Abdullah Yahya

Let’s say you have a bunch of songs and for each song, you want to have different colored lights come on and off and/or move around.

In order to do this, you need a few things:

• Light fixtures
• DMX Interface
• DAW (Digital Audio Workstation) software / controller

Light fixtures

There are different types of light fixtures.

Above are only some of the more common types of lights.

To hang your lights, you can get a lighting stand with T-Bar.

DMX Interface

DMX (Digital Multiplexing) or, officially, USITT DMX512, is a unidirectional serial data protocol, meaning the signal leaves the controller (computer or lighting board) and travels through all lighting fixtures in a daisy-chain. It was standardized in 1986. DMX networks typically only have one master device on the network, usually the DAW software / controller, and many slave devices — the lights.

DMX Cable

The 5-pin XLR the standard connector.

The reason for five pins is that pin 1 would be the ground, pins 2 and 3 would be data link 1, and pins 4 and 5 were reserved for data link 2 and/or proprietary data. Over the years, the second pair of pins (pins 4 & 5) on the connector stopped being used, since 3-pin DMX proved to be very reliable. This is why you may sometimes see fixtures with a 3-pin, 5-pin, or both connectors on the fixture.

DMX vs Audio/Mic XLR Cables

Some DMX cables are 3-pin cables. Don’t confuse them with 3-pin audio or mic cables. DMX cables use roughly 110-ohms whereas microphone cables are typically around 45 ohms. The different impedance between these cables matters with lighting networks and can cause your lights to either not respond or respond sporadically.

Number of light fixtures per DMX cable

You cannot have more than 32 devices connected on a single chain. If you have more than 32 light fixtures, you would need to use an Opto-Splitter. A splitter like the Chauvet DJ Data Stream 4 will allow you to have 32 devices connected to each DMX output connector. You cannot use Y-cables, as this approach does not electrically isolate the DMX lines and would cause data reflections.

DMX Channels / Universe

A DMX line is limited to a total of 512 channels, which is also called a universe. Each lighting fixture you have uses a number of DMX channels depending on how many parameters the fixture has. Lights can also have multiple personalities, or profiles, depending on how much or how little control you want. Note that the 512-channel limit is independent of the 32-light fixture limit.

Let’s say you have 40 lighting fixtures that use three channels each: you are only using 120 channels total. You can fit these all in the same universe of control, however, if you have more than 32 devices. You would implement an Opto-Splitter and split your devices up among the outputs in whatever configuration you would like, as long as each DMX leg has less than 32 devices on it.

Example

Let’s look at the Chauvet DJ SlimPAR Pro H.

This light has three different personalities, or profiles. It can be used in a 6-, 7-, and 10-channel mode, and again the more channels a fixture uses, the more control you have. Let’s look at 7-channel mode:

• Channel 1: Dimmer
• Channel 2: Red
• Channel 3: Green
• Channel 4: Blue
• Channel 5: Amber
• Channel 6: White
• Channel 7: UV

Each DMX parameter on a fixture operates independently. Say I was to make this fixture a magenta color. I would turn up channel 2 (Red) and channel 4 (Blue) until I got my desired shade of magenta. However, turning up just these channels on the fixture (2 & 4) would not put out any light. I would also need to turn up channel 1, which is my dimmer that controls the overall intensity. On moving fixtures, this control becomes even more complex, because there are other parameters available, such as Pan and Tilt or gobos, again all independent.

The best way to understand a light’s capabilities is by checking its DMX assignments. For example, the ADJ Starbust’s manual shows this.

Addresses

When setting up a lighting rig, each light fixture needs to be assigned a starting address. If I have four of the same fixture mentioned above in the same personality (7-channel mode), their addresses would be 1, 8, 15, and 22. All 512 channels of data flow through every fixture in a DMX lighting chain so each fixture needs to know which channels control it based on channel addressing.

DAW (Digital Audio Workstation) software / controller

There are many different DAW software, for example, Ableton Live and Pro Tools. They can be used to create music and control lights. This article isn’t about creating music but just controlling lights in sync with existing music. Therefore, the software we’ll use is Show Buddy.

Setup

To sync light effects with music (e.g. an existing mp3 file), we’ll use this setup.

