# Check my numbers please?



## Bruce Fisher (Nov 24, 2007)

Hi all - I've been working on my HT rebuild for a few weeks now and I've been planning to do a CIH setup. My wife and I watch a 50/50 mix of HDTV and Movies.

I have changed my plans to an acoustically transparent screen (I think... SmX (gain of 1.16)) which allows me to use my space much better. I'm leaning towards a screen with a width of 120" and height of ~51" (gives me a diagonal of 130"). Planning on curved screen (I read that curved is better for anamorphic projection)

I'm considering using the Aussiemorphic MK3 anamorphic lens.

Using the Projector Central calculator (very handy assuming it's correct!), the BenQ W5000 isn't bright enough... but the Panasonic AE3000U is. Throw distance of 18'.

So what I'm wondering is...
- am I on the right track? Anything you'd recommend different?
- Can the Pana projector stretch properly for anamorphic lens? I did a search on that projector in this subforum and didn't find it which makes me nervous
- Could the BenQ handle a screen of that size? The next size down is 110x47"

Attached are two images with additional information. Assuming I go acoustically transparent, I will have to update the floorplan a little bringing the false wall into the room some.


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## Bruce Fisher (Nov 24, 2007)

after taping the screen to the wall... we're leaning towards the smaller screen size (110" x 47").


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## Prof. (Oct 20, 2006)

Bruce Fisher said:


> Can the Pana projector stretch properly for anamorphic lens? I did a search on that projector in this subforum and didn't find it which makes me nervous


I believe that projector is not suitable for AM projection..
If I remember correctly, that model uses preset aspect ratio's in an auto zooming operation..
-


> Could the BenQ handle a screen of that size?


It could but your fL is going to be below the recommended minimum.. 


> The next size down is 110x47"


That would be a better size..On zero zoom, max TR. you would have 20fL. at the screen, which is quite acceptable..



> Attached are two images with additional information. Assuming I go acoustically transparent, I will have to update the floorplan a little bringing the false wall into the room some.


I would allow at least 2'6" away from the front wall for an AT screen..


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## Prof. (Oct 20, 2006)

Bruce,

I've just had another look at your plan and you won't have enough room for an AT screen wall..
You only have 16" out from the front wall, to the side door..That won't be enough depth to place speakers behind the screen..
I believe there is a certain minimum distance needed between the face of the speakers and the screen material..something like 6" if memory serves..


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## Bruce Fisher (Nov 24, 2007)

Excellent feedback - very helpful.

I need to update the floorplan for different speakers behind the screen (if we go AT). Leaning towards Axiom W22 (on/in wall) or maybe the small Magnepans. Just in research phase - haven't had enough time to flush out all the problems with either of these approaches yet 

I plan to call SmX tomorrow to talk to them about their minimum requirements. I'll update here in case anyone else stumbles upon this later 

I have too many options - none of which are ideal due to my room!

As always - thanks Prof!


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## Bruce Fisher (Nov 24, 2007)

LOL - I should have just asked you to start with! 

OK, back to non-AT screen . How high is acceptable for installing the screen? I'm wondering - could I install a screen above the front speakers (instead of the speakers flanking the screen, have them below the screen).

I'm doing the math to ensure the speakers would never block the screen - but just wondering if it's "acceptable" to have the screen bottom about 40-48" high? (eye height on the couch is ~36-38") (bottom height would depend on the speakers I chose, but I am using about 38-40" tall worst case scenario)

On the wall, it looks fine to my wife and I... but I'm wondering if it will cause other problems I haven't thought about yet...

Thanks!


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## Prof. (Oct 20, 2006)

Bruce,

I would find 40" or higher off the floor a bit too high for my liking..
I think you'll find it very tiring after awhile, having to look up at the screen all the time..

I personally like to have my CIH screen down as low as practical, which I find very immersive particularly when you have a scene where the image is rushing towards you..Case in point..the scene from Star Wars 2 where Anakin is speeding across the desert, and you're sitting in his seat watching the scenery rushing towards you...The low screen puts you at his level and makes you really feel like you're there.!!

I have my screen 27" up from the floor...But then my speakers are mounted above the screen..

Having the screen off centre in the room does present a problem, particularly for the right speaker which would be very close to the RH side wall..
Placing the speakers under the screen would help with that, but then we have the screen height problem..unless you get shorter speakers..
Depending on your choice of speakers, you may be able to mount smaller good quality speakers above the screen..either in-walls or by having a shallow screen wall to hide them behind, as I've done...
Just a thought...


