Edition 7 of “This May Be a Dumb Question, but…” – Audio 101

Blog Series written by Exertis Almo's Ashley Nichols, CTS, DSCE & John Borns, CTS, DSCE. 

Welcome to Issue 7 of “This may be a dumb question, but…”. This week, we’re going to tackle some basic questions with audio. This should be a fun one since neither of us would really call ourselves “audio experts.” Luckily, we have a whole team of audio experts on staff at Exertis Almo who will tell us about all of the things we got wrong. 😅 We’re going to share the ways we’ve come to understand some basic principles of audio that we’ve gathered by asking some dumb questions. Below are two questions we hear most frequently from newbies (like us), so hopefully these basic answers will help you feel empowered enough to dig a little deeper and expand that audio knowledge!

QUESTION

What’s the difference between 8ohm vs. 70-volt audio systems?

ANSWER

We will start by saying this: One is not better than the other, no matter what you hear. They are made for different situations and require different levels of sophistication and wiring. This is where your “needs analysis” also comes in, because you can save yourself a lot of unnecessary work if you ask: Is audio the driving NEED of the space, or is it just adding to the experience? Do you need to be able to scale the system later, or cover large areas now? How many audiophiles7 will be in the room to tell you that you chose the wrong brand? All important questions. Here is a chart to help you get an ‘at a glance’ feel for which system could be right for you:

8ohm 70v
Flexibility May require larger changes to the system if you add/remove speakers Most flexible, can add/subtract a few speakers without issue typically
Sound Quality Best Just Fine
Cost Effectiveness Less Expensive More Expensive
Scalability Not ideal for large spaces/long distances Best for large spaces/longer cable runs
Ease of Install Straight forward wiring, less components Relatively easy but may require additional components that add to the cost, time, and attention to detail
Room Size Smaller Spaces Large spaces, multi zone, etc.

As I said at the beginning, neither of these are truly “better” than the other. Like all of us, they just shine brighter when they are used in the right space at the right time. In another episode, we would be happy to go over the wiring differences between the two in more detail, so drop a line in the request section if you think that would be beneficial to you!

QUESTION

What’s the difference between mic level and line level audio?

ANSWER

If you’re a seasoned audio veteran, this probably sounds like the simplest question possible. Well, for someone like me who broke into the industry selling cables, it took me a while to fully understand what the difference is between these, and when/how to work with each one. Phoenix blocksFor me, I was always looking for the connectors on the cables to give me some sort of indication as to what signal they were sending, and to a certain degree they do. An XLR mic cable is GENERALLY used to for mic level audio, but not always. In many cases, there aren’t cable connectors at all, sometimes there’s just PHEONIX1 block connectors. Anyway, it became clearer to me when I learned that they’re all pretty much the same signal just at different voltage levels.

  • Mic Level – I was absolutely floored when I first learned that mic level signals are the signal that is produced by a microphone. I know it sounds crazy, but it’s true. Anyway, microphones are sensitive and produce very low signals, usually measured in mVa (millivolts)2. This signal would not be strong enough to produce and audio signal that you could do anything useful or be able to hear at all.
  • Line Level – The mic level audio signal that we just mentioned will need an audio device to bring that voltage of that signal up to line level. I personally think that line level would be better referred to as “Do Stuff Level”, because this is audio engineers like “do stuff” with the audio signal. Mixing, processing, recording, etc. are all done at line level. Ask Tom Kehr and he will agree that we should start referring to this as the “Do stuff level”. These signals are stronger, usually measured in 1V (volt). Once the signal has been processed and has all of the stuff done to it, it’s ready to be sent out to an amplifier which will bring it to speaker level.
  • Speaker LevelGet this: this is the signal level used to power speakers. The voltage4 is much stronger than line level, usually measured between 10V and 100V. The power of this signal is strong enough to move the physical cones in the speakers to produce the sweet sounds of the Taylor Swift concert that Ashley couldn’t get tickets for (not for lack of trying).

lord of the rings analogySo, really, an audio signal is just like a little hobbit making a journey through Middle Earth. It leaves the Shire weak, but full of ambitions (mic level), it journeys through Middle Earth where it “does a bunch of stuff” (line level) before it finally reaches its final destination in Mordor (speaker), where it finally gets to dunk the ring of power into the fires of Mount Doom and achieve the righteous sounds of a fully produced audio experience.

Vocab Test Time!

