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DMX Hardware decisions...

Posted: Mon Oct 23, 2006 1:07 pm
by kevin
Hey all,

Not sure how many of you do any sort of light shows at halloween and christmas time. I am just getting started on Halloween, and after seeing this video last christmas with this house full of lights syncing to music, I was like "I need that".

So I bought a simple strobe light controller that activates to sound, and some cheap strobes. Bad mistake... read first! I did not realize that the strobes needed to be special 1/4" jack input strobes that cost about $50 a pop or more to be controlled. Anyway, I started looking into this more, and found that while you can control strobes with a $25 light controller and put a audio source next to it to simulate thunder and lightning... sadly, it's not very realistic. It will get the job done, but not quite what I wanted.

So, I found out more about DMX, heard about it a few years back for controlling in-home lights, but didn't realize it was used for all these big light displays at Disney and such. After some reading, there are a few choices that I can go with.

Because I am a software engineer, my first thought is any software I can run to control stuff with some device to output it to devices. Turns out there are a few free software titles, one is DMXControl, another is FreeStryder (I think thats it.. open source program). For about $60 you can buy a USB to DMX device that outputs up to 512 channels of control. More than enough for most home haunts if you have tons of lights, fog machines, etc.

The other option was to buy a light controller, something like the Chauvet DMX40a for about $120. I honestly don't know what is the better way to go. But here are some things to think about. First, for my realistic thunder and lightning show, you need a way to trigger the strobes first, then give a few seconds, then thunder sounds rolling out. But to be more realistic, you'd want a program that varies the lightning flashes and thunder sounds. For example, I'd want to play a very bright flash (from two strobes) then a loud thunder sound.. then a short delay and then some not too bright strboes, and a lower volume thunder and so forth. The biggest hurdle is... how to get DMX to trigger the audio of the sound. The only thing I can think of so far is that at least on the computer, both of the free software programs as well as the commercial ones offer MIDI triggers, so you can put a step to trigger a MIDI note that is then routed to your midi soundcard, and since most soundcards these days allow you to play sampled sounds, you run some cheap (or free) midi software that plays audio back on midi notes, and there you go... triggered audio. What I haven't found out yet is if there is some cheap recording device with DMX input that allows you to record some sounds and depending on the channel the DMX transmits on, play a sound. That would be ideal for those that don't want to lug a computer to near their DMX devices.

Another thing is.. fog machines, haze machines, etc. Sadly, the DMX versions cost a bit more. It seems that everything with DMX in it is a lot more expensive. I found a Chauvet 200-watt strobe with DMX that controls the inensity and triggers the strobe for $70 on one site, the same one for $200 elsewhere. The fog machines I bought have remote timer controls, but sadly there is no way to hook DMX into them, so you either have to buy a Chauvet fogger for about $200 or so with DMX in it, or buy a cheaper Chauvet and a DMX fogger controller for it.

So, if anyone has read this book and has some experience with DMX, I'd love to hear what your doing, what gear your using, etc. Is anyong controlling animatronic props with DMX... triggering them somehow as part of a show? Or are these things just sound/motion activated? Are there motion detecting DMX devices that you can plug in and when it detects motion.. run a series of DMX steps to animate/light different things?

The great thing about DMX is that you can also use it for christmas. With these relay packs (about $120 to control 4 sets of lights), you can turn lights on and off to music, fade them in/out, etc. I know this isn't a cheap route, but because you only use it once or twice a year, the gear should last a long time if stored properly and most software allows you to visualize what the light show will look like, although I have yet found anything that allows you to put in say a picture of your house as a background and then place lights and other DMX items over it to simulate where it would be for your house.

Posted: Tue Oct 24, 2006 10:15 pm
by MichaelMyers
I totally know what Christmas light show you are talking about...it was going around on the internet and it was AMAZING!! Sadly, the police asked them to turn it off because it was causing huge traffic jams by those peoples home. I would love to see it in person!