradek Bolt. My use case is the multimedia lab whereby students move the projectors a lot and we got tired of fragile cable management. Also I noticed lately that theatres, even big venues are slowly moving to wireless hdmi.

[mark_m]

@eight

Interesting. My experience here in the UK is that venues are increasingly running everything over ethernet, hard wired into the building. Video, audio and control are plugged into RJ45 or Ethercon patch panels, rather than old school analogue ones. I've not come across anywhere that does wireless HDMI. Frankly, I'd be wary of doing that in a professional setting. 

With the Teredek Bolt you're attaching a pretty expensive bit of kit to each end of the projection chain, and each end has to be powered too.

The alternative is to make the cable management less fragile... What about a solution where your computer outputs to an HDMI to ethernet adaptor, and you connect via etherCon and heavy duty ethernet cable? The cable is robust, and cheap, and ethercon protects the RJ45 connector well. And it's a fraction of the cost of Teredek's equipment. But maybe your multimedia lab is very well endowed with lots of money! Not something which happens here.

Extron make robust and affordable HDMI extenders where you only need to power one end.

If your projectors have HDbaseT inputs, then even better, you only need a device at the computer end. Some HDMI to HDbaseT devices will also transmit LAN information, so you can control the projector via LAN...

Just thinking out loud really... 

[Michel]

@eight here at our university we use the Hollyland Mars 4K for Kameras: https://www.hollyland.com/product/mars-4k
They are cheaper than Teradek but they have a delay, they say 60ms on the website but its rather 70ms.

Best Michel

[DillTheKraut]

@mark_m

Second this. I generally prefer properly wired connections, as wireless can never be as reliable. But there are scenarios.
We do that a lot at our theater in both directions, from wireless camera connections to free movable displays as a sink. Just now for a production we got a freely movable multi display platform, which gets its feed from two our Teradek bolt 4K lt 750. But it needs quite some experience and knowledge to navigate the caveats.
E.g. an issue to be aware of, can be the 5Ghz Wifi Networks in the same room. Especially if you go to have wireless (NDI) streams from a mobile device in the same frequency bands. As the Teradek doesn't recognize existing wifi networks, they just overpower them if on the same channel. This needs proper channel management, especially in Europe where most of the 5Ghz channels are DFS (radar saved) channels, leaving only two fixed channels for two wireless sets.
Therefore, if it doesn't need to be second hand for budged reasons, I very much recommend the 6Ghz versions.
For indoor usage, I can recommend the Mushroom Antennas as an upgrade. They are available for both Ghz variants and added connection stability for us big time. We don't have any experience with the internal antenna variant though.