Are these the most detailed definitions? No – we are not a dictionary, nor the AVIXA CTS Prep book. Will someone message us after still telling us how much we missed? Possibly. Will these get you a basic working knowledge of these terms and why they matter? 😄 We hope so. Plus, we are 99% sure one of these words will be on your kids’ back to school pop quiz!

  1. Phoenix Block – a.k.a. Euroblock, a.k.a. combicon, essentially a low voltage terminal block commonly used in mic or line level audio signals, but you can also see it in RS232 or RS485 control signals as well.
  2. mVa or Millivolts – one-thousandth of a volt
  3. Milli Vanilli – French-German R&B group that rose to fame and fell to infamy in the last 80’s-early 90’s.
  4. Voltage (E). – The difference in charge between two points, caused by the pressure that forces the current to flow. Voltage is measured in volts.
  5. Current (I). – The rate at which the current flows. Current is measured in amperes, which are also referred to as amps.
  6. Resistance (R). – The rate at which a material resists the current’s flow. Resistance is measured in ohms.
  7. Audiophile – A person with A LOT of passion and enthusiasm around high-quality audio experiences.

Thanks for Reading and Asking Your Questions!

Do you have more ‘dumb’ questions? Share your questions here and we will get you an answer.

Did you find this blog post helpful? Connect with us and #TeamExertisAlmo over on LinkedIn.

Ashley Nichols, Dir BizDev

Ashley Nichols | CTS, DSCE

Director of Business Development

Supported Manufacturers: Sony

John Borns, BDM

John Borns | CTS, DSCE

Services Development Manager – Central

Exertis Almo Professional Services

Behind the Panel: I’ve got the POWER!!!

This Video Series was recorded by Exertis Almo's Business Development Managers: 
Patrick Booth, CTS, DSCE, and John Borns, CTS, DSCE.

In this video episode of the “Behind the Panel” blog series, Exertis Almo BDMs Patrick Booth and John Borns sit down with MiddleAtlantic BDM, Blake Brubaker to discuss all things related to powering your AV systems.

Power distribution is key to running your professional audiovisual gear. No humms, no surges.. just clean, reliable power.

Middle Atlantic’s evolution of AV Power Distribution and Backup.
NEXSYS combines power distribution and power backup into a comprehensive and cohesive product platform, united by design – both internal and external.

Why are you plugging your AV equipment into anything else?

Did you find this video helpful? Connect with us and #TeamExertisAlmo over on LinkedIn.

Find more episodes on the Exertis Almo YouTube Channel.

Patrick Booth, BDM

Patrick Booth | CTS, DSCE

Business Development Manager

Supported Manufacturers: Legrand AV (SW, W, NW) – Chief, C2G, Da-Lite, Luxul, Middle Atlantic, Vaddio, Wiremold

John Borns, BDM

John Borns | CTS, DSCE

Business Development Manager

Supported Manufacturers: Legrand AV (NE, SE, MW) – Chief, C2G, Da-Lite, Luxul, Middle Atlantic, Vaddio, Wiremold

Edition 6 of “This May Be a Dumb Question, but…” – Connections

This Blog Series is written by Exertis Almo's Business Development Managers: 
Ashley Nichols, CTS, DSCE, and John Borns, CTS, DSCE.
Welcome back to another thrilling edition of “This may be a dumb question, but…”. Cables must be in the zeitgeist because we’ve received a bunch of questions around cables lately. Maybe it’s because of Pat Booth’s recent Behind the Panel blog post, or maybe his blog is just a symptom of the industry’s thirst for cabling knowledge. Either way, we’re going to attempt to assuage that desire for cable information by hitting on all the hot topics. Instead of our normal format in which we tackle two equally important questions, we’re going to put together a “dumb questions” guided tour to AV cables and why, when, where, and how to use them.

Now, before we get too into the weeds with ALL of the types of cable connectors in the world, I think it’s important to address that we’re only here to talk about AV cables today. We ain’t talkin’ power cords, ain’t talking data cables.

