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DMX question

Discussion in 'Lighting and Electrics' started by Mplunket, Feb 1, 2004.

  1. Mplunket

    Mplunket Member

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    hi...i'm trying to put together a small light setup for my band for a concert. We were going to get 4 Chauvet Omega intelligent lights & a DMX-40 controller. I guess I'm just confused in general about how it all hooks up. Can you plug the daisy chain of lights strain into the controller? or do you have to plug the lights into a dimmer, and then that into a controller? if someone could just briefly describe how this works, that would be great, but i'm sure more questions will arise ;-) thanks
     
  2. Mplunket

    Mplunket Member

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    ok, here are some more pointed questions:

    - What exactly is the function of a dimmer? in relation to a controller?

    - In order to have a complete setup, with intel. lights & chases/scenes and everything, what all equipment do I need? (bare bones)

    well, i guess that's it for now
     
  3. cruiser

    cruiser Active Member

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    With moving lights, you don't need to plug them into a dimmer. It is much advised to run each fixture of a power point, if possible try to put each light on another circuit.

    And yes, the lights will connect together in a daisy chain fashion then straight into the controller box.
    Im not too sure about controller boxes but you might have to set the fixtures all too different address, eg. Fixture 1 is channel 1-24, Fixture 2 is channel 25-36 etc.

    Someone else might know more about the controller boxes??
     
  4. Mplunket

    Mplunket Member

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    coo, i just didn't want to throw down $180 for a dimmer, when it didn't seem to really add anything necessary hehe, well everything should work out pretty well. now i just need to learn the controller in & out ;-)
     
  5. cruiser

    cruiser Active Member

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    What kind of controller is it, make/model?
     
  6. Mplunket

    Mplunket Member

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    i haven't decided for sure yet...i wanted to get something thats fairly inexpensive, but could allow us to expand with more lights...that would also be easy to create chases/scenes and whatnot, i was looking at the DMX-40 and the Behringer Eurolight LC2412. Any recommendations?
     
  7. Nephilim

    Nephilim Active Member

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    We're using a Martin Freekie with three Chauvet Legend 150R units... overkill but it lets us grow (HA!).

    Make sure you buy 3-pin DMX cable and not microphone cable to join the Omegas together.
     
  8. Mplunket

    Mplunket Member

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    for now, that controller's a little out of our price range. our budget is like $800, and $600 we are throwing in to the lights.
     
  9. Nephilim

    Nephilim Active Member

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    Chauvet's own controller will suit you fine; it's designed for their fixtures and shouldn't cost too much.
     
  10. Mplunket

    Mplunket Member

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    coo, thanks for helping with the q's!
     
  11. DMXtools

    DMXtools Active Member

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    The Chauvet DMX-40 is identical (except for the logo silk-screened on the front) to the American DJ DMX Operator. 192 DMX channels, something like 240 memory scenes, 6 chases of 120 steps each, MIDI selection of scenes and chases from your sequencer (if you use synths in your band) - or for that matter, from a MIDI foot-controller if you dont use synths and sequencers.

    I've got one (the American DJ version) and am pretty happy with it. Does a nice job for the light setup I use for my local band shows. Not the best unit in the world by any stretch of the imagination, but the price is right - you can usually find them on eBay for about $150.

    You won't use dimmers for your intelligent fixtures, but you might want a few dimmers for PAR cans and relay packs for strobes and simple effects. While the DMX-40/DMX Operator is sold as a controller for moving lights, it does a good job with dimmers and relays as well.

    While it's best to use true DMX-rated cable, both Chauvet and American DJ say microphone cable will do. Experimentally, I looped my 100-foot snake through itself to put together 1600 feet of "mic" cable and ran my DMX signal through it. The cable type had very little effect on the signal quality, even at that distance.

    The most important thing is to buy or build a terminator and plug it into the DMX OUT connector on the last fixture in the daisy chain. A terminator is just a male XLR with a little 120 ohm resistor soldered between pins 2 & 3. If you're any good with a soldering iron, it's a lot cheaper to build your own.

