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[Keith Broughton]

I guess my point is that if works at 400m, then there is little to be scared about with 40m of cable.

OK....so if it works, what is the question?

[Lyle Williams]

OK....so if it works, what is the question?

Just sharing my findings so one day google can help someone out...

[Scott Holtzman]

Just sharing my findings so one day google can help someone out...

It doesn't help.  Just because it worked for you it gives a false sense of security.  We don't know what type of MIC cable you were using nor the inductive nature of your environment.

These threads are annoying and destructive because the OP is always looking for someone to justify doing something wrong or marginal.   The answer is you are giving up safety margin.  You want to take a chance at your lights going out on a critical show and the loss of business and reputation.

If you are doing middle school dances and this isn't an issue then I guess it's useful information.  The assumption here is everyone is a working professional and in my mind professionals don't use the wrong cable to save a few bucks.

BTW I speak from experience, I have made these mistakes, choose the easier softer path.  I ended up tossing out or giving away the garbage and only use the good stuff I should have bought in the beginning. 

[Nate Armstrong]

I make all my cables including Microphone cables  with 110 ohm dmx cable and Neutrik connectors.
Then I can use any of my XLR cable for mic or dmx.

[David Buckley]

It will work great, till it doesn't.

This.

If the show doesn't really matter, and the risk of failure is acceptable, then go ahead, save a buck or two, and use mic cables.

If you are charging money, or claim to be "professional", well, then, that's different.

[Lyle Williams]

It doesn't help.  Just because it worked for you it gives a false sense of security.  We don't know what type of MIC cable you were using nor the inductive nature of your environment.

These threads are annoying and destructive because the OP is always looking for someone to justify doing something wrong or marginal.   The answer is you are giving up safety margin.  You want to take a chance at your lights going out on a critical show and the loss of business and reputation.

If you are doing middle school dances and this isn't an issue then I guess it's useful information.  The assumption here is everyone is a working professional and in my mind professionals don't use the wrong cable to save a few bucks.

BTW I speak from experience, I have made these mistakes, choose the easier softer path.  I ended up tossing out or giving away the garbage and only use the good stuff I should have bought in the beginning. 

I did start the post by saying that proper DMX cables are the proper solution.

Note that 3-pin DMX only exists to allow people to use mic cables.  3-pin DMX isn't a "pro" solution, but it is a very popular one.

DMX is RS485 at 250kbps.  Carrying this over the twisted pair we're willing to trust our precious audio to isn't electrically very challenging.

If fears about reflections keep you up at night, just use a lower value terminating resistor.  :-)

[Scott Holtzman]

I did start the post by saying that proper DMX cables are the proper solution.

Note that 3-pin DMX only exists to allow people to use mic cables.  3-pin DMX isn't a "pro" solution, but it is a very popular one.

DMX is RS485 at 250kbps.  Carrying this over the twisted pair we're willing to trust our precious audio to isn't electrically very challenging.

If fears about reflections keep you up at night, just use a lower value terminating resistor.  :-)

I would hate to be called out for having the wrong cables.  I was speaking more on principal that validation from strangers in a forum under the auspices of soliciting an opinion is weak.  Personally I am so lazy and no by will pay extra for lighting I use wireless.  if it screws up the fixtures go in sound activated mode.  My light show is a bonus.

Those kind of decisions and risk reward analysis require more understanding of the situation than just technical.

Sent from my SM-T800 using Tapatalk

[Jordan Wolf]

Note that 3-pin DMX only exists to allow people to use mic cables.  3-pin DMX isn't a "pro" solution, but it is a very popular one.

I was under the impression that certain manufacturers had used 3-pin XLR for a more "proprietary" connection before 5-pin was accepted industry-wide.

I don't think you would find any [reputable] manufacturer that recommends or suggests using standard microphone cables for control interconnect.

[Tom Burgess]

...Note that 3-pin DMX only exists to allow people to use mic cables...

Now there's an interesting little tidbit that I've never seen put forth.  Is there an actual source for this?

[Chris Jensen]

I did start the post by saying that proper DMX cables are the proper solution.

Note that 3-pin DMX only exists to allow people to use mic cables.  3-pin DMX isn't a "pro" solution, but it is a very popular one.

DMX is RS485 at 250kbps.  Carrying this over the twisted pair we're willing to trust our precious audio to isn't electrically very challenging.

If fears about reflections keep you up at night, just use a lower value terminating resistor.  :-)

I always thought that the USITT DMX-512A standard called for 5 wires.  Even though 2 of those connections are reserved they are part of the standard. 

After reading the PLASA ANSI document it seems that any non 5-pin XLR type connectors are only allowed in very limited cases.   It does not specially call out 3-pin as being disallowed, but 3-pin is obviously not 5-pin.

See section 7 - http://tsp.plasa.org/tsp/documents/docs/E1-11_2008R2013.pdf

I have always wondered if MPX has historically affected DMX and its perception in anyway.  I wonder if any of the manufacturers that started using 3-pin way back when decided not to seek using the DMX standard.  The ANSI document did clearly state how to note the use of DMX in the manual and on the gear.  Do any of the 3-pin instruments actually list it as the official DMX standard, or are they using the protocol without actually calling it official DMX-512A.  See section 7 for this also.

If anyone has any other info please add on and correct me!

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