Factors to Consider When Designing an RGB Pixel Matrix

Over the years we at HolidayCoro have been asked why we only sell a single pixel matrix product - our 18" x 24" pixel with either 150 or 162 pixels.  Well, actually, we've produced a fair number of custom matrix based panel items for customers over the years and the main reason we don't offer all these variations for sale is because each project is so different.  The article hopes to provide information on factors that we consider when working with customers on designing a pixel matrix and hopefully this will help those building their own or working with us to custom produce one.

• What exactly is the purpose of the pixel matrix?
• Is this matrix intended to be dense enough that viewers will be able to see objects scrolling or displayed on it such as text, icons or logos?  
• What is the viewing distance from the matrix to the viewer?  If you've ever looked at a big screen TV up close, you can understand the relationship the size of the pixels (lights) have to the distance they are being viewed from.
• What is the viewing angle?  A curve pixel panel (such as a pixel megatree) can look odd if all the pixels in the matrix are not visible to the viewer.
• What is the shape of the matrix?  Is the matrix a cone, in the case of a pixel megatree, where the pixels at the top are in a much higher density than those at the bottom of the tree?  Is the matrix cylindrical?  flat? concave or convex?  All these designs have an effect on the final output, pixel density and mounting methods.
• Technical factors to consider include:
• Number of pixels - This is an important factor to consider and the number shouldn't be random - it should be based on the design requirements.  Look closely at how many pixels you'll need and their spacing from each other.  If needed, build a sample mock-up and view it from the distance and angle you expect your viewer to view it from. 
• Pixel height and width - Also consider how many pixels you may need to display certain items such as a text font which often require a 5x8 pattern.  Again, keep in mind that you will also need to have the pixels close enough that the human eye can make out the pattern - just because it might look good in the sequencing software doesn't mean that will translate into the real world.  
• Multi-Panel Alignment - If the matrix will be comprised of several panels, be sure to carefully consider the spacing within a panel and how it relates to the spacing induced between two adjoining panels.  This may mean that you will need to increase the center-to-center spacing of the lights to match that of the panel-to-panel gap.
• Mounting or support - An important part of any matrix is how you will mount it - because a matrix tends to be a flat area (excluding pixel megatrees), you'll need to think hard about what system you'll use to mount the substrate on to which the pixels are mounted. If that surface catches the air, there could be problems with it blowing over or toppling the support structure.  Also consider that you'll need to store this mounting system in the off-season - so if the panels need to go into an attic, consider the opening going to the attic.
• Substrate mounting - In most cases, you'll need to mount your pixels to a substrate - not only to support them but to maintain a clean and even spacing - there isn't anything worse than a matrix that has mis-aligned pixels.  How you mount those pixels can vary - it could be holes in coro like we do at HolidayCoro or it could be screwed or glued to wood slats or plywood - this all depends on your pixel type.
• Pixel type - The type of pixel you select will often be a by-product of the distance and viewing angle of the people viewing your matrix.  These pixels could be in a strip form, node form or module form and each has it's pros and cons and there is no one pixel that is best suited for all matrix types.
• Channels - Keep in mind that you'll often have many, many DMX channels on a matrix display and it makes sense to select pixel counts that fall within a set number of DMX universes - so don't design a pixel display that requires 180 pixels (18 wide by 10 high) if it could have been done in 163 pixels (18 wide by 9 high) which fits neatly into a single DMX universe and thus saves you a controller or controller output and also makes your sequencing easier to setup and manage.
• Repairs - Factor in that pixels DO fail and that you'll need to fix them.  So consider how easy it will be to remove and replace pixels.
• Cost / Budget - A matrix can grow in cost quite quickly when you factor in hundreds to thousands of pixels, so be sure to ask yourself the overall value of the matrix and how well it accomplishes its goal.  If this is just for announcing the radio station and song titles, a simple matrix will do - if you need to scroll logos or animations, you'll need a larger and more expensive matrix.
• Big isn't always better - Since pixels have come down in price and complexity, we've seen a number of pixel matrix panels (and pixel megatrees) in displays that just completely over-shadow and "hog" the display.  We believe that a well balanced display should be the ideal and that one mega-element can leave your audience so fixated on one area that they fail to see other areas and animation. 
• Software & Sequencing - Building a matrix panel is only one part of the process and the other major part is generating the sequencing for that panel.  Since it is nearly impossible to "hand" sequence matrix displays, you'll want to consider xLights, which has matrix effects, scrolling text, pictures and video built in.  You may even want to design your pixel display hardware, then start sequencing it before you buy or build it to evaluate how complex it will be to sequence the matrix. 

