AVS Forum banner

Status
Not open for further replies.
1 - 20 of 20 Posts

·
Registered
Joined
·
56 Posts
Discussion Starter · #1 ·
I am about to have my basement remodeled and was planning on a RPTV HT system down there, assuming that front projection wouldn't work in the space, but I wanted to get some expert opinions here to make sure I'm correct. Here's the deal:


The ceiling will be a little under 7 feet high, and I have up to 14 feet of depth between screen and where projector could be mounted. However, there will be a boxed-in beam 8 feet from the screen, extending in height about 7 inches below the ceiling and about 6 inches deep. The screen could be up to about 7 feet wide.


My main concern is mounting the projector. I'm not sure if mounting it just on the screen side of the beam would give anough throw distance, particularly after the depth of the projector is taken into account. On the other hand, can it be mounted behind the beam without the beam blocking the image? The room is not a dedicated home theater, it will also be a children's play area, so I'm also concerned about having an expensive piece of equipment hanging in a vulnerable spot.


So, any ideas on how I could make this work in this space, or should I just go with my original RPTV plan? Oh, i also don't want to spend more than about $2k on a projector, but ambient light won't be a problem so I don't need a very bright one.
 

·
Registered
Joined
·
136 Posts
I have a very similar setup, so I have a little experience with this. Over the last two years I have been building a theater, and I pick up my Projector today, so I will let you know for sure BUT...


I would suggest a couple of things. Your beam is closer to your projection wall then mine, so you can do one of two things: 1) buy a very short throw projector, like a plus piano (check their throw chart at projector central) or possibly that new Sharp Theago (the Z90 with the very short throw). I saw the Theago at CEDIA, and they had it like 5 feet from the screen! Of course, your image may not be huge, but I haven't checked the specs. OR 2) Get a projector with lens shift or veritcal keystoning, hang it from the ceiling where you need to (say 12 feet back), and use the adjustments to center the image on the screen. The drawback to this strategy is you have to use keystoning (unless you have lens shift, and only a few 16:9 Pj's have that...notably the Z-1, PLV-60, PLV-70, Z9000 and Z1000) and keystoning puts the image through processing, so can effect quality a little bit. But you may not have to do too much keystoning if its far back enough. BTW, the HS10 has "side shot" which is a form of keystoning.


Anyway, I think your dimensions are doable. Everyone said my ceilings were too low, but I'm making it work. Ill post some pics soon. Good luck!
 

·
Registered
Joined
·
6,339 Posts
Hmm, mounting the pj onto the boxed in beam would be fine (I have my pj mounted to an enlarged bulkhead covering the beam although it is probably 5" higher than yours and it is 2 feet wide and 10' from the screen) but 8 feet is a little close for most projectors. For LCD, you're basically limited to the ae200 and sanyo z1 for their short throw. I am not familiar with short throw DLPs so maybe soemone else can offer some suggestions there.


At 8 feet with both the z1 and ae300, you could get a diagonal 16x9 image of about 80", give or take a couple inches. Also, you could use the lens shift (only on the z1) to make the image higher on the wall/screen if you found it too low.


putting the projector behind the beam could be done as long as you mount it perfectly so the beam doesn't get in the way. since the z1 (don't know about the other PJs) has the top of the image in the center of the lens, it shouldn't be a problem. You could do this right behind the beam...like 1 foot behind it. So at 9 feet, that'd give you an image around 90" diagonal, or, 80" wide.
 

·
Registered
Joined
·
56 Posts
Discussion Starter · #5 ·
Thanks for the advice so far (I LOVE these forums). I am also concerned about the projector hanging down from such a low ceiling, due to the risk of heads or kids' toys hitting it. How fragile are the low-end projectors people are recommending?
 

·
Registered
Joined
·
6,339 Posts
they're not too fragile but i don't recommend them taking abuse.:)


you could always build an enclosure for the projector. just make sure you have air circulation for it. I thinky ou could do this one of two ways:


1) cut holes where the fan & air vents are


2) totally close it all up and make it into a husbox by slapping external fans into the box.
 

·
Registered
Joined
·
245 Posts
The other option not explicitly discussed so far is to mount it on a shelf on the opposite wall (you said was 14' away?). You would likely place the projector upside down on the shelf or hang it from the underside with bolts.


The shelf height would be somewhere around 6' to 6'6 off the floor such that the center of the lens is an inch or so under the level of the underside of the boxed in beam. You'd be able to get a very large screen size this way and increase your options for projectors (and allow for future upgrades without limiting yourself).


This would place it out of kids reach and not cause a headroom issue in the middle of the room.