    If you already have dimmer or relay packs from an older system that's not specifically DMX-512, whatever you do DON'T hook them into your DMX daisy-chain. The old mic. cable interfaces (micro-plex, LMX, Sunn-plex, Ultraplex, MUX-64 and MPX) sent power back to the controller on one pin of the XLR. DMX sends low voltage signals on the same pin. Hooking a DMX controller to an old MPX dimmer pack is like taking the speaker wires from your stereo amp and plugging them into the wall. It's not enough power to generate a LOT of smoke, but I guarantee it will fry at least one chip in the controller (and probably any other DMX devices you've got hooked up) as soon as you plug the old dimmer in.

    If you DO have old dimmer packs, check out my website - http://www.dmx-tools.com - I make a gadget to translate DMX-512 to the older protocols safely. They list at $239.95, but ControlBooth members get them at $100 off - just PM or email me.
     
  12. ship

    ship Senior Team Emeritus Premium Member

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    By the way, that's a extreme great price ya-all! Thanks DMX tools - too bad I bought my NSI translator years ago for about $150. I expect it's not anywhere as cheap, plus your equipment would not need a masters degree in electronics to figure out which internal electronics bridge to link in making it work.

    This while advertising is worthy and appropriate to the discussion. Next sales person that says we sell them also but does not explain much less help does not qualify in my book. Your's does. Too bad most don't have such an idea of private time and in kind favors. Great price and discount. Cool also that you completed the end product. To develop such a thing on your own, that says something all by itself. This is a master tech person ya- all, I'm barbarian electrics by the way but would understand both the good XLR cable but the lienance in it's other than use.

    Plus the only thing I would add is that most modern dimmers have a direct feed thru on the dimmers for DMX. Certainly you don't want to power up the moving lights thru a dimmer pack, but if it's DMX, and for cordage you can save yourself on a run in going light board to dimmer pack, than off to moving lights, it should work just fine. Terminate your last fixture unless it says it's not necessary or prooves not to be a problem.

    Another help type thing might be to rent controllers for another year until you have something with more growth to it by budet. That way in a few years when the program grows and it will, you won't be stuck with somehing that works now but not later. Also in confirming used gear is often a great value.
     
  13. DMXtools

    DMXtools Active Member

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    Thanks for the kind words, Brian.

    I'm not really recommending used gear on eBay, though, unless you like to tinker. There's a couple distributors selling new or factory-refurbished gear on eBay at rock-bottom prices - look in the musical instruments/DJ gear/lighting section.

    Mplunket - you might want to look at some of the package deals they have. If I was just starting out, there's a couple that would look pretty attractive to me. Heck, if I was ready to expand, I'd probably go with one of the moving-light packages and turn around and sell the controller.

    John
     
  14. Nephilim

    Nephilim Active Member

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    What brand of snake? It very well may have been extra-shielded and much higher grade than your average 'General Brand' XLR lead...
     
  15. DMXtools

    DMXtools Active Member

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    Pretty cheap ProCo - a Guitar Center special - higher capacitance, lower characteristic impedance than the DMX-512 spec calls for. The local-band sound-and-lights gig is pretty much a hobby - I can't really afford to spend a lot on really good gear for it. The saving grace is that I'm an electronics engineer and can repair any of it myself.

    Anyhow, RS-485 (the IEEE spec that DMX-512 is based on) signals are pretty robust. you could probably run DMX-512 over zip cord and it would work... as long as it was terminated properly.

    One of these days I'll post the 'scope traces I got at various points on the cable, both terminated and un-. It's pretty interesting to actually see the effects of reflections on the signal.

    John
     
  16. ship

    ship Senior Team Emeritus Premium Member

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    I'll confirm the robustness of the signal. I have some self coiling shop light spools of it in service. Self realing shop lights that you normally pull the cord to and you have the light fixture hook where you need it. In this case, I replaced the wire with a high grade microphone cable and used the power transfer brushes and ground to carry the signal. Works like a charm as long as you remove the self coiling locks on the real or they won't self coil. Grease used for electrical brushes, the brushes not in more than physical contact with the pad surface, much less it's not shielded as per Protocol and that shield is now part of the ground system for the lighting grid, it still works fine - given it's only a 25' spool.

