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Discussion Starter · #1 ·
Is it possible to mount a ceiling mount projection (Sharp DLP, etc.) behind, but just under, a 12" deep finished duct that runs across my HT room. The duct, which is 51" wide drops from a 7"8 ceiling. The problem is the duct starts about 9' from the proposed screen, which severely limits screen size if forced to mount the pj in front of it.


Can I mount the projector behind the duct so the lens clears the obstruction without cutting down my screen height? My fear is that I need to come down at least 12" just to clear the obstruction, then a few more inches to clear the lens, possible forcing me to project the screen image too low.
 

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The top of your projector lense needs to be no higher than the top of your intended image on the opposing wall. This means you can set it up so the bottom edge of your duct is the top edge of your screen (in general height terms). You're not going to want to put your image right against the ceiling anyway - so you're probably in decent shape. I have a 8' 4" ceiling - and the top of my image is about 19" below the ceiling - it looks good (initially, it seemed low, but it actually looks great). I have a Sharp DLP.
 

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Greetings,


I am a bit shaky on you explanation, but you seem to have 3 options.


1. By snugging the projector close to the clg. but under the fur down:

A, There will be a noticeable "projector path" on the fur down.

B, The screens top edge will not be any higher then the fur down.

C, But all the people will cheer.


2. By dropping the projector to gain screen height:

A, You may incur nasty bruise's about the top portion of your head and the heads of others.


3. By punching the projector into the back wall:

A, All issues may become solved

B, The throw distance may decrease image brightness if the room is 200' long.

C, But at 200' long, you will have no problem achieving the ultimate screen height.


Is the fur down portion of the rooms height 6'-8" with the highest area being 7'-8"? jdb
 

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Or, you could do what I did: move the duct.

Here's the pictures.


Not as expensive as I'd thought (actually, a wash in my overall construction budget - avoided some nasty sofiting.


And not only do I get clear slight lines and more headroom in the theater, but I'll have a nifty space for a marquee out in the lobby!


Randy
 

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Discussion Starter · #5 ·
Thanks for the responses...


jdb,


That is correct, the duct to floor is 6"8". So essentially this means that a projector hung behind the fur down will be sitting at 6'8" minus the actual pj height. I guess as you stated other option is to move priojector al the wasy back (~24') where it will not become a problem for viewers.


Am I correct however that many projectors need an offset for top of screen (or bottom if floor mounted) which is even lower than the straight line from lens. If so, this forces the screen even lower.
 

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I would assume that different projectors have differing offsets with respect to top of the image vs. top of lens heights. I have a Piano HE-3100, and the offset from the top of the lens to the top of the image is 18 inches at 12' from the screen (according to the manual - I've yet to install the pj). Check in the manual for your pj - it should have a table/chart that describes such measurements.
 

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Quote

"...Check in the manual for your pj...".


Ksoza - this sentence may become very important factor in determining just which projector to purchase.


One key (ha! half a pun) to the projector issue is to keep the unit on level with the screen. Then the Lens up or down from screen centre is adjustable with shift/ tilt with all but the least expensive units one could possibly locate for sell.


However, even this can be cheated to some degree with screen masking.


If burying the projector inside the the back wall is even remotely possible, then I would highly, strongly, most imploringly, suggest fleshing this idea out, and submit it to the forum members for their subjective review.


Data needed: side elevation dimensions, front speaker layout and seating plot.


What's in the room on the other side of the Theatres' back wall? Is there a room? By getting the PJ in there:


One, the hum, rattle, and heat of the projector becomes much much easier to deal with.


Two, the need for warnings and neck braces will be drastically reduced, depending upon room lighting conditions there after, that is.


And three, the "duct down" can stay, the screen top goes high, and completion date gets moved ahead 167 days.


The down side is you may have to be laying flat on the floor to watch a movie without your heads being in the path of the projector beam. Upside is you could save some hard cash by not having to buy seats.


Some people, like Cptn Randy, are just luck dogs. Are you in this elk? jdb
 
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