07.03.18

Letter from America: “Get the ‘LED’ In”

prototype of samsung the wall (featuring LED technology) on display at show

Anyone who has been in a PE or exercise class knows that when your pace begins to lag the teacher or instructor will sometimes feel inclined to yell “GET THE LEAD OUT!.” Always the contrarian, I’m going to turn that on its head this month and delete a letter in the key word to say “GET THE LED IN!.”

Yes, it’s a bit of a stretch, but you can look at “lead” and “LED” and somewhat pronounce them the same. We make the point here to not only recap some of what was observed at recent trade show and conference events, but to begin a series of regular “Letters” here that dive into the background of some key product topics.

I spent the better part of last month on the road, first at ISE in Amsterdam and then later in the month at the Hollywood Professional Association’s annual “The Technology Retreat” (TTR) is a somewhat warmer Palm Desert, California. The former is a mash up of residential, commercial and enterprise products and education, while the latter is a premier global gathering of the top engineers, technologists and executives on all sides of content creation, distribution and display. Two seemingly unrelated events, but they had one interesting thing in common: they were anxious to let “LED” in – at least in so far as displays are concerned.

Just to set the record straight, here we are taking “LED displays” literally. In other words, the typically large display systems with RGB LEDs facing out towards the viewer and built up in modules so that the size may vary. (This is NOT about the use of LEDs as the backlight to illuminate LCD displays. Advancements there will be the subject here later on in the year).

Samsung and Sony seek to lead the way

So what was all the buzz about? Let’s start with “The Wall”. That’s the name of Samsung’s 146-in diagonal, microLED-based, 4K/UHD, HDR that was first unveiled at CES. It was also prominently displayed at ISE, and it looked as good and wowed the crowds a much on one side of the ocean at it did on the other. Note that there were no additional specifics available at ISE about the exact pricing and availability date.

However, perhaps more important was another LED-based display from Samsung that I saw at ISE: Samsung’s Cinema Screen. Albeit shown only in private “backroom”, invitation-only demos, its appearance at ISE was a first for both Europe and North America. It must be said that the ISE demo was in a space, and in a size, that did not permit it be shown to its full capabilities. However, the demo, along with other information gathered at a key session at TTR puts direct LED products in the forefront for applications that are much closer than they were at this point last year.

Before going into the inner details of the Cinema Screen, and how it relates to the world of residential installations, the first thing to note is that this is not a microLED product, as The Wall and Sony’s Crystal LED systems are. It uses conventional direct-view LED modules where the pixel pitch is 2.5mm. If that may sound a big larger than some of the other LED systems at ISE, it is. That is part of the things that we’ll have to absorb when it comes to specifying larger direct LED systems.

Based on what was shown at ISE and elsewhere, pixel pitch can be as big as 10mm and as small as 0.8mm and even smaller. While it is natural to think that a 2.5mm pitch will mean low resolution, that isn’t always the case. The Cinema Screen at ISE was a 2K/Full HD system as it lines up against the competition from more conventional cinema projectors.

Doing the maths

Where the math comes into play is that the resolution for these systems is more than just the pitch, but the number of LEDs in each model and the number of modules in the completed system. The arithmetic behind requires more explanation than we have room for here, so the best advice is not only to educate yourself and your team, but to work with a very knowledgeable system supplier.

“Proof that small pitch alone does not guarantee high, or, just as importantly, standard resolution was seen by the many small pitch systems at ISE.”

Indeed, as they say in the disclaimers for “MPG”, “your mileage may vary”. Proof that small pitch alone does not guarantee high, or, just as importantly, standard resolution was seen by the many small pitch systems at ISE. Some were high resolution, some at approximately 4K, but the screen specs were often odd to those of us used to 3840x2160 or 1920x1080. A look at the pictures below shows that pitch, alone, does not equal standard resolution configurations. Yes, as needed you can scale to standard HD, 4K, or in some cases even 8K, but be very aware of any impact the scaling has on image quality. Caveat emptor!

Camellia LED 0.95mm and 0.95mm 4K comparison

Of course, part of your education in direct LED is definitely that wider pixel pitch does make a difference. Shown below are two comparisons at the same distance. Can you tell the difference? Of course… that is if you are up close! Will the viewers or audience be looking that the screen up close, as in a boardroom, corporate lobby or retail window? Or, will they be looking across the pitch or court floor at a stadium scoreboard or arena-edge runner display? As is always, the golden rule is “know your installation requirements and only then pick the right kit.”

led comparison ranging from 1.8mm to 10mm

So, where are we so far? First, not all large screens are microLED; given the application, standard direct view LED may be just fine – even for a cinema! Next, small pixel pitch alone, regardless of LED technology, does not necessarily guarantee high resolution. Then, when it does, the aspect ratio and resolution may not be to consumer standards. Finally, and most importantly, these LED walls are and will continue to be quite costly. Know what you are doing or consult a VERY knowledgeable expert, consultant, manufacturer or systems provider before you leap in. The alternative may not be pleasant.

One other issue regarding the use of large LED walls, particularly in cinema or home applications has been the problem of creating an accurate sound field. In more commercial situations the use of side-mounted speakers, or in large venue installations large line arrays, is sufficient. However, when the system requires multi-channel, accurately localised sound, to date there has been a problem.

As we all know, for large cinema or home screen situations, the use of a perforated screen with speakers behind it for the LCR is well known. Great, but what do you do when the screen is solid? Based on the Samsung demo at ISE and a superb presentation at TTR cleverly titled “Projecting the End of Projection,” some the solutions were detailed.

“Harman’s 'De-elevation Technology' allows the LCR speakers to be physically placed above the screen while the listeners think that the sound is coming from behind the screen.”

Remembering that Samsung is now the owner of Harman, and thus the parent company of JBL, it should come as no surprise that the descendants of the creators of the sound used for the first “talkies” would figure it out. Thanks to some very sophisticated DSP technology and speaker design, Harman’s “De-elevation Technology” allows the LCR speakers to be physically placed above the screen while the listeners think that the sound is coming from behind the screen.

Other technology using DSP and specially placed speakers have been developed by Meyer Sound as well as by Procella Audio in conjunction with Finnkino. The latter system has already been installed in dozens of cinemas, some that even have a full object-based, Dolby Atmos system, again even though the speakers are above the screen and around the room, rather than behind the screen.

Other systems are being installed with LED walls that employ speakers configured to bounce off the screen, something the Harman system is also said to be using, as well as near-field monitors.

As is the case with virtually all of the LED video systems described here, the price for the audio side is likely to be, well, “If you have to ask you probably can’t afford it.” However, as with all things in the world of consumer electronics you can get (most of them) now for “cost is no object” clients while you keep aware of the technology and trends so you are ready for a broader rollout when the inevitable cost reductions occur.

For now, direct (and micro-) LED walls are still likely to be out of the range of most jobs, but the attention given to CLEDIS, The Wall and Cinema Screen will raise the technology’s visibility among your clients. It won’t be that soon, be perhaps sooner than you might think, that the contents of this Letter will be something you’ll begin to provide on a broader basis.

Michael Heiss is a technology consultant and journalist, CEDIA Fellow, CEDIA ESC 2 Certified, and US correspondent for HiddenWires magazine. You can contact Michael via the HiddenWires LinkedIn Group, follow him on Twitter @captnvid, or comment on his article, below.