Go for the projector! It will be way better for you in a light controlled room than an RPTV and will take up essentially zero floor space as well (great WAF!). I used to have a 50" RPTV and was begining to think it was too small from my 10' viewing distance. Now I'm loving the 115" picture from my Sony HS-10 :) . Awesome!


Dave
 

·
Registered
Joined
·
56 Posts
Discussion Starter · #8 ·
I had thought about a shelf, but the wall opposite the screen has a window (small, so I'll be able to have blinds/drapes to cut out light), and the space right in front of the window is going to have a desk. Anyway, a couch will be between that wall and the screen wall, so I assume that the viewers would block the image if the projector were too far back in the room (DOWN IN FRONT!).


I should also have mentioned that the viewing distance will be about 9 feet. Is that enough to sufficiently reduce screen door effects?


One other question (god I'm annoying!) -- what is the fan noise like on the Z1 or the new InFocus X1? Odds are that the projector will be mounted very close to the couch.
 

·
Registered
Joined
·
6,339 Posts
with the z1, 9' won't be THAT bad if the sceen is like 80" diagonal and you adjsut the focus. With the ae300 I am sure it would be fine since it has the smoothscreen technology going on.


Have you seen many LCD projectors before? It is hard to tell how bad SD may or may not be for you.


Whatever the case, I think the AE300 might be your better choice bewteen it and the z1 for that close seating distance. Can't comment on dlp because i don't know what ones are short throw.


fan noise on both will are like 28dB whihc is pretty quiet for digital PJs.
 

·
Registered
Joined
·
56 Posts
Discussion Starter · #10 ·
Tell me if this makes sense, since I'm new to all this (although I've been reading up):


According to the throw distance chart for the Z1 on projectorcentral, with a 7' distance (which would allow me to mount it just on the screen side of the beam), I can get a screen width 51" to 62" (58 to 71" diag.). While I would lose the really big screen effect, I could then have a 55" wide screen (wtill a lot better than the 50" diag RPTV I was planning on) and, sitting 9' back (108"), get to a distance twice the screen width, minimizing screen door effect. Does having the projector close to the screen help control screen door, or does it make it worse?


I am also a little confused regarding mounting height. Can I mount the projector very close to the ceiling?


I have not been able to see an LCD setup, given the lack of showrooms in the DC area for front projection.
 

·
Registered
Joined
·
6,339 Posts
yeah having it close to the screen will make the screendoor less noticeable. if you did that as you say, you'd be fine.


the height of the image depends on the hieth og the center of the lens. Whatever is the height of the center of the elns will be the top of your projected image....this is with some projectors, not all. The AExxx line of pjs for exmaple, project the image higher than center.
 

·
Registered
Joined
·
157 Posts
Remember that many projectors project *below* their own level by a factor related to distance. In other words, a projector on the ceiling projects down, and one on the floor projects up, to put an image in the center of a wall. The top of your screen will be below the top of the ceiling, and by using the appropriate trigonometry you can figure out how far below the ceeiling the beam can protrude before it gets in the way of the light.


In fact, it seems to me that the *mount* would protrude about as far as the beam, which means there'd be no problem. Furthermore, for the pj for which I have tables in front of me (the NEC LT240, a short-throw pj) the top of an image 6 feet from a screen is 7.2 inches below the lens center. So it seems to me that placement behind the beam would work just fine.


Download a copy of some projector manual or other (avmall does seem to have the appropriate ones) and study the diagrams for projector placement.

http://www.avmall.com/files/x1_DS_E.pdf
http://www.avmall.com/files/x1_ug-english.pdf


If you're really worried about the kids, you might consider a short-throw projector in front of you, or use the keystone correction to place it to the side of the couch, and just put it away when you're not using it.


~ Kiran
 

·
Registered
Joined
·
1,237 Posts
or as others have suggested a box.. id consider having the pj in a box that and shelf araingment.. basicly when you power your equipment you can also have it trigger a sensor to drop the pj from the celing behind the beam.. just far enough to display correctly on the screen.. this would cost a little more but it would be totally clean install. i am sure you have a drop cealing. if this is the case running cables will be easy.. this will also increase the distance just enough to get you a few more inchs on your screen.. you can use x10 to run an electric motor to drop the pj.. or you can mount it with a lift strut and some sort of locking mech. when you push up on it the lock unlocks and it slowly drops down.. whne you are dun you push up on it and it locks up out of the way.. what are the deminsions to the beam??
 

·
Registered
Joined
·
56 Posts
Discussion Starter · #14 ·
Thanks, all, for your help. pen25, your proposal sounds really cool, but is way beyond my humble capabilities (or budget if I had to have someone do it for me). Also, I don't have a drop ceiling. (BTW, since you asked, the bottom of the beam is 77 1/2" from the ground, it begins 87" back from the screen, and it is 3 3/4" deep and will protrude 5" in height from the ceiling, which is 82 1/2".)