• Laptop with USB interface
• Enttec DMX USB DMXIS 70570 with software – $300
  • USB to DMX Controller Interface to connect laptop to lights
  • DMXIS software to control lights / create light effects
  • Unlike cheaper USB to DMX interfaces, DMXIS has an on-board controller to generate data into DMX format which is much more reliable than letting the computer generate the data.
• Show Buddy software to sync light effects with music – $119
  • DMXIS light controller software is required to run Show Buddy
• Capture (Student Edition) – Light visualization software – Free
• 4 PAR lights – $90
• Cables
  • 1 x USB cable
  • Data grade DMX 3 or 5 pin cables, depending on number of light fixtures (not mic cables)
  • 1 x DMX terminator

Terminate the DMX cable chain by inserting a DMX terminator into the DMX Out port of the last light fixture.

DMXIS Software

Important terminology

• Show (group of songs)
  You can create multiple shows. A show typically is the name of a list of songs, e.g. Yanni Concert
• Bank (a song)
  You can create multiple banks per show. A bank can be the name of a song, e.g. Santorini
• Preset (a light effect)
  You can create multiple presets per bank. A preset can be the name of a light effect. You can create multiple presets (light effects) for a bank (song) in order of when you want the preset (light effect) to occur during song playback. You can drag presets up and down to order them.

Workflow

1. Add a light fixture
   If the light fixture you want to add isn’t in the DMXIS library, you can search for it at http://fixtures.dmxis.com/ where you can download user-uploaded DMX light fixes for importing into DMXIS. If you don’t find your fixture there, you can create and upload DMX light specs for your particular fixture. It is just a text file defining channel.
2. Assign each light fixture to a starting address, e.g.
   • PAR light 1 (3 channels) starts at DMX address 1 (channels 1-3)
   • PAR light 2 (3 channels) starts at DMX address 4 (channels 4-6)
   • PAR light 3 (3 channels) starts at DMX address 7 (channels 7-9)
   • PAR light 4 (3 channels) starts at DMX address 10 (channels 10-12)
3. Create a “show”, e.g. “Instrumental Songs”
4. Create a “bank”, e.g. “Santorini”
5. Create a preset, e.g. “Red”
6. Adjust the sliders for one or more light fixtures, e.g. by making them show red light
7. Save (overwrite) the “Red” preset
8. Repeat steps 4-6 as much as needed

Resources

• Documentation (pdf)
• Tutorial (video)

ShowBuddy Software

This software allows you to load audio files (e.g. mp3s) and for each song, place a preset (light effect) created in DMXIS at certain points in the song. Light effects can fade out over a specified amount of time.

Workflow

1. Add audio files (songs / mp3s) to the Track Library
2. Choose the DMXIS show to use in the DMXIS show dropdown
3. Choose a DMXIS bank to use in the list of banks
4. Choose a DMXIS preset to use in the list of presets
5. Drag the preset to the wave form at the point you want the preset (light effect) to run
6. Repeat steps 2-5 as much as needed

Resources

Capture Software

This software allows you to preview light effects.

Workflow

1. Create a 3D stage
2. Add one or more light fixtures to the 3D stage
3. Patch light fixtures (assign them to DMX addresses)
4. If the light fixture address assignment in Capture matches that in DMXIS, then DMXIS can control the light visualizations in Capture

Resources

1. Manual (HTML)
2. Create a stage and add a light fixture (Video)
3. Patch and control light fixtures (Video)

Some Neat DMX Light Fixtures

Magic Ball

Simulate a magic ball with these lights:

Chauvet DJ Rotosphere Q3. $300

• Size: 11 x 13 x 17 in
• Weight: 8.6 lb
• # of LEDs: 5
• Watt per LED: 7
• Color: RGBW (Red, Green, Blue, White)
• DMX channels: 3, 9, or 19
• Strobe Rate: 0 to 20 Hz
• Rotation Speed: 2 – 19 RPM
• Colors at a time: 3

ADJ Starburst RGBWA+UV LED Sphere Effect – $300

• Size: 12.5” x 12.5” x 16.25”
• Weight: 8 lbs
• # of LEDs: 5
• Watt per LED: 15
• Color: RGBWY+UV (Red, Green, Blue, White, Yellow & Purple)
• DMX channels: 12
• Strobe Rate: slow to fast
• Rotation Speed: slow to fast
• Colors at a time: 1

Moving Light Beams

Create a moving beam with these lights:

Lixada Moving Head – $71

• Size: 6.88 * 6.69 * 9.64in
• Weight: 6 lbs
• # of LEDs: 7
• Watt per LED: 10
• Color: RGBW (Red, Green, Blue, White)
• DMX channels: 9 or 14
• Pan/tilt: 540° / 270°
• Strobe Rate: adjustable
• Beam angle: adjustable
• Rotation Speed: slow to fast
• Colors at a time: 1

Wash

Wash walls or a stage with these lights:

Chauvet SlimPAR Pro.

