What is an LED wall and how do they work?
LED walls have become the first choice for large digital displays thanks to their versatility, durability and vibrant full-colour graphics (and the fact that they’re becoming more affordable!) – but what is an LED wall and how do they work?
In this guide we’ll look at a what an LED wall is by looking at the components that make them up – so, LED tiles, cabinets, frameworks, media players and controllers.
We’ll explain how LED walls work, and what the pros and cons of using one are.
We’ll also clear up that all too common ‘LED screen vs. LED wall’ and ‘LED wall vs LED video wall’ confusion.
What is an LED wall?
Whilst an LED wall may look fairly simple, they’re made up of lots of different pieces of hardware. They contain five different types of components (excluding cabling) which are:
LED tiles and cabinets
The part of an LED wall that you can see is a series of lots of small tiles with LEDS (light-emitting diodes) embedded within them. They all clip together to create a seamless space for displaying your content.
The tiles are slotted into a special container called a cabinet to secure them into place. These cabinets are square or rectangular (usually minimum of 50cm²) and generally fit four, six or eight LED tiles within one cabinet (NB: LED tiles are usually sold as part of a complete cabinet, rather than individually).
Once the tiles are embedded within a cabinet they are then mounted onto an LED wall framework (we’ll come onto those shortly).
Most LED tiles and cabinets are designed to be easy to remove from the LED wall display so that, should any tiles or cabinets develop a fault, they can easily be removed and replaced.
LED wall framework
LED wall displays need to have a very consistent surface. Any small lumps or bumps on a wall’s surface will create inconsistencies that are very obvious when the display is switched on. So, a separate framework is usually used to securely position the cabinets into place on top of and alongside each other, creating a uniformly smooth surface.
An LED wall framework is a modular system that slots together (like a Meccano set) so they can be made in whatever dimensions you want and can be wall or floor-mounted. In addition to creating uniformity across the display, frameworks will also make the LED wall more robust and easier to service. (NB: Some LED tile/cabinet manufacturers say that some led tile products can be affixed directly to a wall without a framework, we definitely wouldn’t recommend doing this!)
Although frameworks must provide a consistent surface, that surface doesn’t necessarily have to be flat. This allows curved LED walls to be created by placing LED tiles on a curved framework. However, this is a very complex (and fiddly!) task and should only be attempted by experienced installers.
A media player is a small but powerful computer which is used to run your content management software and communicates with your LED wall controller, instructing it what to show. Usually you only need one media player per LED wall display.
LED wall controllers
LED wall controllers act like a translator between your media player computer and your LED wall display. They are used to convert data from your content management software into a format that the LED wall’s circuitry can understand.
Each controller can process data for a set number of pixels within a display. This means that large LED wall displays with a high resolution will need more than one processor.
How LED walls work
LED walls work in a similar way to a traditional television set, with each diode representing a single pixel. By controlling the RGB colour of these pixels, and viewing the display from a suitable distance, you can view the content. By changing the diodes’ colour several times a second (or switching it on and off), full-motion animation can be achieved.
This is all thanks to the LED wall controller, which transmits the data needed to constantly update each LED’s colour value (and on/off status) and change the image or video frame accordingly.
As with a TV screen, if you view an LED wall close up, you can see all the individual pixels that make up the images that you see, but view it from a distance and the pixels merge together to become a single coherent image.
With modern TV screens, you can choose the resolution you want (i.e. ‘Standard Definition’, ‘High Definition’, ‘Ultra-High Definition’). With LED wall displays, you have even more choice.
You can choose how closely spaced the diodes are in the display which changes the resolution and therefore how clearly defined the images shown are.
The measure of how densely packed the LEDs on a tile are, is called pixel pitch. It is refers to the gap between each pixel and affects how close up you can view the display, without seeing it as individual dots.
A lower pixel pitch means you can see the image from close range. With a higher pixel pitch, your viewing distance needs to be further away. A good rule of thumb is to take the minimum desired viewing distance and divide it by 1,000 to get the ideal pixel pitch. So, for an LED wall that will only be viewed from at least five metres away (5,000 mm), an LED pixel pitch of 5mm should be sufficient.
Pixel pitch is also important because the cost of a cabinet is determined by the number of diodes within it. This is because LEDs are relatively expensive in large quantities. For a large display that won’t be viewed at close range, you can use tiles with fewer LEDs which will cost less than those tightly packed with LEDs. However, if your display will be seen by people at a range of viewing distances, or if clarity is important, you’ll need to use a lower pixel pitch for your display which will be more expensive.