AV cables have been around for a long time, but they have changed quite a bit in recent years. For most of the history of the AV industry, it was necessary to run your video signal and audio signals on completely different cables. The old Red, White and Yellow RCA5 cables were at one time a groundbreaking evolution because they ran those signals in a more streamlined fashion. You probably still have some of these lying around in a drawer somewhere, and if you do, I can assure you that you almost certainly will never need to use them again. Let it go, it’s ok. It’s FINE. In fact, as recently as when we both passed our CTS tests (humble brag), 6 years ago, there was still a great deal of attention paid to the differences between composite 5.1, component 5.2, and VGA 4 video signals. This was all very necessary and important when the primary video signals we were using were analog signals, but with advances in technology, most of the video signals we deal with today are all digital signals. Thankfully, some very clever people figured out better ways to do things and we now have some simpler digital cables that we primarily deal with today.

DVI-D cable

DVI-D Cable

DVI (Digital Video Interface)1

DVI was the AV industry’s first main adopter of digital video technology. It came out as the digital replacement to the VGA4 cable, which carried analog signals and had many limitations.

VGA cable

VGA Cable

In fact, if you look at it, you can see the similarities. Both had the locking screws that professionals wanted. Similar to VGA, it only carried video signals, meaning you needed another cable to run audio. At the time, it could offer superior resolutions 3840 × 2400 @ 30 Hz, which was its main upside. However, because display manufacturers were slow to adopt this standard, much of its time with us was defined by trying to convert and adapt it to other analog systems that were still around. At one point, there was a lot of confusion around DVI-A, DVI-I, and DVI-D – it became too much for people to really embrace. Have you ever started a new office job and been given two monitors to set up, and the IT guy hands you this wild looking cable that has a bunch of little pins in a configuration you’ve never seen? You may have been looking at a DVI cable. This was many people’s experiences with DVI – not really knowing what it was or how it was different. I’ll admit, I had never heard of this connector type prior to my tenure at Legrand almost 10 years ago. It was certainly superior to ye ole’ VGA cable in terms of video quality, but it would soon be completely outmatched by HDMI or DisplayPort. Here’s why…

HDMI cable
HDMI Cable

HDMI (High-Definition Multimedia Interface)2

Though released in 2002, HDMI didn’t start showing its (inter)face on HDTV’s until around 2004. By 2009, it had largely taken over sales of the previous digital interface, DVI, and was created to be backwards compatible with DVI. HDMI caught on in the consumer world first, offering the ability to run both audio and video on a single connector. HDMI soon became the preferred connector on Blu-ray players and videos games, driving the need for more adoption from display manufacturers. HDMI also offered some new features like HDCP (which is content protection that prevents digital signals from being pirated) and CEC (which allows for you to turn on your PlayStation 5 and it will turn on your TV automatically), to name a few. Fast forward to today, and we are on HDMI iteration 2.1, which allows HDMI to carry up to an 8K signal at 60Hz, which is the best there is at the moment, even if we typically don’t see other devices or content right now that would require this. This is all well and good for the home consumer, but it doesn’t offer some features that the Pro AV world looks for, and that’s where DisplayPort comes in.

DisplayPort3

DisplayPort, which was created back in 2006, really shouldn’t be considered a competitor to HDMI. Think more Messi vs. Lebron; Both are great in their own space and could complement each other in a system while maintaining their status. DisplayPort was specifically designed to replace DVI and VGA in computer environments, which is why you often see DisplayPort on computers and computer monitors, and not HDTV’s in your home. DisplayPort’s key differences are that the connectors have a locking mechanism (similar to the old VGA and DVI cables). Additionally, DisplayPort has a cool feature that allows you to daisy chain between displays, which is very handy in video wall applications. Arguments on the superiority of DisplayPort vs. HDMI may have stemmed from back in 2009 when DisplayPort was already able to support 8k at 60Hz with DSC, or Display Stream Compression, which is nearly a decade before HDMI could do that.

displayport cable
DisplayPort Cable
*note: while the connector looks VERY similar to an HDMI connector, you will not that only one corner has the ‘notch’ while the other corner is a 90 degree angle2, indicating it is a DisplayPort cable*

As it stands now, HDMI is preferred for AV applications when traditional TVs and displays are involved, and DisplayPort is still the main preference for PC and gaming applications. There are many details and nuance we are overlooking, but this is the 40,000 foot view of the two.

Vocab Test Time!

Are these the most detailed definitions? No – we are not a dictionary, nor the AVIXA CTS Prep book. Will someone message us after still telling us how much we missed? Possibly. Will these get you a basic working knowledge of these terms and why they matter? 😄 We hope so.

