First off use the search function you'll find a wealth of information already here on
DMX and DMX Cable.
A favorite saying around here:
"I run DMX over audio cables all the time and it works."
"Well you can run DMX signal over a barbed wire fence, but it's not advisable."
DMX cable is data quality cable. It can carry a signal around 1000 feet without any problems. 3 pin
XLR microphone cable is audio cable. It has a totally different
impedance and the DMX signal degrades very quickly in mic cables. The DMX signal only uses three of the 5 pins in a standard DMX line (the last two were reserved for features that have never been added). The lower end manufacturers decided to keep things cheaper for their clients by using 3 pin XLR connections instead of a proper 5 pin. This works fine If you are a DJ and you only have a few devices located less than 20 feet away from you. But as soon as you try spreading them all around a room or running them from the opposite end of the room, the cheap short cut fails. By the way if you decide to upgrade to DMX cable, whatever you do don't mix DMX cable and
microphone cable. You will make things even worse than they are now.
DMX cables are expensive. A 50' DMX cable will run you a minimum of about $45-$50. Another interesting solution is Cat 5 cable. It's also data cable and available in giant spools very cheaply. Just solder on some XLR plugs and you are ready to
roll. Unfortunately it's not very durable so it probably won't work for you. Do a search on DMX and
CAT5 for more on this topic.
Do you terminate you lines? Lack of termination can lead to all kinds of weird issues. Don't know what that means search for
DMX termination or DMX terminator.
Finally you cut down on the length of your dmx run by splitting into multiple lines with a DMX splitter (look out they are expensive). Check out Doug "Dr DMX" Fleenor's
website for a lot of good information on what DMX is as well as to buy a splitter.
EDIT: Dang it Alex, Did you have to
sneak in and answer faster than I could? Well I'm leaving my post up anyway because I used the cool Barbed wire quote!