HDMI and USB cabling

[altecsole]

Hi,

 

We have quite a few classrooms where the teacher PC is an island - some with floor boxes for connection to the board. Currently, these use projectors with SMART boards, but we'd like to move over to Interactive screens. Looking at the cable distance, all of these will be over 5m. What solutions can people recommend? Do I look to re-cable with HDMI and Active USB, or are there easier solutions?

 

Many thanks.

[hallamke]

We've had real hit and miss with cable lengths and interactive screens (ViewSonic Viewboards in our case). Running HDMI 2.1 cables direct (some up-to 10 metres) seems to yield good results. In the classrooms with installed faceplates we had issues with everything over 5 metres. We either have to drop the refresh rate to 30Hz to get a picture, or it doesn't work at all. This would seem to be a power issue as testing with desktop devices gives us no issues. Active HDMI faceplates are the ideal option as a solution but I've not found anything cost effective to try as of yet.

 

USB we have no issues with connections up-to 5 metres. Anything over that it seems to depend on the connecting device. Our staff HP Pro Books don't seem to like it, but some DFE Dell's and my XPS 15 work fine. This must be down to power delivery on the device side so active USB would certainly be the way to go here.

 

Ultimately testing with the devices that will be the primary users of the screens is key to this (in our experience only directly run HDMI cables have been universally successful). Our woes came when the layout of 16 classrooms was modified post install during an electrical re-wire.

 

Hope this helps

[synaesthesia]

I see a lot of hdmi over CAT6 installations and whilst they often work, they are another point of failure, require power sources and just a pain in the backside. Fiber HDMI however is cheaper (15m cables for around 40 quid) and far more reliable. Just make sure that the end on the desk isn't plugged in and out all the time, so you may also need to look at desk hubs to keep them permanently connected. Makes the whole setup easier though, especially if you can do them over USB-C so just a single connection to your laptops. USB is generally easier and "active" USB cables are cheap & reliable.

[PotNoodleTech]

Running up to 9 metre USB and HDMI here for smart boards but I use certified cables e.g. hdmi certified. Anythting more than that you have to do over cat5/6 ethernet.

 

Skimp on cabling at your peril if doing long distance.

[Rob_D]

For video we've had pretty good results from Kramer HDMI over Ethernet adapters. Data's be more of a mixed bag. Our current solution of 5m USB-c cables seems to be working okay, but we've not tried anything longer.

[synaesthesia]

Also note that each connection point adds a few metres in interference to your run - so a 5m cable with a wall socket (cable to back of wall socket, to front of wall socket) can be worth 10m of interference, plus a 2m flylead to the laptop is basically a 12m run. Hence so often why we have to make compromises. I don't let anyone install copper HDMI cabling as a result.

[Julian]

Similar experience, HDMI over copper does not like long lengths but sometimes can be made to work (by reducing the data rate, turning down the resolution, or reduce the refresh rate), always use good quality HDMI cables. USB similarly, we have had to use a powered USB hub as a USB repeater, to get working USB over the required length.

[TronXP]

All of our viewsonic boards are plugged in using Fibre optic HDMI cables, depending on the containment size, we are using Lindy cables or These from Kramer. For USB, we use the StarTech extender cables. I don't use faceplates, just a brush plate on the wall, cables through this, and straight into the computer/board. No major issues, and usually it's the device rather than the cable that is the issue.

[CHiLL]

We found that a lot of limitations were being caused by inferior HDMI cables and especially HDMI adapters in trunking. We now run HDMI 2.0b cables (4K60Hz) between the TV and the dock, as the installer installed a Vision TC3 HDMI module, which was limited to 4K30Hz and causing a lot of signal issues between the laptop and TV. The 4K60Hz version of this is eye wateringly expensive, which is why we decided to do direct runs.

[stevewill6]

We have had a lot of success with 10m active HDMI leads 4k30Hz (https://cpc.farnell.com/av-star/hhswa-10/4k-hdmi-lead-slim-aluminium-10m/dp/AV27759)

 

TV to wall box then 2m HDMI cable then to a HDMI Splitter

[FragglePete]

In a lot of installations where the HDMI cable was going beyond 5m we use HDMI Optical Cables - you pay a bit more for them but they resolved all the issues we were having with screens flickering, not sync'ing when the wind was in the wrong direction or just not display an image. USB we just use active USB Extender cables.

 

Pete

[altecsole]

In a lot of installations where the HDMI cable was going beyond 5m we use HDMI Optical Cables - you pay a bit more for them but they resolved all the issues we were having with screens flickering, not sync'ing when the wind was in the wrong direction or just not display an image. USB we just use active USB Extender cables.

 

Pete

 

Thanks for this. Pricing seems to vary wildly - do you have any recommendations for cables that work well, and aren't too expensive?

[psydii]

do you have any recommendations for cables that work well, and aren't too expensive?

 

Mutually exclusive options I'm afraid. Stuff that works well with your current device fleet might not work ok after a driver or firmware update, or the laptop/desktop you buy tomorrow.

 

The only cabling I have *never* had *any* problems with is the BlueStream stuff, either the 10m copper based stuff, or the 10m+ AOC 8K (overkill for today, but solves all problems in the universe).

 

Same with splitters, switches and cat5/6 converters, if you need it to work without a problem, Bluestream.

Edited March 10, 2025 by psydii

[SamanthaD]

One option not mentioned yet is HDBaseT. HDMI, USB, ethernet... all over one cable. The connections are quite forgiving (unlike bespoke HDMI over CatX solutions) so cheap ethernet cable should be fine if it's in spec.

 

If you look at the HDBaseT website there's a list of certified products, I quickly found this which might suit your needs? Have a ganders.

 

Otherwise for cables you usually can't go wrong with Lindy for USB (happily install 10m cables from them all the time) and Van Damme for active HDMI cable (their 15m acive cable never fails for us).

[synaesthesia]

One option not mentioned yet is HDBaseT. HDMI, USB, ethernet... all over one cable. The connections are quite forgiving (unlike bespoke HDMI over CatX solutions) so cheap ethernet cable should be fine if it's in spec.

 

If you look at the HDBaseT website there's a list of certified products, I quickly found this which might suit your needs? Have a ganders.

 

Otherwise for cables you usually can't go wrong with Lindy for USB (happily install 10m cables from them all the time) and Van Damme for active HDMI cable (their 15m acive cable never fails for us).

 

Just over a grand for those! I suspect a 50 quid fiber cable and an active USB extension/long cable will do just fine

I'm usually in favour for keeping things simple, no extra power requirements etc. Servicability may come into it, which is perhaps where hdmi over cat might have a very slight edge.

[3s-gtech]

We’re having a lot of problems with modular HDMI faceplates (basically a short HDMI extension tail). Ripping these out and pulling the cable out is improving matters considerably, on anything from 5m to 15m runs. Guessing they’re just junk but fewer joins helps.

[PotNoodleTech]

Yeh didnt go with faceplates here at all as the cabling is too important/finicky at 4k 60hz on the big boards - not like in the old days when literally any old VGA cable would do!

[FragglePete]

Thanks for this. Pricing seems to vary wildly - do you have any recommendations for cables that work well, and aren't too expensive?

 

We just use a local supplier who we have an account with here: https://adeptnetworks.co.uk/hdmi-active-male-male-lead-cable-fibre-4k

 

Yes, they are expensive but I see it as a trade off with time wasted trying to get these things to work and just paying for one of these cables and it works. Job done.

 

Pete