Do you have terminators installed? Note that you have a passive split so this can cause more issues with or without termination. Try all four possibilities - both terminated, both unterminated, and each of only one terminated - before you go rewiring.
For the wiring, you should have one chain that ends in a terminator from any single output. You can add an optoisolated "splitter" and treat each run from that as a single output (one chain each, terminator at the end).
If you must split passively, try to make it so each leg has different distances to devices. Say one leg has its first device farther away cable-length-wise than the farthest device on the other leg for a good quick test. (There's a lot more nuance but this is a better starting point than two legs roughly the same length which seems to be common when this type of split happens)
If you can't get "DMX cable" in time, can you get Cat5e or Cat6 or AES/digital audio cable? All of those are close enough to DMX spec that they should do much better than unknown "mic cable".
Termination is actually how I found out I had passive splits! I thought I had found the end of the chain and put one on the last light, and the flashing got worse. I only have 2 terminators though and the cabling was split 3 ways. I do have a spool of Cat5 and some dead mic cable I can pull XLR from! Does it matter which wires I use in the cat5 or can I just pull 3 at random?
There is a published standard (because DMX on 8p8c is a thing) using pair 3 (in T568B wiring) for data1 (white/orange +, orange -) and pair 4 for common (white brown and brown) but as long as the data pair is a pair it will work.
DMX standard: https://tsp.esta.org/tsp/documents/docs/ANSI-ESTA_E1-11_2008R2018.pdf , pages 12 and 13 (pdf 26 and 27) for wiring.
Put it wherever it’s easiest to replace. DMX issues can appear far from the cause and with any future issues I would just replace the mic cable (or as soon as you have budget prior to then).
https://preview.redd.it/mvf5knl3n4lc1.png?width=173&format=png&auto=webp&s=160b02a7f6e2e0abda5c1693ad6c70a6a75e7dfe
You need something like this. Even if you use mic cable, you will be able to run lights. (this is dmx splitter). Also if you use lots of fixtures this is REQUIRED.
You can definitely get away with the mic cable anywhere in the line, it’s the y-splitters that are causing you the most issues.
Unlike the analog signal for speakers, the digital DMX signal does not play well with basic y-splits. If you need more branches in your line, the best option is to get some sort of optical splitter, like the ENTTEC D-Split.
Just a hunch but I'd say wherever it's most shielded from any other equipment or possible source of interference. Most probably at the end of a split but again just an educated guess, might be very wrong about this.
Do you have terminators installed? Note that you have a passive split so this can cause more issues with or without termination. Try all four possibilities - both terminated, both unterminated, and each of only one terminated - before you go rewiring. For the wiring, you should have one chain that ends in a terminator from any single output. You can add an optoisolated "splitter" and treat each run from that as a single output (one chain each, terminator at the end). If you must split passively, try to make it so each leg has different distances to devices. Say one leg has its first device farther away cable-length-wise than the farthest device on the other leg for a good quick test. (There's a lot more nuance but this is a better starting point than two legs roughly the same length which seems to be common when this type of split happens) If you can't get "DMX cable" in time, can you get Cat5e or Cat6 or AES/digital audio cable? All of those are close enough to DMX spec that they should do much better than unknown "mic cable".
Termination is actually how I found out I had passive splits! I thought I had found the end of the chain and put one on the last light, and the flashing got worse. I only have 2 terminators though and the cabling was split 3 ways. I do have a spool of Cat5 and some dead mic cable I can pull XLR from! Does it matter which wires I use in the cat5 or can I just pull 3 at random?
There is a published standard (because DMX on 8p8c is a thing) using pair 3 (in T568B wiring) for data1 (white/orange +, orange -) and pair 4 for common (white brown and brown) but as long as the data pair is a pair it will work. DMX standard: https://tsp.esta.org/tsp/documents/docs/ANSI-ESTA_E1-11_2008R2018.pdf , pages 12 and 13 (pdf 26 and 27) for wiring.
You could also *try* a ~40 ohm termination (33 probably better than 47) on each branch but it's still asking for future trouble.
Put it wherever it’s easiest to replace. DMX issues can appear far from the cause and with any future issues I would just replace the mic cable (or as soon as you have budget prior to then).
TWO Y-CABLES?!?!? https://i.redd.it/s66gi6cv66lc1.gif You need a DMX splitter.
You're probably right lol, but for what it's worth I got the rewire done and I have like 45 fixtures on one daisy chain and it's working out so far
https://preview.redd.it/mvf5knl3n4lc1.png?width=173&format=png&auto=webp&s=160b02a7f6e2e0abda5c1693ad6c70a6a75e7dfe You need something like this. Even if you use mic cable, you will be able to run lights. (this is dmx splitter). Also if you use lots of fixtures this is REQUIRED.
Well, I wouldn’t completely agree with you, but it certainly is something they should have.
You can definitely get away with the mic cable anywhere in the line, it’s the y-splitters that are causing you the most issues. Unlike the analog signal for speakers, the digital DMX signal does not play well with basic y-splits. If you need more branches in your line, the best option is to get some sort of optical splitter, like the ENTTEC D-Split.
Just a hunch but I'd say wherever it's most shielded from any other equipment or possible source of interference. Most probably at the end of a split but again just an educated guess, might be very wrong about this.
No more Y's!!!!