In theory no you don't need to
shield cables sending
DMX signal. Audio signal in my understanding is mostly an analog signal (think any decimal value between 0 and 1) and therefore very easily influenced by
electric and magnetic fields surrounding it.
DMX signal on the other
hand is a digital signal (0 or 1, no other options) and is more robust.
DMX doesn't have any error checking so if you had some really wonky
power you could see interesting things happen. My suggestion would be if you can easily get the wiring away from the other lines then it's worth doing to prevent a very unlikely bad data situation from happening, but given that the situation is very unlikely, if it's going to take a while, or any amount of money not considered petty cash, I'd just depend on the robust nature of digital signal.
As a side note,
XLR is a common style of
connector. Audio signal is most commonly sent through cables that have 3 pin
XLR connectors on them.
DMX signal is most commonly sent through cables that have 5 pin
XLR connectors on them. Saying "Shielding
XLR" doesn't actually make any sense when you're talking about shielding cable used for audio signal vs
DMX signal as they are both sent through cables that have
XLR connector.
Stagehand slag has decided that "
XLR cable" is a cable with 3 pin
XLR connectors that is suitable for transmission of audio signal and "
DMX cable" is a cable suitable for transmission of
DMX signal usually, but not always, having 5 pin
XLR connectors. I understood what you meant, I think, it's just a really big pet-peeve that I have developed because of some pretentious sound guys.