Newbie lighting question

[idchafee]

Hi all

 

This is my first experience with lighting. The school bought 12 LED lights that are mounted on a rack above the stage. They bought a 100ft 3-pin DMX cable (I think, from what I read in the manual) to go from the lights to the control board. Problem with that is, 100ft leaves the control board in a place I'd really rather it not be. My question is, can I use a longer cable? The salesman who sold them the lights told them no, that they needed a wireless unit. I wonder if that's correct or if he was just looking for some more commission.. I googled and found this:

 

Horizon H3DMX Lighting Cable 3-Pin M-F 200 FT

 

Is that a cable that will work? The last thing I want to do is create issues because I want to move the control board.

 

Thank you in advance

[southhamster]

DMX is based on RS485 and should go to 300m T least. However when we had ours installed the suppliers strongly advised us to use a powered splitter as they said that long daisy chains caused problems. It wasn't hugely expensive and gives us more versatility and expansion potential too. They said they have used wireless but prefer cabling.

[ItsOggy]

Hi, if you just need another couple of Metres, do you have a 3-Pin Mic cable around... try it.

[3s-gtech]

I would definitely stick with wired. Try extending it, though bear in mind that a microphone cable may not meet the standard (though they're the same electrically IIRC). Worst case, you may need to re-route.

[Zipsterr]

Hi Guy's

 

Yes stick to wired we have! We had to extend our cables a few meters. Its like with any cabling, you can be to long which will cause issues but I would say you will be safe adding a few mtrs onn Give it a try and good luck!

[Chockster]

You shouldn't have any trouble with a longer cable. Might be worth getting a terminator for the end of the run (the last light in the chain) if there's not one there already.

[SamanthaD]

100ft is nothing. How do you think the guys running festivals get their DMX signal from the Front of House control board to the stage?

 

Your sales rep is doing his job - trying to sell you stuff. You can quite happily go to 150ft / 50m or longer no worries. If you don't want to buy a new longer cable extending your old one is fine too.

 

If your lights are all in one line then I would just run that cable to your desk - however you might want to consider if you want to relocate them at any time a powered DMX buffer box located on stage would be handy. This will give you optically isolated splits to each area and keep the signal at a decent level.

 

As for cable, mic cable and DMX are virtually identical except for one major difference - the resistance. You need 110 ohm cable for DMX (it's a digital signal so it matters). You can use mic cable, and it will work, but when you start to push the limits it's things like this that get missed. You can, however, use DMX for audio and it's fine!

 

Any questions feel free to ask.