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Church and H.O.W. Forums for HOW Sound and AV - Your Displayed Name Must Be Your Real Full Name To Post In The Church and HOW Forums => H.O.W. AV Archive => Topic started by: RevHitefieldjess on October 17, 2006, 12:54:52 am

Title: Equipment suggestions - AV system
Post by: RevHitefieldjess on October 17, 2006, 12:54:52 am
I am estimating a pkg for a youth camp that I am associated with.  This is, in large, part a labor of love.

I have a couple Q's about the sound pkg - those are on the sound thread.

They (camp) want to have a projector in the main room of the church (58' deep x 65' wide).  Used for Powerpoint, Media Shout, DVD movies and Broadband conferencing.  The signal will be sent to the main screen and needs to be routed to 4 aditional classroms.  These 4 classrooms will have projector systems and need to be able to receive the incoming signal and switch between that signal or an independent signal form a vcr or dvd or laptop.  The sound from the main signal (sanctary) can travel with the video signal.  I will also sent a sound only signal to the room.
There need to be provision of future growth. - I would like a switcher (if thats the correct term) to be able to handle the computer, dvd, vcr signals and a couple additional for possible future use.

Control will be with the sound booth.

Type of projector, wireing from projector back to source, switcher(?),
Sources will be - PC, DVD, VCR, ?
4 smaller projectors  - since they will be ceiling mounted -
what will be the interface allowing the pc or dvd to connect?
Title: Re: Equipment suggestions - AV system
Post by: Brad Weber on October 19, 2006, 10:55:37 pm
There are a lot of questions that would need to be answered in order to give valid responses that would fit your particular application.   What size screens?  What do you have for conduit?  How are the projectors to be mounted?  Who is installing all this?  What's the budget?  Future growth in the number of rooms, number of sources or what?  What is the ambient lighting in the rooms?  Who will be running the systems?  Where are the projector, control room and other rooms located relative to one another?  And many more.  Without that information most of what you get will be based on personal preferences and rather than on it fitting your requirements.

I understand that you are doing this in the spirit of helping, but it sounds as though you are asking somebody to design the system for you.  The best way to get a system design, equipment list and information on cable, hardware, etc. is through hiring a qualified consultant or design-build contractor, this is what they do for a living.
Title: Re: Equipment suggestions - AV system
Post by: Greg Hertfelder on October 25, 2006, 10:52:23 pm
Brad makes a number of good points regarding the complexity of a projection system, and the need to bring in some seasoned expertise. But, a good place to start is to start making a block diagram that will provide a road map for the signals. Draw signal flows left-to-right, with sources on the left and projectors on the right.

You will start with essentially two types of video signals, NTSC (National Television Standards Committee) interlacing video, and RGBHV progressive scanning video; the two don't mix. The NTSC sources (camera, DVD, or VCR), can be cabled in composite, Y/C (S-video), or component (think "good, better, best"). The RGBHV (red-green-blue, with horizontal & vertical sync) can terminate in the 25-pin high density connector, or in 5 seperate BNC connectors.

Seamless Switchers convert the NTSC to RGBHV, and then permit switching between RGBHV sources. Some manufacturers of seamless switchers are Extron, Kramer, Analog Way, and Folsom. If the computer and DVD player is next to the seamless switcher in the sound booth, the switcher will serve as an interface and switcher.

PC Interface
However, if the computer is located onstage, signal degradation can occur after the signal travels a long distance, so its advisable to employ a PC interface. The interface boosts signals, provides horizontal adjustment, and provides a buffered output if you need a local monitor.

Cabling between the output of the seamless switcher and the projector can either be 5-pair coaxial, or CAT-5e type (think computer network) cabling. The CAT-5 type requires a set of encode-decode electronics on either end that translate the RGBHV to the RJ-45 connector(s). There is a case for either kind of cabling, based on cabling length, ease of cable routing, conduit availability, etc.

Cue Monitor
When you design your system, make sure you have a cue monitor scheme for every source in the booth. For instance, you might want to cue up DVD program "behind the scenes: without needing to show the image on the projector at that moment, so a dedicated monitor or TV would be appropriate. And likewise, it's nice to know what the computer is outputting before you unblank the projector, so a monitor that displays the output of the computer makes sense.

Extron is considered by many to be the industry information source. I recommend that you spend a lot of time on the web site looking around at the different devices, glossary, articles, etc.