Organizing the A/V equipment needed for Chapel Presentations

[roblad]

It usually takes an hour of somewhat anxious activity to get ready for a presentation in the chapel that involves, video, cordless mikes, and occasionally an emergency audio backup for receiving stake conference broadcasts. Occasionally it is desirable to connect to a TV on the stand that leaders can watch. Sometimes it is necessary to have the ability to switch between several A/V input devices.

The A/V inputs can include a laptop, a smartphone, an iPad, Miracast, Apple TV, DVD player, and etc. Sometimes you don’t know until the meeting starts what type of media you have to work with.

To be successful, you usually have to collect a number of things together including cables and adapters. It is not uncommon that something has gone missing and the setup usually looks like a mess.

I have been wanting to find a way to clean this up so the setup would be easier and so the capabilities would be the same for every meeting. I've shared three photos of the setup.

Here is a description. Three objects were attached to the front of a piece of 3/4" plywood that was painted white.

1) A Behringer XENYX 802 mixer Audio Mixer, Sometimes this is needed to get enough volume from an input device.

2) A Blackbird 4k 4x2 HDMI Matrix
Provides selecting between 4 possible A/V inputs and two outputs.
It provides an audio only output.
The 2nd HDMI output can help with putting a display on the stand.

3) Behringer Ultra-DI DI400P This is a replacement for "the crab" except that is a lot tidier

None of these are expensive.

Several cables of various configurations were needed to make all of the permanent connections.

I think the key contribution of this came from something that may seem pretty silly. It was to permanently attach a 9" by 13" Tupperware sandwich box under the piece of plywood. Holes were drilled through it. All of the wire, cables, and wall warts, and the power strip were put in the box. The lid is easy to remove but the intention is that it is left closed and never touched.

The only wire that leaves the board when it is not in use is the power cord that goes to the plug strip that is hidden below and inside the Tupperware container.

All of the connections were straight forward with one exception. If the audio from an HDMI signal is stereo, there was a need to turn it into a mono feed for the chapel sound system. The trick for doing this is to connect all four of the RCA jacks for Tape In and Tape Out together. The 1k Ohm output impedance makes this work. Doing this makes turns the Control room output into a Mono signal. The Main Output remains a Stereo signal.


Completed A/V Interface board

IMG_7536.JPG

View from the bottom showing what is inside of the Tupperware box.

IMG_7537.JPG

View of the entire assembly from the bottom.
All of the wiring is inside and the lid does not need to be removed.

IMG_7538.JPG

[aclawson]

Looks good, but I'd be a tad worried about heat buildup in that tupperware box, even with holes cut.

You can get a 2" x 2" DC fan for about $10 online - I'd add one of those to keep air circulating through the box.

[roblad]

Nothing inside of the box generates heat except for a couple of wall warts that don't get very warm. The main purpose of the box it to contain all of the wires to keep things neat. Most of what is inside is just wire. There are no holes in the box except in the bottom so the wires can pass through.

[kreeve]

Thank you for sharing your design. I like how you are doing it.

I too am finding the need to put monitors on the stand as more and more leaders including visiting authorities are using visuals, video/audio in their presentations.
I bought a 2 input 4 output HDMI switcher that I put in the podium cubby, and feed the projector and the two monitors from. I use a external IR extender to be able to switch this from a distance.

The standard issue EPSON projector has a 1/8 inch mini stereo output. When most laptops detect devices on the other end of the HDMI cable, they will route the audio out the HDMI port which ends up at the projector. I feed that 1/8" audio to a Rolls AV PResenter. The standard issue crab does not have sufficient audio output levels to work with todays laptops and tablets.

http://www.rolls.com/product.php?pid=DB14
So I run a XLRS mic cable from this to the wall jack. This device has 1.8 stereo and RCA in jacks, and a XLR mic level jack out with two volume controls on it.


I have two challenges I am working on.

#1 Doing an AV mute on the projector from a distance when their is not a presenter so the blue screen of NO AV signal is not showing/distracting.
#2 The monitors I use on the stand are 2012 LDS issue Toshiba TV with built in DVD players that have VGA, HDMI and Components in on them. They shut off after some period of no detectable signal, and I found out today that they will not sync to the higher resolution PC laptops when powerpoint goes into presenter/full screen mode. So they show an unusable input message. The projector handles these just fine, as does the 4k HDMI switcher/distribution amp.

I have a plan from #1, and looking for downconverter or another monitor idea for #2.


Kevin
YSA Stake, Logan UT

[roblad]

I found that by navigating the menu of the church's flat panel TVs that you can change a setting that will keep it from timing out.

To avoid having unwanted light on a monitor or screen, I try to put everything including all videos in a PPT file and then make sure that there are blank slides between slides that are not to be sequenced thru. I also use the magic "B" key (on the windows keyboard) to get PowerPoint to blank the image on screen. By doing this you can keep the screen clear of anything that should not be seen.

[roblad]

I'l like to see a new crab device be provided that has an HDMI input in it and which will strip off the audio. This would have to be an active device.

In addition to this, for receiving a multi building broadcast, there needs to be two channels and two adjustment knobs on the device. One is for the emergency audio backup that comes form a cell phone and the other is for the audio that is extracted out of the HDMI connection to the webcasting laptop. It isn't good to expect the operator to switch wires when a fail-over is needed. Two knobs should be provided so both audio inputs can be active together. The device I built does this. It should be possible to have a new crab developed that does it all and then have it be standardized across the church.

[roblad]

The standard issue crab does not have sufficient audio output levels to work with today's laptops and tablets.
Kevin
YSA Stake, Logan UT

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We found that there are thee different generations of the LDS crab. The current one in the black soft cover case does have enough gain to work well with laptops and smart phones. If you have one of the old ones changing a couple resistors and wiring the transformer in series will fix it.
Roger Oblad - Santa Rosa CA stake

[kreeve]

Good info to know on the new generation of Crab boxes. If you could share the new resistor values (I have not opened one up) etc I would tackle it. I am very comfortable at soldering.

[russellhltn]

The big problem with the older crab boxes is they were designed to also connect to the phone line. That really drags things down. The newer ones in the black case doesn't have that feature.

[aclawson]

I don't know where it came from but an Emtech EJ-2 Plus has appeared in the office: a passive device with nothing but L/R RCA jacks in, XLR out, a volume knob and a switch to disconnect the internal ground.