  1. DVI – stands for “Digital Video Interface”. First on the scene in the digital video world. Mainly only still used in niche applications but helped paved the way for HDMI and DisplayPort. DVI had to walk so that they could run. The world just wasn’t ready for him.
  2. HDMI – stands for “High-Definition Multimedia Interface.” The de-facto standard for audio/video today. Many features that appeal to consumers. You have a ton of these in your house, you can probably get rid of a few, but they’re not hurting you.
  3. DisplayPort – stands for “DisplayPort.” Another popular digital connection. Primarily used in the PC based applications, featuring some specific professional features that HDMI lacks.
  4. VGA – stands for “Video Graphics Array,” previous video signal standard on projectors and monitors. The industry has tried to retire analog tech like this for over a decade.
  5. RCA – stands for “Radio Corporation of America” and was the company that designed the connectors that were used to transport composite and component signals.
    • 5.1 – Composite Signal: red/yellow/white connectors you used to connect your Nintendo to the tube TV
    • 5.2 – Component Signal: red/blue/green connectors that supported high definition, and you used to connect the first Xbox to your TV
    • 5.3 – Compartmentalize: How I deal with my personal issues. Let’s not explore that too deeply.

Thanks for Reading and Asking Your Questions!

Do you have more ‘dumb’ questions? Share your questions here and we will get you an answer.

Did you find this blog post helpful? Connect with us and #TeamExertisAlmo over on LinkedIn.

Ashley Nichols, Dir BizDev

Ashley Nichols | CTS, DSCE

Director of Business Development

Supported Manufacturers: Sony

John Borns, BDM

John Borns | CTS, DSCE

Business Development Manager

Supported Manufacturers: Legrand AV (NE, SE, MW) – Chief, C2G, Da-Lite, Luxul, Middle Atlantic, Vaddio, Wiremold

Edition 5 of “This May Be a Dumb Question, but…”

This Blog Series is written by Exertis Almo's Business Development Managers: 
Ashley Nichols, CTS, DSCE, and John Borns, CTS, DSCE.

If you’ve been following along with our blog series for the past few months, you may have been led to believe that the only questions we ever get are related to projection systems. Who could blame you? You’ve obviously read 3 straight issues of our critically acclaimed mini-series on projection (edition 2, ed 3, and ed 4). Well, I hate to break it you like this, but you’d be wrong. We get all sorts of questions – and maybe you shouldn’t go around assuming things so much. 🤣 Maybe we shouldn’t have dedicated 80% of our blogs thus far to 1 topic. 🤔 There’s no way to know for sure. Anyway… Today, we’re going to talk about AV racks! Another seemingly mystifying part of the AV ecosystem that we’re going to try and make sense of for you.

QUESTION

John, Are these rackshelves/lacing bars/drawers compatible with my rack?
or… John, I have 8 pieces of gear. What size rack do I need?
or… John, How do I know if these pieces of gear will fit in my rack?

ANSWER

These may appear to be different questions, but in actuality, they all stem from not knowing the same basic principles about AV racks. Questions like these are very near and dear to Ashley and me, because we asked a lot of these questions when we first started working together at Middle Atlantic Products many moons ago. We totally remember what it was like trying make heads and tails of how racks work and how everything goes together and what goes where. It wasn’t until a kind soul (shout out to Jason Pavia!) came along and totally bailed us out and taught us how everything works. The beauty about racks is that they are actually very straightforward because there are rack STANDARDs in place.

Firstly, let’s talk about the width of the rack1. Every rack (as far as I know) is 19” wide between the rails. So, anyTHING that wants to be rack mountable is going to conform to that width. Power strips, amps, shelves, mixers, you name it – they’re all going to be that width (or have some additional rack mount hardware that allows to it to cover that space). You pretty much never need to worry about whether or not something will fit into a SPECIFIC rack, because all racks are same size.

The second thing to know is the RACK UNIT2 (or RU as it’s more commonly referred to). A rack unit is always 1.75” high…but that doesn’t really even matter, because everything that is going to be mounted onto a rack must confirm to a solid RU measurement. So those amps, power strips, drawers, etc., that we mentioned above, are all 1 RU, 2 RU, 3 RU etc. So, knowing all of that, you can confidently assume that all of your rack mountable gear will fit in whatever rack you end up going with AND you can determine how tall of a rack you need by simply knowing how many pieces of gear you’re putting in there and how many RUs they occupy.