    Often it's said that longer lengths of DMX signal will have problems. In DMXtools test, that was not the case but I'm sure it would not be on a long length something he would chance givne the budget to do better. I usually say that you want to go with at least a digital quality Microphone cable for the digital signal of moving lights. That's fair. For details, I trash any cable that is not at least a tinned wire braided if not having a foil shield plus a braided one.
     
  17. Mplunket

    Mplunket Member

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    thanks guys, i've been reading a lot about how exactly all this works, and i think i have a pretty good idea. we were also thinking of getting like 4-8 par cans to throw in the setup as well. so my understanding is, we run the par cans through a dimmer, and then run the dimmer into the dmx-40? and then we can control all the lights through the controller?
     
  18. Mplunket

    Mplunket Member

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    ok... i checked out ebay...found 6 par 56's for $25..pretty good deal. one question-- if i have 4 intelligent lights (and the board i'm gonna get says it can support 12 intel lights with 16 channels each), if i just put pars in it, is that going to count as much as an intelligent light, or is my board able to hold more pars because they require less information? sorry if that's not clear, hopefully someone can answer me ;-) thanks
     
  19. DMXtools

    DMXtools Active Member

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    Right now, I'm running 4 intel lights (American DJ PocketScans), 24 PAR cans, 3 strobes, 3 simple on-off effects (American DJ GEMs - multi-beam thingies that go roundy-round), two flame effects (fan makes a piece of silk flutter in the beams of orange and blue spots), and fourteen pinspots (...and a partridge in a pear treeee), all on an American DJ DMX Operator - identical to the Chauvet DMX-40... and I'm using less than half the available channels.

    An intel effect can use up to 16 DMX channels (the PocketScans only use seven, so I can double up), but each dimmer channel uses a single DMX channel. I map the first intel as "scanner 1 page A" - that's DMX address 1-8. It only uses 7 of the channels, but I've got plenty to spare. The second intel is "scanner 1 page B" - DMX address 9-16. The third is "Scanner 2 page A" - address 17-24 and the fourth is "Scanner 2 page B" - address 25-31. Some of the simpler Chauvet scanners only use 4 DMX channels - you could put four on one of the DMX-40's "scanner" buttons.

    Now comes the fun part. At the left side of the stage, I have a tree with an 8-channel dimmer pack. It gets mapped to DMX channels 32-40 - "Scanner 3 page A." Six of the channels control six of the PARs, one controls a strobe and one controls a flame effect on top of the left speaker stack. An identical setup on the right side of the stage gets mapped to DMX channels 41-48 - "scanner 3 page B."

    At the rear of the stage is yet another 8-channel pack mapped to channels 49-56 - "Scanner 4 page A" - that does 8 of the pinspots - two rows of four, pointed out over the heads of the audience at various angles. I can chase them - looks really neat in fog or haze. Also at the rear is a four-channel pack mapped to channels 57-60 - the bottom 4 faders for "scanner 4 page B" - that controls the third strobe and the three roundy-round effects, all positioned to backlight the band. A final four channel pack on channels 61-64 - the top half of "Scanner 4 page B" - does the remaining pinspots, all on one channel and aimed at my 24" disco ball from different angles and in different colors, and three groups of four-per-channel 150W PAR38's set up as footlights across the front of the stage. They're set up with red, green and blue gels - all the reds on one dimmer, all the green on another and all the blue on another. Physically, they're grouped as four clusters of three lights, one of each color - lets me do some crude color-mixing to get other shades.

    Anyhow, with all those lights, I've only used up 1/3 of the available DMX channels out of a DMX-40. It's a controller I'm really familiar with, so I'll be very happy to answer any other questions about it.

    John
     
  20. Mplunket

    Mplunket Member

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    that's great, i just wanted to know how many channels the pars would take up going through the dimmer. this makes me happy ;-) I found a site called High Energy Lighting. has anyone had experience from them before? good/bad? they have some pretty good deals on their with their gift cards, so i was going to buy a lot of stuff from there ;-). anyways, thanks for the help, i feel like i'm "getting" this more and more every day! I think my setup is going to be:

    -4 Chauvet Omega Intel. Lights
    -DMX-40 DMX-512 Lighting Controller
    -2 DMX-24 4 Channel Dimmer Packs
    -8 Par 38 cans
    -Chauvet Portable Truss System (w/ tripods on either end)

    whaddya think?
     

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