The Nearly Famous RGB Video Series - Everything You Wanted To Know About Pixels But Couldn't Find The Answer

When I started researching RGB and pixel solutions in early 2010, there was just about no information on the internet as to what all the teminolgy, protocols, wiring, controllers and other items were.  After extensive research and work with others, I decided to document all the information I knew at the time in the form of a video series.  The focus behind the videos was to simply show each type of lighting, controller, wiring, etc in a non-vendor specific manner so that someone just getting started out could get up to speed on the terminolgy and functions.  This information, while produced in late 2010, early 2011 is older now, every bit of it is still completely relevant.  Since this information is squirrled away on our website, I though I would repost it here for those new to RGB and pixels.

The videos below cover the general topics of RGB as they relate to Holiday Lighting.

Video #1 What is RGB? What are the different type of RGB lighting devices? What is Basic RGB and RGB Pixels? How to Pixels get their addresses? How do you assign channels to pixels? What are controller macros?
Video #2 How do I fix dead pixels? What is the difference between three and four wire pixels?  Does it matter? How do I know which end of my pixels to hook to the controller?  Does it matter? How do I power my pixels? Why are there different voltages for pixels? What is the difference between centralized and de-centralized power distribution of pixels? How many pixels can be on a single controller output? What is color depth in pixels?  Why does it matter?
Video #3 What are the different type of pixel chips? What quality issues should I be aware of when purchasing pixels? What are the drawbacks of RGB over just regular Christmas lights? What advantage do Basic RGB and RGB Pixels give me?
Video #4 What are the different types of Basic RGB controllers? Why would I want to use basic RGB controllers and LEDs instead of pixel based controllers and LEDs? What are the different types of RGB Pixel controllers?

Outlining Your House in RGB Lights - Detailed Design Guide (Updated for 2026)

Updated September 2026. We rewrote this guide around the pixels, mounting and controllers we recommend today. The original 2013 version was built around pixel strip and hardware that has since been replaced.

When you're planning a Christmas display, it's easy to focus on everything going in the yard. But the biggest prop is already there: your house. Outline it, and the house becomes part of the sequence, framing everything you've built in front of it.

Vineyards Lights, Meridian, ID. The rooflines, peaks and garage all become part of the show.

If you want the big picture first (why a mounting system matters and how to pick between seasonal and permanent), start with our house outline primer. This post is the step-by-step design: how to measure, how many pixels you need, how to power them and where the controller goes.

Would you rather have us do the math? Fill out our project design form and we'll send you instructions for sending us one photo of your house and your measurements. We'll put together a recommendation and a complete quote with the controller, mounting, hardware and accessories for your project.

Step 1: Start with a photo

Go outside and take a photo of your house from where your audience will see it, usually the street. You'll sketch your design on this photo and use it to record measurements, where cables will run and where the controller and power supplies will go.

We'll use Nathanial R.'s house as our example throughout. It has 19 separate rooflines, so it's a good example of how a house with complex roof lines can be handled.

Step 2: Measure every run

Get out the ladder and tape measure and record the exact length of every section you want to outline. Write each one on the photo.

Accuracy matters. Every foot you miss is another 4 pixels at 3 inch spacing, which changes your pixel count, your power budget and possibly how many controller outputs you need.

Step 3: Choose seasonal or permanent mounting

Across a whole house, mounting pixels one at a time means a lot of clips, a lot of alignment and a lot of visible black wire. A mounting system lets you build the outline in sections that hold their spacing and aim, snap into a few clips and come down as a unit for repairs.

Want it to come down after Christmas? Use Pixel Pipe. Each aluminum pipe is 7.3 feet long with 88 holes on 1 inch centers, sized for standard 12mm bullet pixel nodes. It's available in black, white or mill-finish grey, mounts with clear, UV-resistant clips that can stay on the house year-round, and rotates in its clips so you can aim the pixels toward your viewing area. Couplers, corners and tees let you follow the roofline.

