Resources

LED Wall - minimum viewing distance, a quick calculator

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We get a lot of questions about how to properly calculate the minimum viewing distance for LED video walls of specific sizes.  Here's an easy calculator. 

Take the video wall pixel pitch in millimeters, multiply by 3 and add 10%. 

For example, we'll use a very common 3.91mm pixel pitch wall panel.  3.91 x 3 = 11.73 + 10% is 12.9'. 

If you view the wall at any closer than about 13', the picture will appear to be very grainy.  The reason for this is that LED wall panels have relative low native resolution (a half-meter panel with 3.91 pixel pitch uses just 128x128 pixels), and it takes several individual panels to create a presentation display like you'd see in an auditorium or church.  A 4x7 grid of these panels will create an 80x139" display (about the same size as a 12' projection screen).  That display will have a native resolution of 896x512 pixels. 

I hope that helps you understand a bit more about minimum viewing distance.  If you have questions about LED video walls and whether they're a good fit for your application, please call us at 800-747-7301.

 

Free System Design Review

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You've undoubtedly asked yourself, "So what exactly does that mean? Free System Design Review.  The words were blocked in red in the advertisement, so I just clicked it.  And now what?" 

What that means is that we're here to help. 

If you're in the market for a new audio, video, lighting and/or projection system or upgrade (or are having problems with what you have), let us know. 

Do you have a proposal in-hand and aren't quite sure what to think of it?  We'll look it over and tell you what we think. 

Do you have questions about wireless microphones, HD video distribution for production and presentation, or on how to improve audio coverage on your auditorium?  These are things that we work with every day, and we'd be glad to provide some ideas. 

Do you have questions about video streaming, laser projectors, multi-site systems, or wonder about next steps as your church grows?  We've worked with one of our church clients from its start with 20 people to about 5000 weekend attendance today, and we can help with system design and equipment standardization.

Sometimes, you just need one more set of eyes (or ears) to solve a problem or to get confirmation of what you're already thinking. 

We're celebrating our 25th year in 2017, so we've seen a lot, and we've learned a lot.  If you think that our experience might be helpful to you, call us at (800) 747-7301.  Or you can send us some photos, a video, an audio recording, take us on a Facetime tour, or email us at gtsales@geartechs.com. 

Technology for Worship: It's what we do.

   

Block 96% of ambient light, without covering the windows

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We could spend all day telling you  about how Da-Lite Parallax screens block over 95% of ambient light from windows and and other light sources. We could describe how it maintains a bright, vibrant image even when a room is filled with natural light. We could thoroughly explain how it offers extremely wide viewing angles, with no speckle or glare. But we'd rather show you.

After all, seeing is believing. That's why Da-Lite created a video to show you the difference.

As you can see, the difference is striking. That's why if you have a brightly lit room, Parallax is the best screen choice for your project.  Please call us for more information on this amazing new screen technology. 

   

Feedback is not always bad.

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by Mike Sessler, ChurchTechArts.org

Audio guys are taught to fear and loath feedback. We have parametric EQs, notch filters, magic boxes and feedback eliminators, all to keep feedback from rearing it's ugly head. The mix could be great, the lighting perfect and the song words spot on, but if the pastor's mic runs into feedback, you feel like you've failed. For most of us feedback=bad.

But Is It?

The feedback of which I speak in the opening paragraph is of course, the electro-acoustical kind. The mic picks up it's own signal, it goes through the amplification loop and repeats, ending in a high-pitched scream. And I agree, that kind of feedback is bad. But not all feedback is. In fact, sometimes, feedback can be very helpful.

Getting Better All The Time

Any sound engineer worth his salt should be striving to get better all the time. But how do we get better? How do we know if we're making progress or just making things louder? One really good way to get better is to get some feedback. By asking others to critique our mix, we will learn valuable insights and hopefully, get better. The challenge is, we're so trained to avoid feedback (the bad kind), that we tend to avoid all feedback (the good kind).

Now, it can be humbling to ask for feedback. I've done this in the past, and sometimes go home feeling less good about my skill level. However, after the sting wears off, and I've processed the feedback, my mixing usually gets better. It's easy to get caught in the trap of thinking we have this thing figured out and continue to do the wrong thing over and over again.

Read more: Feedback is not always bad.

   

Two keys to sound systems that behave well.

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Two keys to sound systems that behave well

When designing a sound system, physics still applies, no matter how hard I might wish that it wouldn't.  Many venues that we work in have low ceilings and comparatively far distances to the last row of the seating area.  Think of the typical 1970's Nazarene church -- long and low, and it could be built inexpensively with standard wood trusses and asphalt shingles.  60' from front to back, 10' side wall height, 14' roof peak. 

The Inverse Square Law says that sound pressure level (SPL) or acoustic volume drops 6 decibels (dB) every time you double the distance from the sound source.  If we measure 94dB at four meters from the speaker, the SPL will be 88dB at eight meters, 82dB at 16 meters, 76 dB at 32 meters, etc. 

When designing systems, if we're asked, what we hope to find is a room that's about twice as deep as the ceiling is high.  In that type of space we can keep the SPL difference to about 3-4dB over the seating area with conventional speakers.  Note that in the example above, there's a 12dB difference for the person sitting 13.2' from the speaker and the person sitting 52.8' away. That's why the 1970's Nazarene church style building is a tough place to install a sound system, and to do it well (not to mention inexpensively).  That difference is 12dB represents more than a 50% apparent reduction in acoustical volume.  

That halving of volume is not a big deal, if you want people to be able to sit in relative audio comfort at the back of the room, but more often than not, the audio technician (who typically sits in a corner in the very back of the room) adjusts the SPL to his taste making the acoustic volume much louder (read as "too loud") up nearer the platform or stage. 

Unfortunately, system performance is close to the last thing that many churches and other performance venues discuss prior to design and eventual construction.

Read more: Two keys to sound systems that behave well.

   

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