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## Bruce Fisher (Nov 24, 2007)

Thanks as always Prof!

I have been researching options and am leaning towards LCR type speakers... on their side... for all 3 fronts. (like Emotiva 6.3, Outlaw LCR, etc). Keeping them on their sides will allow me to lower them slightly (but not too much that they are too far below the listener).

I'm thinking I can find a compromise... maybe have the tweeter around 24-26" and screen bottom at 32-34" or something like that.

I know it's not perfect but I'm not sure I'll be able to find the perfect compromise! I spoke to Emotiva today about this scenario and they agreed - it's not perfect - but with the tweeter on top in the horizontal position - it's not a bad tradeoff. I'll be able to use great sounding speakers and keep my screen lower.

My only other option (I think) is to go with in-walls or thin on-walls (paradigm Millenium, etc) and AT screen.

Thanks!


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## Prof. (Oct 20, 2006)

I just checked out those Emotiva speakers and they certainly use an unusual configuration..They look more like centre speakers than floor-standers, so laying them on their sides might not be all that bad..
The only problem I see with doing that, is that you may not get a complete flow of sound across the screen...but then we are talking compromises here..
Placing them on low stands underneath the screen would still keep the screen height reasonably low, so that might be the way to go..

The in-wall type would allow you to go AT, if that's the way you would prefer to do it..

Good luck with it all and let us know which way you decide to go..


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## DucatiR (Oct 15, 2008)

Prof., 
A few questions along the vein introduced by Bruce. Thought I'd piggy-back here versus a new thread.

I was also considering the BenQ W5000 but haven't purchased yet. I am a little concerned after reading your comments below about the fL. My projector will be ceiling mounted about 15-16' from the screen. Screen will be maximum 100" width and also AT (Seymour's new XD material). The room will be totally dark except for rope light on the front of the riser. The projector calculator site (http://www.projectorcentral.com/BenQ-W5000-projection-calculator-pro.htm) indicates 14fL with those dimensions. Is that sufficient?

Also, I'd read in another thread or forum that the W5000 might not work for anamorphic projection. But according to at least one review the projector has vertical lens shift of 2 picture heights. I thought that would be enough?

Regarding sequence for anamorphic set-up, I may be approaching things backwards. I was planning to build my curved screen 1st but I've read that screen construction should match the anamorphic projection image. That means I'd need projector and lens first to measure the true pincushion. But that would mean a new projector would need a new screen and that doesn't make sense to me. Is there a correct approach or just a better approach?

Finally, in regards to AT material and speaker clearance, the Seymour website says:
"You can place the speakers up to approximately two inches from the screen surface, as long as you don't have ports with high velocity airflow." Chris at Seymour confirmed this in an email I sent him this week. Distance seems to be really speaker dependent - a subwoofer would need more space obviously.

Thanks in advance for any guidance. My carpet is being put in as I type so the screen wall vs. projector-lens sequencing is immediately in front of me.

Construction build thread:
http://www.hometheatershack.com/forums/home-theater-design-construction/13639-new-ht-project-construction-questions.html


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## Prof. (Oct 20, 2006)

DucatiR said:


> I was also considering the BenQ W5000 but haven't purchased yet. I am a little concerned after reading your comments below about the fL. My projector will be ceiling mounted about 15-16' from the screen. Screen will be maximum 100" width and also AT (Seymour's new XD material). The room will be totally dark except for rope light on the front of the riser. The projector calculator site (http://www.projectorcentral.com/BenQ-W5000-projection-calculator-pro.htm) indicates 14fL with those dimensions. Is that sufficient?


DucatiR,

Something doesn't add up here...
If your scope screen is going to be 100" wide, that gives a height of 42"..
When I put in that height for a 16:9 image (this is the aspect ratio you have to use) in the pro-calculator, it shows the mounting position at 13' 9" with an fL. of 25!! when using a screen with a gain of 1.0..



> Also, I'd read in another thread or forum that the W5000 might not work for anamorphic projection. But according to at least one review the projector has vertical lens shift of 2 picture heights. I thought that would be enough?


The W5000 works perfectly for anamorphic projection..