Kebert Par Lights – $20

Blinders / Strobe Light

Create very bright white flashes of light with these lights

Blizzard SnowBlind™ and SnowBlind™ FX strobe fixtures. – $119

MFL S100 132LED White bright Stage Lighting Strobe Blinder and Wash Light – $88

Cost Breakdown

Light Fixtures

• 1 magic ball – $300
• 2 moving heads – $66 x 2 = $132
• 1 blinder – $88
• 4 PAR cans – $20 x 8 = $160

Subtotal: $680

Hardware / Software

• DMXIS – $300
• Show Buddy – $119

Subtotal: $419

Cables

• DMX 3 pin cables – 10 pack – $26
• 1 x DMX terminator – $10

Subtotal: $36

Total: $1135

Different Light Effects

Wall Wash

Regular

Laser / Pin Spot

Beam

Magic Ball / Disco

Moving / Scan

Blinder (super bright light)

Chase (lights turn on and off sequentially like dominos)

Strobe / Flash

Alternative Setup

If you’re on a Mac, an alternative setup is to use LightKey coupled with Ableton Live.

or SoundSwitch.

Here’s a quick intro to 3d modeling using SketchUp in the browser.

Note: you can use SketchUp online or using the downloaded app. The free version of SketchUp doesn’t support creating Bezier curves. For that and other features, you’ll have to upgrade to SketchUp Pro.

When we create a new SketchUp sketch, we see this screen.

Let’s say we want to make four posts for a pergola. The posts are 6″x6″x10′ tall (actual dimensions are 5.5″x5.5″x10′).

First, under Model Info, we set the length format and precision.

To create our first post, we choose the Rectangle tool.

We click once in the 3D space and drag to create a rectangle which is 5.5″ x 5.5″. When dragging, we see in the bottom right corner the dimensions of the rectangle.

Instead of dragging until you get the right rectangle dimensions, just type 5.5,5.5 and then hit Enter.

Now, to complete making the first post, we need to “pull” the rectangle (actually, it’s a square) up 10 feet. Click the “pull” button.

Then click the square and drag up.

Again, to simplify getting the right dimensions, just type 120 and hit Enter to make the post 10 feet tall. Since all measurements are in inches, we type 120 instead of 10. SketchUp then converts the 120 to 10′ in the Dimensions box in the bottom right corner.

To verify the dimensions of any side of the object, click the Select tool.

and then click a side, e.g. a long side of the post, and in the Entity Info panel, we see that the length of that side is 10′.

Now, we’ll copy and paste that post by selecting the entire post, hitting Ctrl+C and Ctrl-V, and clicking where we want the other posts to be.

Now, the 2nd post is clearly not lined up with the first so we have to move it. Moving objects in SketchUp can be confusing to new users. Here are some ways to move an object.

Moving an object against another object

Let’s say we want to move the 2nd post flush against the first post. First, we orbit the view, if necessary, and select all of the 2nd post.

Then, we click the Move button.

and click on one corner of the 2nd post that we want to touch a corner on the first post.

Then, we click on the corner of the first post where we want that corner to touch. Now, the posts are flush and lined up together with each other.

Moving an object along an axis to line up with another object

Let’s say the 2nd post is higher up than the first post. We want to lower it so that both are on the ground, so to speak. We want to move the 2nd post vertically along the Z axis down until its bottom is on the same plane as the bottom of the first post. To do this,

1. select the 2nd post
2. click the Move button and click the bottom left corner of the 2nd post
3. drag up and down until you see “On Blue Axis” which is the Z axis
4. hold the Shift key – you will see the tip “Constrained on line from point” which means your movements are constrained to the axis you were on (blue / vertical / Z)
5. while holding Shift, drag and click on the bottom right corner of the first post.

You can also constrain movements to other axes as well.

Moving by Coordinates

Using the dimensions tool, we mark the distance between the two posts along the green axis. We get 12′.

Let’s say we want the distance between them to be 10′ instead.

Relative coordinates in SketchUp are indicated as <r,g,b> or <red,green,blue> (the colors of the axes). So, if we want to move 2′ (24″) towards the first post (towards [0,0,0]), we can do this

1. select all of the 2nd post
2. click the Move tool and click the bottom left corner
3. drag a little anywhere to begin movement
4. type <,-24,> and hit Enter

Now, the distance between the two posts along the green axis is 10′.

Absolute coordinates in SketchUp are indicated as [r,g,b] or [red,green,blue]. So, if we want to move to the center of the coordinate system, we do the same as above except we enter [0,0,0].

Using the techniques above, we can make 4 posts that are exactly 10′ apart and all on the same red-green plane.