The last thing consider is the depth of the rack3. This is where the standards sort of dry up. The main thing to concern yourself with here is the depth of your DEEPEST piece of gear. You pretty much just need to make sure that it’s deep enough to accommodate that one piece, with a little extra room for cables and air flow. So, if you have a 20” deep UPS, you’ll probably want to get like a 24” deep rack.

QUESTION

How do I know which type of rack to choose? Wall-mounted? Gangable?
Why would someone need one vs the other?

ANSWER

I’ll admit that no one has asked me this question exactly, but it is an amalgamation of a general overwhelming feeling people have when trying to start looking for a rack. There are a TON of options out there and knowing which ones to use and when can feel intimidating at first. This is really where understanding the needs of the system and users is critical. Most racks are built with a certain type of application in mind. Let’s hit on a few of the common ones and why people would want to consider them.

wall-mountable rackWall-Mounted Racks – There a few different uses here. Mainly, if you have smaller rack need…something like 8-10 RUs….it may be easier to access the gear for use or service by having it hanging off of the wall at eye level. Bending down or kneeling to get to the gear can be an unwanted nuisance, especially if the gear is being accessed routinely. Additionally, maybe you want to keep the gear away from small people with bad intentions – kids. Wall-mounted racks are used in classroom applications. Also, simply having the rack secured to the wall can save space in some locations and may help keep a cluttered closet a little more organized.

Gangable5 Racks – This is really just a way of describing racks that can be fixed to one another in a row. If you’ve ever infiltrated a high security data center to get access to the heavily guarded corporate secrets, then you’ve undoubtedly seen a bunch of server racks “ganged” together. This allows for multiple racks to sort of operate as one larger unit, allow for cables to pass more easily between one another, save space, etc. Additionally, maybe you have a small system now, but one to potentially expand in the future. Getting gangable rack will allow your system to be scalable…to expand into a second rack down the line.

AV rack2-Post Racks vs 4-Post Racks – Generally speaking, in AV applications, you won’t commonly use 2-posts racks. These are typically used in network-based applications with thinner patch panels and lots of wire management needs. 4-post racks are sturdier and can handle heavier AV gear like your amplifiers, DSPs, Mixers etc. Also, 4-posts racks can be more easily built into larger cabinets, which gives them additional options that may improve your system. Speaking of which…

Other things to considerSecurity, thermal management, additional storage, etc. I’m certainly not going to be able to do these additional considerations justice. Racks that can have fully welded side panels, and lockable doors are much secure than those that don’t. Some racks are better equipped to manage the heat in the rack (which is critical to control if you want to preserve the life of your gear). Some racks have more room inside the cabinet, or can accommodate special accessories, making it much easier to mount small devices and power strips. Knowing which of these features are critical for your project will help guide you towards the right rack. Luckily, we’re here to help guide you if you need some help!

Vocab Test Time!

Are these the most detailed definitions? No – we are not a dictionary, nor the AVIXA CTS Prep book. Will someone message us after still telling us how much we missed? Possibly. Will these get you a basic working knowledge of these terms and why they matter? We hope so. Plus, we are 99% sure they will help you impress your grandparents when you reset their WIFI. 🤔

  1. Width of rack – always 19”, doesn’t matter the rack.
  2. Rack Units (RUs) – 1.75” per rack unit. Describes the height of a rack and rack mountable gear.
  3. How deep is your rack – Make sure it’s deeper than your deepest piece of gear.
  4. How deep is your love? – I really need to know…
  5. Gangable – Racks that can be easily connected together.

Thanks for Reading and Asking Your Questions!

Do you have more ‘dumb’ questions? Share your questions here and we will get you an answer.

Did you find this blog post helpful? Connect with us and #TeamExertisAlmo over on LinkedIn.

Ashley Nichols, Dir BizDev

Ashley Nichols | CTS, DSCE

Director of Business Development

Supported Manufacturers: Sony

John Borns, BDM

John Borns | CTS, DSCE

Business Development Manager

Supported Manufacturers: Legrand AV (NE, SE, MW) – Chief, C2G, Da-Lite, Luxul, Middle Atlantic, Vaddio, Wiremold

Edition 4 of “This May Be a Dumb Question, but…”

This Blog Series is written by Exertis Almo's Business Development Managers: 
Ashley Nichols, CTS, DSCE, and John Borns, CTS, DSCE.