> Regarding sequence for anamorphic set-up, I may be approaching things backwards. I was planning to build my curved screen 1st but I've read that screen construction should match the anamorphic projection image. That means I'd need projector and lens first to measure the true pincushion. But that would mean a new projector would need a new screen and that doesn't make sense to me. Is there a correct approach or just a better approach?


The W5000 has a high TR., when set to zero zoom and from the projection distance and image size that you're looking at...
This means that you will have minimum pin cushion and that you won't need to have a curved screen..
I would just use a flat screen..



> Finally, in regards to AT material and speaker clearance, the Seymour website says:
> "You can place the speakers up to approximately two inches from the screen surface, as long as you don't have ports with high velocity airflow." Chris at Seymour confirmed this in an email I sent him this week. Distance seems to be really speaker dependent - a subwoofer would need more space obviously.


I agree that a front ported speaker would need to be further back from the screen than a sealed speaker..but my understanding is that it's not just the air movement from the ports that's the problem, it's also the radiated sound being reflected back off the screen material...
Evidently, moving the speakers a bit further back helps with this..


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## DucatiR (Oct 15, 2008)

Prof.,
Thank you for the prompt response! Good to hear about the W5000 and anamorphic. 

So I can still project 2:35:1, thru an anamorphic lens and simply adjust the W5000 onto a flat screen?!? :unbelievable: That would be great news - constructing a flat screen would be so much easier than a curved screen.

There is an additional radio button at the projector calculator for 2.35:1 or some other user defined ratio. That is what I selected and generated the values described in my post - is that incorrect? Sorry I didn't include that assumption. Mine were 2.35:1 aspect, 1.2 gain, 100" width (which actually works out 17fL.

As to the AT screen, from what I've read, there is sound reflection regardless of how far back you place the speakers. As you probably know, THX theater certification requires the speaker wall have baffling precisely for that reason. I intend to have something on the back wall to deal with that reflected sound. But I think maybe your point is that a sound source too close to the screen could have even more reflection than one placed further back? That could very well be the case. I am hoping to have more than 2" distance but it could end up being a compromise sacrifice to better screen/seating/projector distances.

Thanks again.


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## Prof. (Oct 20, 2006)

DucatiR said:


> There is an additional radio button at the projector calculator for 2.35:1 or some other user defined ratio. That is what I selected and generated the values described in my post - is that incorrect?


The 2.39 selection on the calculator is not for anamorphic lenses..
When calculating your values for anamorphic projection, you use the 16:9 setting since this is how you'll set up your projector for position etc..

This is the aspect ratio you use when setting up for anamorphic projection..The VS and horizontal stretch is done electronically and optically for 2.35:1 movies.. 
When the projector has been positioned correctly using the 16:9 image, then the lens is moved into position..

Now the other good news is, if your screen has a gain of 1.2, then you'll now have 29fL!

Bruce...How are things progressing with your set up?


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## Bruce Fisher (Nov 24, 2007)

this is great information prof - I too used the 2.35 selection not realizing I needed to use 16:9.

I'm planning to use the Seymour screen as well. Chris said he's working to get his frames in starting in June - so if he's not ready in time I'll be doing DIY. He concurred that I really don't need a curved screen - that was good news!

My update - I got my speakers in yesterday. I went with Emotiva 6.3s for LCR, XPA-5 amplifier (waiting on the ERD1 surrounds). They are beautiful in their own way (not a wood veneer, etc). They sound great - but they aren't broken in yet. I'm playing with putting them close to the wall and they sound great (sealed enclosures). Getting them close to the wall will give me more room behind the screen - I think I will have 3-5" which Chris thought would be fine.

Working on finishing wiring and projector/screen comes next. I see the Aussiemorph lens now comes in white - should look good with the BenQ 

< edit: I updated the first post images with my current plans. Nothing major >


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## Prof. (Oct 20, 2006)

The new plan looks good Bruce..

The only time you need to consider having the screen wall 2' or more out from the front wall is when you plan to have your sub/s behind there as well..
Should work well with the new configuration..:T


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## Mark Techer (Jan 17, 2008)

Just found this. The BenQ is a light cannon and will easily light a 150"(diagonal) screen. It has both Scaling modes and being DLP has a flat grey scale. I am LOVING mine


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## Bruce Fisher (Nov 24, 2007)

excellent - thanks for confirmation! So far i haven't found any negative reviews for that pj... i can't wait until I'm on that phase of the project


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