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Topic: AV Project for Elementary Gymnasium
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Joined: Mar 28, 2005
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I guess I didn't say it, but it is worth noting, that image size should be referenced by the screen diagonal in inches, not feet.

So, a 12' screen would typically be called a 144" diagonal image, and it should be either 16:9 or 16:10 aspect ratio.

So, a 144" diagonal 16:10 image is about 65 square feet in size. Under normal florescent lighting (classroom type) you need about 80 advertised lumens (minimum) per square foot for accetable results.

This actually works out to just under 6,000 lumens minimum brightness for that 144" diagonal.

The link you provided earlier, I looked through, and it is pretty good. It is all about a flat panel installation with protection and the like. You can buy LG 86" displays these days for well under $3,000. So, certainly putting up a big flat panel is an option, and having the school/kids/shop build a protective frame for it is a solid idea as well. What they did wasn't all that pretty, but it could be cleaned up with some paint and if the framing was a bit more even all around. I would also run all cabling inside of surface mounted raceway instead of having it just hang out in the open to be yanked on or hook on something.

Typical connection is HDMI from a good wall location to the room display. This can be done with HDBase-T extenders (HDBT) over cat-5e or better cabling. It's slim cabling from point to point and can be the exact length it needs to be.

Do NOT think that 4K matters. It does not. 1920x1200 resolution is all you should concern yourself with.

There are tons of wireless options for connecting a source. Most all of them are pretty bad to use. Most computers have a HDMI output, or can use a adapter to get from DisplayPort or Thunderbolt to HDMI. Liberty sells secure adapter rings which can be used if budget allows. I carry a Apple iPhone to HDMI adapter with me everywhere so I can hook my phone up to displays for testing. It works very well.
AV Integrated - Theater, whole house audio, and technology consultation during the build and installation process in the Washington, DC metropolitan area.
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Joined: Oct 8, 2019
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Thanks AV_Integrated.

Like I previously stated, my original idea was to get a flat screen tv mounted to a wall, add a pair of big bookshelf speakers and an apple tv and call it a day.

It's my principle that took the project and blew it up to a projector with full av system to create an area that could present multiple events outside of just my PE class.

Not sure where my project is going atm, just trying to work out the two options and see which is the best bang for buck option.
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There's no question that flat panels are providing a better deal with models like the 86" LG display for under $3,000 now.

But, projectors can easily deliver an image that is 4 times the size of that LG and have a very reasonable image in a lit room. The cost is going to be more, but the functionality and capability are much, much higher when in a larger venue and presenting to more people.

It must be said that while a wall can be painted 'white' and work with a projector, and is likely the best choice on a budget, the typical requirement is for a motorized tab-tensioned screen for best results, and those will run about $5,000 for a 160" diagonal size.

All this said, it is kind of a long term investment for the school and something that is becoming pretty common in new school construction to add a large projection environment somewhere in the school.

Some schools do just use a pull down screen and roll a projector in when they want to use it. That's certainly the budget option. It's also an option which can help keep all the components safer over the years.
AV Integrated - Theater, whole house audio, and technology consultation during the build and installation process in the Washington, DC metropolitan area.
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Thanks for your insight into this project AV_Integrated.

If I was to do a projector project in a gymnasium, what equipment would be required to make this work...

1. Projector
2. Screen
3. Speakers
4.
5.
6.
7.
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Typically you would sit down and do a drawing of the setup.

We've already talked about screen size and projector location and such, obviously that's critical.

But, you also need to figure out what you want to project! What sources do you want? Typical sources may include a laptop connection (HDMI) on the wall, a dedicated PC that is always on and connected and ready to project that's on the school's network. A cable box may be in there as well.

Then, with speakers do you want the ability to connect a microphone to those speakers? Wireless microphone or wired microphone? How MANY microphones?

How many speakers are proper for the space? Can you get by with 2 or 4 decent speakers on one side pointed towards a seating position? You don't want to overdo speaker or underdo them either. So, plan accordingly.

Typically, a mixer will be used to allow microphone connections. I use digital mixers from Biamp most often, but with basic microphone and audio mixing, there are a ton of options.

Biamp DSP:
Search eBay for Biamp Tesira Forte
Price: About $250 shipped
Make sure the unit has all the connectors on the back of it.
OR - It will need Phoenix connectors, which are easy enough to find, but may just need to call someone at Biamp to order a full set.


Then an amplifier to get audio to the speakers...
https://www.ebay.com/itm/Crown-CTS1200-Two-Channel-1200W-Power-Amplifier/401917390261?epid=14031748000&hash=item5d9424adb5:g:thsAAOSw0YxdnP7K

Add some speakers, which I go to JBL, QSC, or similar and typically would buy new.

Then you need something which can easily handle your HDMI sources and handle switching and audio breakout and perhaps volume control...

Search eBay for: Crestron DMPS3-4K-150-C
Price: $250 shipped
(has integrated hdmi extender you will need a receiver, also on eBay for under $100)

That product is a 6x1 HDMI/HDBT switcher with support for full 1920x1200 resolution and 4K/30 signals. It has manual controls on the front, but does require a bit of programming to get it to work perfectly. It should be paired with a touchpanel or keypad for best results. A simple 12 button keypad can turn sources on/off and make it all work with this system.

There are a few more components which are needed depending on where everything is located. I would put the A/V gear in a closet in a back room somewhere. Yes, it can be wall mounted on a professional Middle Atlantic rack (those are on eBay and Craigslist sometimes!). The Crestron switcher allows you to use cat-5e or cat-6 cabling to the projector location and to a HDMI input location. You will need a cat-5e receiver or transmitter at those locations to make things work.

These are all over eBay...
https://www.ebay.com/sch/i.html?_from=R40&_nkw=crestron+dm-rmc-scaler-c&_sacat=0&_sop=15

Super cheap with a original selling price of about $1000 each!
You will need a Crestron 2407 power supply to power them.
https://www.ebay.com/itm/OEM-CRESTRON-AC-DC-Adapter-PW-2407WU-GS-1753-RE-GT-41062-1824-24V-Power-Supply/233310348702?hash=item365261659e:g:BxAAAOSwk3NdTzjC

Also the wall connection HDMI input...
https://www.ebay.com/itm/Crestron-Wall-Plate-DigitalMedia-8G-PC-HDMI-Transmitter-200-DM-TX-200-C-2G-B/383173603395?epid=1151447066&hash=item5936ed3043:g:8N8AAOSwHGZdnIzS

This will give you a VGA with audio as well as a HDMI connection point for a laptop or ANY HDMI device.

All of this stuff came to under $1,000 to run the rest of the show and is ballistically good! Like, it's closer to $10,000 when it was new, but there's no reason to buy it 'new' as most of that stuff lasts for 15-20 years without a problem and is easy enough to replace for cheap if someone is willing to get their hands dirty.
[Edited by AV_Integrated on Oct 23, 2019 at 12:51 PM]
AV Integrated - Theater, whole house audio, and technology consultation during the build and installation process in the Washington, DC metropolitan area.
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