If the top of the image is at the center of the lens as rlindo says, then I can mount the projector behind the beam and still have between 6'2" and 6'3" of clearance under it, which would work for me (and would also result in the optimal screen size given constraints on that wall). Then, the image will be at a good height on the screen as well. Someone I spoke to at an on-line merchant told me that the Z1 projects down (when ceiling mounted) a bit; that would be a problem for me because the screen image would be too low. But, I assume I can use the lens shift to get the image at the same height as the lens center???


Also, what's the latest on the intermittent fan noise issue? I haven't seen a firm confirmation that this is a firmware version issue.
 

·
Registered
Joined
·
6,339 Posts
Hmm, I don't see how/why the z1 would projector downards from center when ceiling mounted. The z1 projects straight from the center when table mounted and I can't see it being different. Whatever the case, you're right and you can use the lens shift to shift the image upwards if it does in deed project downwards like that person told you.
 

·
Registered
Joined
·
1,237 Posts
unless you have people who are over 6'2 down there it really shouldnt be a problem. as far as what is beyond your capabilities to build is what you have to deturmin. it really wouldnt be that hard to build what i suggested.. just have to goto the hardware store and look at the different things.. I have seen people use all thread to ceiling mount.. you can use some brass tubing to cover the threads and make it look nice or use copper or use something like black heat shrink. paint all the nuts and washers black..if you do this use some nice MDF for the plate and use putty on the edges let dry and sand smooth so you can paint it what ever color you want and not have to worry about ugly edges..


as far as building a box that would allow you to drop it down you can get a couple of struts like they use for trunks at a local auto parts store.. mount 2 of them and get the lightest valved ones you can find. build your mounting plate the size of the pj youll prob need 2 of them one for top and bottom. the bottom will make a cover so when its pushed up it will be out of the way.. youll need 2 more peices either steel which you can pick up at home depot and use those as the passive links that will be the support. you will mount these on the top plate that will let the unit swing down and back and in place. the other 2 linkes(struts) will mount either forward or rear youll want to make the passive links the same length as the strut. possibly drawer runners will work for this so when you push it up they will slibe back and allow the unit to push forward and up.. i guess youll want the front link a tad longer and not want it to drop level since if it was a 90* it would lock into place and not want to go up.


again this is somethig you have to look at and see if you want to even try it. but thoght id throw it out since the hardest part is usually coming up with an idea of how to start..


you can also usually get push locks so when the unit is pushed up it will lock it up and push it up again and it releases it form the hardware store also..
 

·
Registered
Joined
·
1,237 Posts
oh ill try to do a drawing of what i am talking about a quick sketch if youd like.. and scan it.. it wouldnt be anyting special and it will be later on tonight since i have been up for 24 hours and need sleep.. pm me if youd like for me to put some sketchs up
 

·
Registered
Joined
·
157 Posts
Quote:
Originally posted by rlindo
Hmm, I don't see how/why the z1 would projector downards from center when ceiling mounted. The z1 projects straight from the center when table mounted and I can't see it being different.
The units I have investigated all project up slightly. If you look in the user's manual, there's a picture of this--in the case of the X1, the manual says,


"The image exits the projector at a given angle. The image offset is 112.2% when the projector is in 4:3 mode (default mode.) This means that if you have an image 10' high, the bottom of the image will be 1.22' above the center of the lens. This image offest is 124.7% when the projector is in 16:9 mode ..."


While I haven't investigated the Z1, specifically, I'd be surprised if something like this didn't also happen with the Z1.


~ Kiran
 

·
Registered
Joined
·
56 Posts
Discussion Starter · #19 ·
Thanks, Kiran. I know that's the case with many projectors. However, both the manual and rlindo say that, for the Z1, the top of the image can be level with the center of the lens. Anyone with any contrary information? This is an important issue for me!
 

·
Registered
Joined
·
157 Posts
Well, I'm surprised. In the ProjectorCentral review of the Z1

http://www.projectorcentral.com/sanyo_plv_z1.htm


they say "The optical geometry of the PLV-Z1 is set so that at the lens’ highest adjustment, the image is thrown with the centerline of the lens equal to the bottom edge of the projected image. The lens can be lower to the point where the centerline of the lens is equal to the top of the projected image. Therefore, for those who wish to position the projector at a height near the center of the screen (a rather atypical placement), the lens shift gives you great ability to adjust the position of the image. If however, you either coffee-table mount the projector at a height equal to the bottom of the screen, or ceiling mount it at the top edge of the screen, your only acceptable lens shift setting is in the extreme high position."


~ Kiran
 
1 - 20 of 20 Posts
Status
Not open for further replies.
Top