I wonder about some

Facebook throws up some interesting feeds. The one I am following on a couple of techie pages is certain fun, but worrying. It is all about using microphone cable for DMX. A lot of people seem quite happy to use mic cable. They do not realise that if something goes wrong with the DMX system it is most likely that one audio or 2 audio cables. A lot of the admitted to using audio cables instead of DMX cable, and it giving problems until they switched out the cable. We are a professional industry, should we not act like it and use the correct tools to make sure that the event goes without a hitch and we are seemed to be professionals. It seems if they can get away with this cost cutting idea they will. I hope though if it fails they will man up to the error and at least compensate the client whose event they have stuffed up. I know I would not be happy as a client if something went wrong that the service provider had some control over, by using the correct materials.

These guys seem get the gigs constantly and they are bringing the industry down. So read some of the Facebook comments below and let me know what you do – I dare.

Below are the two questions asked on the two different Facebook pages, and some samples of the comments. Quite a lot were trying to do the right thing and adhere to the standard. Plenty were using mics cables and just getting away with it. You will also notice that some people referring to XLR as if that is a audio cable and not a connector.

Also there arose questions about terminating DMX, which also lead to a variety of unusual answers.

Below the quotes I have provided 2 links for those that want more info about DMX.

The First Question: 

Can someone help settle a debate… can you use sound XLR cables as DMX cables for your lighting in a theatre that has over 20 intelligent fixtures? Would anyone trust it?

The Second Question:

Ok guys. I’ve been told that XLR and DMX cables are interchangeable with zero negative results. I’ve read otherwise. I know for a fact they can be used interchangeably in a pinch. Thought it’s certainly not my choice to do so. Has anyone actually experienced a problem themselves by swapping them? Not looking for theory, but real world experience. (EDIT) I mistakenly used the terms XLR vs DMX referring to the cable itself when clearly XLR is a connector. The question is 3 wire mic cable vs 3 wire DMX cable.

 

Some of the comments:

  • Alot of entry level fixtures (fixtures at what I consider to be the community theater level) are getting better at including 5 pin ports. If you’re buying new cable: go for five pin. If you have existing, quality pro audio cable stockpiled use that.
  • The worst reason for doing something wrong is “we have always done it that way”.
  • Yess no problem if the are good quality…
  • I’ve done it for multiple tours in big theaters with no problem.
  • Can you? Yes. Should you? No.
  • in new zealand 3 pin xlr and dmx are the same
  • I patch DMX via my mic/tie lines in a 18K hockey arena all the time and never had an issue with runs upwards of 700+’.
    Can you have issues? Sure but in most situations, no. YMMV.
  • Ive been using mic cables for dmx a while now and hemave zero negatives
  • The fact that doing it wrong has not bit you in the ass yet does not make you correct.

Best Reply (Similar to my own) :

Way to many people using the “it’s never failed me yet so it must be correct”.

Even when corrected.

Weak argument and only serves your ego, rather than look at your practices and improve where lacking.

if I walk into your stage and see mic cable used as dmx, I WILL think less of you and the company you represent.

When I ask for proper cable, and am rebuffed with that weak sauce excuse, I will make a note to avoid you and your company.

It will also raise my awareness and I’m gonna start looking for other hack issues. I.E. removed ground pins on stingers, burnt gel, proper cross bracing on decks, correct gauge on cables for load and run.

Do it right.
Be a professional.
It’s not hard.

LINKS

https://en.wikipedia.org/wiki/DMX512

The second link talks about RS – 485 which is what DMX is based on.

https://www.maximintegrated.com/en/app-notes/index.mvp/id/763

Termination or not. A diagram.

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