Why use an LED Wall?
So, what are LED walls used for? There’s a good reason these vivid displays are used for prestige locations like Times Square, Leicester Square and Piccadilly Circus. We’ll explain why here.
Key advantages of LED walls
The most obvious benefit is that they’re very vivid. This makes them stand out – even against other digital displays – and they’re easy to see from a distance. Furthermore, they don’t have bezels so they offer a seamless display, unlike a traditional video wall.
They don’t have a glass screen over the display, so they don’t suffer from glare from the sun or other light sources. This means that, unlike projectors and traditional video walls, they can be used outdoors and in very bright spaces and still be very easy to see (they’re even more vivid than high bright screens which are designed to be easily visible even in full sunlight).
Because they don’t have a set size or dimension and don’t have to be flat, they’re very flexible and can be used almost anywhere.
LED walls are made using lots of component parts, all of which (apart from the framework) are easy to replace, which means that once purchased and installed, maintaining them is fairly easy and cost effective. LED walls will generally last twice as long as a screen or projector.
Key disadvantages of LED walls
LED walls have several advantages over other large displays like video walls and projectors, and only one main key disadvantage which is the initial hardware purchase cost, though they are becoming more affordable as time goes on.
Whilst they are relatively energy efficient (compared to a standard, commercial digital signage screen of a similar size), they are still fairly power-hungry. The cost of running a large LED on an ongoing basis needs to be factored in.
Clearing up some confusion
LED screen vs. LED wall
There is a lot of confusion between whether an ‘LED screen’ and an ‘LED wall’ are the same thing. As the technology is still relatively new, different people within the industry refer to them using different names, which unfortunately adds to this confusion.
When we talk about an LED screen, we generally mean an all-in-one television-like display which is a type of LCD screen. The maximum size you can get for an LED screen (at the time of writing) is 110 inches (measured across the diagonal).
As we’ve already explained above, an LED wall (also often called a ‘dvLED’ or ‘LED video wall’) is made up of lots of different pieces of hardware. It has no set dimensions or sizes so it’s generally measured in square feet or square metres. The largest LED wall display in existence (at the time of writing) is 130,000 sq ft. However, an LED wall display could be as small as 1 square metre.
LED video wall vs. LED wall
As we’ve said, different people use different terminology in the digital signage and AV industry, and this context is probably the most confusing.
Most people have heard of the term ‘video wall’ and understand it to mean a large digital display. As a result, some people refer to LED walls as LED video walls.
However, you can also have a video wall which made using LED screens, and these can often be called an ‘LED video wall’ for short.
At Saturn, we try to avoid using the term ‘LED video wall’ for this exact reason because it could refer to either type of display.
Generally speaking, if you use the term ‘LED wall’ or ‘video wall using LED screens’, everyone should have a correct understanding of which type of display you’re referring to.
Potential pitfalls when buying/installing LED walls
LED walls are a compelling business choice thanks to their vibrancy, longevity and versatility, and they’re rapidly becoming more popular because of the various advantages mentioned above. However, there are pitfalls to be aware of when considering buying or hiring one.
The quality of LED tiles isn’t uniform, so the old adage of ‘buy cheap, you buy twice’ very much applies. Cheaper tiles are usually made with poor quality diodes which can result in inconsistent colours. So, if you were expecting to see a consistent red colour right across your display, it may appear pink-ish, purple-ish or orange-ish in different sections of your display. They’re also more likely to fail after a short period of time (which will leave your display looking patchy) so the tiles will need replacing. For the above reasons, always try to purchase your LED tiles from reputable manufacturers (e.g. LG, Absen, Hikvision).
As we’ve explained above, an LED wall involves lots and lots of different pieces of hardware being connected up, which is a pretty fiddly business. Subsequently it involves lots of time to complete. However, its likely to take much longer if it’s done by an inexperienced installer, which will delay the project’s completion and potentially cost more than initially quoted. And if it’s done badly, the whole thing could need to be taken apart and reinstalled. For these reasons we would always recommend using a reputable installer with plenty of experience with LED walls.
We hope this guide has helped to give you a better understanding of LED walls, but if you have any questions that we haven’t answered just drop us a line and we’ll be happy to help.
If you’d like to get a quote from us for the purchase and installation of an LED display wall, again, please just get in touch.
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