dmx cable and mic cable difference (ya ya ik but read!)

[DJ Higgumz]

I know that dmx cable is weaved data cable and shielded, and mic cable isn't and is signal cable. but I just bought a usb dmx dongle and want to try my lights, but only have 2 dmx cables, but tons of mic. now every lighting fixture says to not use mic cable due to interference damaging the fixture, but being in my own house without dozens of cell phones near it is it a danger? yet is it just hogwash they use to buy cable from them? do radio frequencies affect dmx transfer?

could I run dmx through an audiosnake? with the long run I would think the cable would be shielded. slightly noobish questions, but a detailed scientific explanation would help

[DJzrule]

To be honest, they work the same in the end. Its long runs and large scale setups that you start to get any interference in a real world environment.

[trauma11]

The best way it was explained to me is that XLR cables will work 999 out of 1000 times, so which show is going to be the .1%. Generally at large venues when we do sound and lights, we run the DMX console through the XLR Snake to the stage because it is way easier, but generally audio snakes are quality enough to be safe doing that. We've run through extremely old snakes at older venues and been fine, but it certainly wasnt my preference. The impeadence on DMX is generally 30-50 ohms higher than that of the wire in the XLR cable.

[DJzrule]

This. ^

On longer runs, I've had bounceback problems if we forgot to install a terminator. I'm actually investing in a Chauvet optoisolator specifically for the reason that I have to daisy chain too much when I need to run lights all over the venues.

[b.ill]

now every lighting fixture says to not use mic cable due to interference damaging the fixture

I've never heard that mic cable could actually damage to a fixture. Lighting experts is there any truth to this?

Personally I use DMX cable mostly but have substituted mic cable with no issues. Putting a DMX terminator on the end of runs with multiple fixtures has helped stabilize things though, so I always to that now. Those Hosa ones are only a few dollars each though Amazon.

[STLRiverCity]

I don't think using a mic cable will actually damage anything.

That said it can cause weird issues. I had 12 Chauvet Colorado Tour 1 fixtures over a total wire distance of 150ft. I accidentally used a 6' mic cable in the middle of the string and all the fixtures past that mic cable did not work properly. As soon as I replaced it with a DMX cable all was well. There was a terminator at the end of the string.

I have also had some issues with my DJ light rig that uses lower end DJ style lights when using mic cables.

That's just my experience. YMMV

[jmack953]

Depends on what side of the safety net you want to play. DMX has it's owns standards, or basically regulations, to be able to classify, what is 'acceptable' for DMX use. Within DMX512 protocol, it is stated and I'm gonna quote first, then simplify: " microphone and line level audio cables lack the requisite electrical characteristics and thus are not suitable for DMX512 cabling. The significantly lower impedance and higher capacitance of these cables distort the DMX512 digital waveforms, which in turn can cause irregular operation or intermittent errors that are difficult to identify and correct"
However, further reading on DMX512 standards also state the following: "Some equipment manufacturers have disregarded the formal topology rules, and designed their equipment to use nonstandard 3-pin XLR connectors rather than the proper 5-pin DMX connectors, so as to eliminate the need for the unused second pair and allow for the use of regular microphone audio cables. Similarly, end users can create adapter pigtails to convert from the correct 5-pin DMX to a 3-pin XLR microphone cable. For short cable runs of less than about 45 metres (148 ft) with only a few devices, it is sometimes possible to operate without termination. At short distances, cables with higher capacitance and different characteristic impedance such as microphone cable can be used. As the cable length and/or number of devices increases however, following the specification for termination and correct cable impedance become more important."

In a nutshell, NO, XLR Mic cable is not recommended BUT it can be used. Does it cause damage to lights?? Unverified unless you're the poor guy who has had it damage a light due to using XLR mic instead of DMX grade cable. But, if you ever need warranty repair from most manufacturers, be safe to say, they won't cover it if they know you were using a standard XLR cable on a 200 ft run with multiple pars and spots. Per say if it was a small DJ rig, 20-30 ft max, and maybe only running around 10 lights, you'd be a lot safer IMO. Really, take it with a grain of salt, and if you want to be ULTRA safe, get DMX grade cable and have all of your bases covered.
Best Regards, (not a "lighting expert" but use DMX frequently) - Jmack.

[jmack953]

PS... here's some good reading material if ya ever wanna jog the brain a bit and feed that cranium some interesting input

http://www.usitt.org/Resources/Stand...X512/DMX512FAQ