Welcome to our 4th and final issue focusing on projection topics. The most commonly asked questions we receive to have do with determining screen size, throw ratio, and brightness. We’re going to attempt to tackle those here today. To get here, we first wanted to make sure that you were knowledgeable enough to be dangerous when it comes to picking out screens and determining which TYPE of projector you need. If you’re coming in late on this, see our previous posts – edition 2 or edition 3WARNING: This may take a teensy bit of math, so get out your scratch paper!

FIRST UP: We need to understand aspect ratio.(1)

Simply put, aspect ratio is the relationship between the width and the height of a screen. It’s critical to know this so that we can ensure that the shape of projected image fits neatly within the screen. Every projector has a native aspect ratio, so ideally, you can pair a screen and projector with this information. Fortunately, this isn’t too much of a challenge, as MOST modern professional projectors can be programmed to support all sorts of aspect ratios. Why is this? Basically, the projector needs to be able to support anything you plug into it (computers, Blu-rays, you name it). Additionally, projectors don’t have the same lifespan as screens, so it’s very likely that you will need to match a new projector to an old screen. If someone took down the old projector and punted it into the sea before you had chance to know what it was, you can confidently install a new projector and trust it can adapt to the screen. Below are some common aspect ratios, and more specifically, the most common aspect ratios you will see in projection are 16:9, 16:10, and occasionally still a 4:3. The others are more commonly seen in LCD’s, gaming monitors, IMAX, etc., so we will ignore them for now.

ASPECT RATIO POSSIBLE RESOLUTIONS OTHER FORMS YOU WILL SEE
32:9 3840×1080, 5120×1440, 7680×2160 DFHD, DQHD, 32:9, DUHD
21:9 2560×1080, 3440×1440, 3840X1600, 5120×2160 21:9 Ultrawide
16:9 1280×720, 1366×768, 1600×900, 1920×1080, 2560×1440, 3840×2160, 5120×2880, 7680×4320 HD, FHD, 4K UHD, 8K UHD
16:10 1280×800, 1920×1200, 2560×1600 WUXGA, WXGA, WQXGA
4:3 1400×1050, 1440×1080, 1600×1200, 1920X1440, 2048X1536 XGA, SDTV

*Note: ‘other forms’ does not encompass all possibilities, just some of the most common forms

To calculate Aspect ratio when you aren’t sure what you have, the formula is Width divided by Height (W/H=AR). For example, pretend you have a screen that you measure and it is 125” wide by 70” high. 125” divided by 70” is 1.777. BEFORE you say, “Ashley, that is NOT on this list of aspect ratios!”— here is a handy tool to convert to nomenclature that is more common:

ASPECT RATIO ALSO ASPECT RATIO
16:9 1.78:1
16:10 1.6:1
4:3 1.33:1
21:9 2.33:1

These calculations MEAN the same thing: for every 16 units wide, there are 9 units high, or for every 1.777 units wide, there is 1 unit high. If you’re using an old fashioned calculator on your desk instead of some of the calculation tools out there on the World Wide Web, then you will see these decimals and can easily convert over to the more commonly used terms on the left.

SECOND UP: Throw ratio.(2)

Why do you need this? Well, if the aspect ratio is making sure you have the right shape of screen, the throw ratio will help make sure you have the right lens on the projector in relation to where you are mounting it, so that your image fills the screen to your liking. To calculate the throw ratio, you divide the distance from the projector by the width of the screen (D/W=TR). For example, you have 10.42 ft wide screen and you are mounting this bad boy 15ft away, you take 15ft/10.42ft= 1.439. Your throw ratio is 1.44:1, and you find the lens that fits that.

An important reminder is to make sure that you convert feet to inches (or vice versa) when doing your calculations. I’m commonly ask to recommend a screen for 125” wide screen that’s being mounted 15’ away. It would not look great for me to recommend a 1875:1 lens here – which is what you get if you don’t convert 15 feet into 180 inches. More commonly, I get requests such as, “I want to use XYZ projector, I have 164-inch diagonal screen and am mounting this 15ft away: which lens do I need?” I don’t know the width, but I do know the diagonal, so I can either ask for the width to be exact, or I can head over to this tool: http://screen-size.info/, pick out the Aspect Ratio, and find the width. If they give you another bit of info, like the height, then you can dig in the recesses of your brain and use the Pythagorean Theorem to manually calculate the width, but around here, we work smarter, not harder, so feel free to use the cheater tool.

LAST, not least (& probably the most difficult to calculate): How bright do I need my projector to be?