Want it to stay up? Use PixaTrack. Each track is 6.66 feet long with 80 holes on 1 inch centers and takes 12mm bullet or square-neck nodes. It fully encloses the wiring to protect it from UV and animals, comes in off-white or brown to blend with the house, and is available with front-facing or side/down-facing holes.

Both come as samples, so you can hold one up against your house before you decide.

Step 4: Pick your spacing and count your pixels

Because both systems are drilled on 1 inch centers, you can space pixels at 1, 2, 3 inches or more by skipping holes. Two things set how far apart you can go:

• The wire length between nodes on the pixel string. Our 100-count 12mm node strings reach up to about 3.4 inches between nodes. For wider spacing, our 6 inch strings reach up to about 6.8 inches.
• The look you want. Closer spacing reads as a solid line and gives you more resolution for effects. Wider spacing costs less and gives a more classic bulb-by-bulb look.

The math is simple:

Pixels = run length in inches ÷ spacing in inches
DMX channels = pixels × 3

For Nathanial's house we grouped the 19 measured sections into four continuous runs and used 3 inch spacing:

Run	Length	Pixels (3" spacing)	DMX channels	Watts at full white
Garage front	26 ft	104	312	57
Garage, over the doors	34 ft	136	408	75
Front of house, upper	53 ft	212	636	117
Front of house, lower	31 ft	124	372	68
Total	144 ft	576	1,728	317

At 170 pixels per DMX universe, 576 pixels needs 4 universes. Any current E1.31 pixel controller handles that over a single network cable.

Step 5: Plan your power

Our 12v, 12mm nodes draw about 0.55 watts each at full white (45 milliamps). That's where the watts column above comes from: 576 pixels × 0.55 W = about 317 watts, or roughly 26 amps at 12 volts. Size your power supplies with headroom above that number, since draw varies with temperature, wiring and supply voltage.

The second question is how far the power can travel. As power runs down a string, voltage drops through the LEDs and the wire itself. Our 100-count node strings are designed to run the full 100 nodes with power fed at the start. Past that, plan to inject power. Three of the four runs above are over 100 pixels, so each would get power injection partway along, or be split into two shorter runs fed from separate outputs.

To inject, run heavier-gauge wire (14 AWG is a good start) from the power supply to the injection point and connect it to the power and ground of the string there. The data passes straight through, since each pixel regenerates it. See our guide to wire selection for sizing the injection wire.

Test before it goes on the house. Build a section, set it to full white for 15 to 30 minutes and measure the voltage at the controller output and at the last pixel with a multimeter. A drop of 10 to 20% is usually fine. Much more than that and you'll see dimming or color shift at the end of the run, or random flicker if the voltage falls below what the pixel chips need. Finding that on the ground is a lot easier than finding it on the roof.

Step 6: Place the controller

Look at your photo for where runs start and end. Places where two runs meet, like a garage corner or the peak over a front door, are natural spots to feed two outputs from one location. Current pixel controllers and sequencing software let you reverse a run's direction, so a run can start at either end.

The data signal from a pixel controller output only travels a limited distance to the first pixel, so you have two basic layouts:

• One central controller. An AlphaPix Classic with 4 or 16 outputs, placed somewhere central and close to the runs. It keeps everything in one enclosure, and spare outputs can drive other props in the yard.
• A controller plus long-range receivers. With a Flex system, the controller can sit in the garage and small long-range receivers go near the roofline where the runs start. This is the better fit for large houses, runs that start far apart, or when you want the main controller out of sight.

For Nathanial's four runs and about 317 watts, a single 4-output controller placed near the garage corner would handle the whole outline. Adding props later, or splitting the long runs, is where a 16-output controller or a Flex system with receivers starts to make sense. Our Controller Selection Wizard walks you through the options.

Step 7: Build and test on the ground

One of the biggest advantages of Pixel Pipe and PixaTrack is that you can build each section on the ground, plug it in and test it before it goes up. With connectors between sections, a problem later means unplugging one section, fixing it in the garage and putting it back without disturbing your spacing. With a seasonal install, the sections come down as a unit and go back up next year exactly as they were.

Watch the full process

Our house outline video walks through planning and building an outline with Pixel Pipe and PixaTrack from start to finish:

Let us put it together for you

You don't have to work out every part of the system yourself. Fill out our project design form and we'll send you instructions for sending one photo of your house and your measurements. We'll look at what you're planning and put together a recommendation and a complete quote with the controller, mounting, hardware and accessories you'll need.

