Print

Please login or register.
1 Hour 1 Day 1 Week 1 Month Forever
Login with username, password and session length

[Vic Cowles]

Silly me!  

I've been using mic cables to run lights all these years.  I now understand that there is a difference.
between mic cables and DMX cables. Can anyone explain this more more on this?  I see DMX 5 pin cable available but
not 3 pin.

Thanks!

Vic

[Dave Nuss]

Hi Vic,

I have been told the main difference in the physical characteristics of each cable lies in the capacitance. Also more often than not mic cable will work and work for a long time but issues can creep in over time or so I have been told (also the length of the cable plays a big part). Belden 9729 or equivalent is the standard for installed applications and there are more flexible cables available made for general use. Also Cat 5 has been vetted for use as DMX cable.

There are 3, 4, and 5 pin DMX cables out there all depending on what the manufacturer chose to use. I believe most newer items use 5 pin but things like Apollo Color Scrollers use 4 pin. Also most items only use 3 of the 5 wires too. The others are officially reserved for future use in the standard.

Dave

[Mac Kerr]

using mic cable is not recommended. you can get the real info here. The characteristic impedance of the cable is the important spec.

Mac

[Duane Massey]

Original DMX spec was a 5-pin XLR, with 4 & 5 reserved for future use. Since most of the major players in the US were using 3-pin connectors for their own protocol (LWR, Martin, etc) they more or less made a 3-pin the de-facto standard. It took a while, but almost all the old protocols died out, leaving the 3-pin still standing. You still see both 3- and 5-pin connectors in use. Either works exactly the same, pin-for-pin.
Again, original spec called for the Belden or equivalent braided shield cable. Most users opt for regular mic cables (off-the-shelf) or roll their own. We rarely use anything fancy, and I can recall only 1 instance where we had a problem; it was also an installation that had major issued with almost anything to do with cables, and there were several defective fixtures involved as well. Since none of the cables provided with the fixtures by the manufacturers are braided shiled or anything other than cheap 22g spiral wrap PVC cable, I'm content to use what works. YMMV, of course.
I am surprised at how few people install a terminator on the end of the chain. Of course, I'm also surprised at how often the system works quite well wihtout it. Go figure.
If you want to be as correct as possible, use the Belden cable.

[Jordan P.C. O'Neil]

Proper DMX cable is especially important on long runs, and/or where it is subject to to interference, ie any event production scenario.

If you are going to be making cables with 5-pin connectors, I recommend using 5-core cable, as it can be very useful if you want to run 2 DMX universes down one cable, or make long send/return runs.

Also look at Proplex cable:
http://www.tmb.com/Pdf/ProplexP-web.pdf
Its very durable, and strong enough to tow-start a car with!

[Martin Ø]

I think that 110-120 ohm is the right for DMX-cables. It's a bit lower on the mic-cables (70-90?). Thats the difference.

Based on what I remember atm.    So don't rely on it too much before you get it confirmed.

[Jonathan_Yacko]

can you use regular cat5 cable?

[Duane Massey]

Not reccomended.

[Ted Christensen]

Im glad i found this out, i have been using a channel in my snake for a while now, So now i would have to buy a 150foot DMX cable so i can work with my controller FOH?

[Duane Massey]

Ted, if it's been working, be happy and leave it alone.