Why do I say this is harder to calculate? Because there are a lot of different variables in the room that affect the ability to see an image, and also, it’s subjective. If you have great eyes and can see the image just fine but someone who struggles a little more can’t make out the details, then that projector probably isn’t bright enough for the space or is even too bright (see Washout from edition 3), even if you think it is fine. There are general standards out there that can be adhered to, though, so we will go over those here briefly and you can build on that knowledge later with more research, if you want. If you read editions 2 and 3, then you have heard us say that projector brightness is measured in Lumens. You may see ANSI Lumens or Center Lumens, and these can be different numbers. Why is this? ANSI Lumens are defined by the American National Standards Institute, and “measures the overall amount of light the projector delivers.” Center Lumens just measures the “center spot,” which is likely the brightest spot on the screen, since no projector can deliver uniform brightness across the entire screen, so “center lumens” is likely a higher number than ANSI lumens. I wouldn’t say that one is better than the other, and neither can the industry at large, because you will see different people duke it out over why they prefer one to the other, but just note that they are different.

Ok, so, where am I going with this? You just want to know how bright the projector needs to be, and I’m giving you a vocab test. Well, bear with me, because here is one more term that I need you to know, and that is Foot lamberts. 👣 Yes, this is a real term. Once you’re finished chuckling, here is why you need to know what they are: these help you determine if the placement of your projector creates a viewable image in your room. By following these guidelines, you can determine if you are going with the 5,000 lumen projector or the 7,000 lumen projector. To do so, the formula is (Projector Lumens ÷ Screen Area) x Screen Gain = ftL

FOOT LAMBERTS AMBIENT LIGHT EXAMPLES
16 – 29 Dark Room Home theaters
30 – 39 Low Ambient Light Darkened rooms, no windows, etc.
40 – 59 Medium Ambient Light Classrooms, well-lit conference rooms
60+ High Ambient Light Auditoriums, lecture halls, etc.

The previous chart will help you determine if you are in the right ball park for brightness. Let’s pretend you have a 220” screen with 1.0 gain (see edition 2 where John talks about screen gain) in a lecture hall, and you got a great deal on a 7,000 lumen projector. Will it work? (7,000 lumens / 150sq.ft ) x 1.0= 47 ftL. Assuming the auditorium is well lit and has a lot of ambient light, this is probably NOT a good fit for the space. Something in the 9,000 lumens or more range would be better suited because it is 60ftL or more.

There are handy calculators out there on the web to assist you in this math so you don’t have to keep doing it yourself, but the next time someone comes to you asking for a suggestion, if you have bits of this info, you can help narrow down their search, and more importantly, be the hero!

Vocab Test Time!

Are these the most detailed definitions? No – we are not a dictionary, nor the AVIXA CTS Prep book. Will someone message us after still telling us how much we missed? Possibly. Will these get you a basic working knowledge of these terms and why they matter? We hope so. Plus, we are 99% sure they will help you shave a few strokes off your golf game. ⛳

  1. Aspect Ratio – the relationship of the height and width of your image (i.e. 4:3, 16:9, 16:10). Essentially, describes the shape of the screen.
  2. Throw Ratio – the relationship of the distance from a projection screen and the width of the screen. If you have these two pieces of information, you can easily calculate your throw ratio to determine which projector lens you need if a manufacturer doesn’t have a lens calculator on their website.
  3. Foot lamberts – Yes, this is a real measurement. Essentially, it is a unit of measurement used to determine how bright you need your projector to be. If you want to get more technical, it is equal to one circular candela per square foot (if this seems like a silly term, take it up with the Society of Motion Picture and Television Engineers who use it).
  4. Frank Lambert – Patriarchal figure in the Emmy Winning show ‘Step by Step.’

Thanks for Reading and Asking Your Questions!

Do you have more ‘dumb’ questions? Share your questions here and we will get you an answer.

Did you find this blog post helpful? Connect with us and #TeamExertisAlmo over on LinkedIn.

Ashley Nichols, Dir BizDev

Ashley Nichols | CTS, DSCE

Director of Business Development

 

Supported Manufacturers: Sony

John Borns, BDM

John Borns | CTS, DSCE

Business Development Manager

 

Supported Manufacturers: Legrand AV (NE, SE, MW) – Chief, C2G, Da-Lite, Luxul, Middle Atlantic, Vaddio, Wiremold

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