Want to see the mounting in person first? Pixel Pipe and PixaTrack samples let you compare colors against your house before choosing a system.

HolidayCoro.com

The Good, Bad and the Future: Pixel Nodes



Channel Letter Sign with 8mm Pixel Nodes

8mm Tri-Color RGB Node with 12mm Case

First, a little background on the 8mm, tri-color LED node.  For anyone that has been to Asia (mainly China), you'll notice that they have many signs produced that use these nodes.  These signs are what we would, in the US, call Channel Letter signs.  In the US, we normally have channel letter sign that has an acrylic face with sheet metal sides and back that form a box, which is then illuminated with either neon (older) or LED modules (newer).  This channel letter design in the US produces a smooth clean, single color letter. 

While China also has the same type of channel letter signs, they also have the same sign but instead of an acrylic face they again use sheet metal for the face.  In that sheet metal they then punch ~12mm holes.  In these holes they install either dumb or intelligent RGB nodes.  This creates a sign that can be addressed either as a matrix (intelligent pixels) or just as a single color (dumb).  This type of sign design is nearly non-existent in the US currently.  So, why does this matter?  Well, this explains first why the physical case of nodes are generally 12mm in diameter.  It also explains why the little "fingers" that are on the side of the nodes are only about 1/16 of an inch between the top and bottom - they are design to fit into thin gauge sheet metal and pretty much nothing else. 

Here is the problem - they often are not exactly the same diameter, either from a single vendor, even within a single string or very often from vendor to vendor.  So you might have nodes with diameters of .40", .42", .44", .46" and so on.  So, if you want to make, say, a scrolling matrix panel (see sample panel video we've produced for a customer to the right) with pixel nodes. 

What we found is that when we produced these panels from ABS plastic, a hard, stiff plastic sheet, they would hold perfectly but only if you cut the hole with .01-.02" of the actual diameter of the node.  Any more and the node would either fall out or would be wonky and not point straight out.  Any less and it was impossible to get the node in at all - in fact many people had to use lubricant just to get some of the nodes in a string into the holes (which were all exactly the same diameter).  So, it was clear that if we wanted to sell a product that would hold and mount RGB nodes from any vendor, that we would need a different method of mounting them. 

At first this seems simple - just find some plastic that can hold them, right?  Well, it turns out that isn't the case.  In holding pixel nodes, you have a number of factors to consider:

• They need to be held tightly so as not to point different directions, causing different levels of light output.
• The material needs to be able to "adjust" to slightly different sized nodes from different vendors.
• The material needs to stand up to UV and a wide range of temperatures (-20 to 130f).
• The material needs to be at a cost point that the final product is reasonably priced.
• The material needs to be strong enough to handle 5-15 pounds of nodes.
• The material needs to be strong enough when mounted to a frame or other material to resist tearing, sagging, stretching or failing in high wind loads.
• And finally the material needs to be easy to machine on our CNC equipment.

It's a tall order and that's why we've yet to offer a "standard", non-custom mounting frame.  So, starting in February, we spent countless hours researching the tens of thousands of materials out there that could be a possible match for the magical material so we can bring products based on nodes to you.  As of March 8th, 2013, we have narrowed the field down to two companies that make very specialized plastics that meet our needs and we are working with them to produce and test the plastics that we hope will solve this problem.  We hope to have material in the April/May time frame after testing is completed and products shortly there after.

  

So, what do we plan to produce with this magical plastic?  Well that's a good question.  We know that lots of you out there want a method of creating a simple scrolling matrix screen like what is shown in the video above, so that's a pretty much no-brainier - we'll offer complete kits to build exactly that. 

We also plan to offer a mini-tree that also holds the nodes and is curved like a circular tree with the nodes "studded" through out - this would be offered as a dumb and smart mini-tree kit.

As is often the case, once we have a starter product, often customers are the source of some of the best ideas out there that we could never imagine.  So, if you have ideas for a product that incorporates RGB nodes, smart or dumb, feel free to email us or leave feedback below on the blog.

29-Mar-2013 - Update:  We have released the matrix panel here:  http://www.holidaycoro.com/Pixel-Matrix-Mounting-p/265.htm
 

Thanks,

David

HolidayCoro.com