Quick Suggestion on HT Dimensions for a 120" Screen

[sam9s]

Hi All,

Thought to update that my Second phase of House Construction has started and the architech has finilized the ground floor and is in progress for the first floor.

First of all I would like to remind people who followed my HT designer thread that after sitting with my architech we came to the conclusion that HT in a basement was coming out to be VERY expensive, so keeping the floor plan same I have moved the project to the first floor. Now as I mentioned GF floor plan has been completed and 1st floor is in WIP, so before my architech can move ahead and seal the design he needs to know what exactly would be my HT dimentions and how am I visualising it so that he can complete the floor plan for the rest of the floor.
I need your suggestions here as to what shall I keep the room dimentions if I want to go far a 120" CIH screen. What I have thought is...

15' x 23' x 10' Room with rows starting at 15'. Projector will be Panasonic AE4000/3000. There would be 3 rows. The basic layout would look something like the below picture.

The rows would have a 1.5' step up. So the third row would be like 3' above the ground. Kindly suggest the ideal dimantiones, for 120" CIH and 90" CIH as well.

 

[sam9s]

Strange no suggestions.....I have to hit Google Uncle I think......

 

[sam9s]

mmmm no suggestions, is it that it looks like I am not serious or the query is tooo boring......anyway as I said I jumped in to the Google Ocean and got some good results. Made the final decission, thought to share the information/articles with you all, as it might help others as well.

To start with what i wanted was a way to calculate the approximate room dimensions given the screen size and the number of rows I would fit in. Basically something like a view distance calculator........ I got number of results for calculators to calculate the distance and the height and throw and blah blah but not exactly what I was looking for, plus most of them were to mathamatical and complex. Then I stumbled upon a very simple calculator and the right thing I needed. Its made by a person called Ken and called it Ken's Calculator for both 1.78:1 and 2.40:1 screen image. As I was interested in 2.40:1 CIH screen I followed that one. Following is the link for the same.....

Ken's easy to use screen calculator

It takes screen size, Lumens value and gain as input and gives the screen dimensions, area and viewing distance measured by different standards.......
What I was intereted was the screen Width and Maximum distance to fully resolve 1080p which was 16.5'. Other measures like THX and SMPTE (Society of Motion Picture and Television Engineers) were also suggested. SMPTE was 17.6'. So I think the safe bet was around 16' (thats where I would place the first row) .

Now the screen width was suggested to be 110.71" = 9.2' so if I have a room 15' wide I have like 15'-9.2'=5.8' left for both sides......divide it by 2 we get = 2.9' of space each side of the screen which is just sufficient I presume for speakers as well as keeping the esthatics. So room final width is decided to be 15'

Screen height from ground would be :::: 10' (room height) - 3.8' (screen or image height calculated by Ken's calculator) = 6.2' / 2 = 3.1'

Coming to the length of the room. For which I needed the throw distance of the projector(AE4000) and a recomemded distance gap within which the seating can be done. For this the following calculator came in to handy. Provided by our good old Projectcentral

Panasonic PT-AE4000U Projection Calculator - Throw Distance and Screen Size

You just need to put the diagonal screen size and the rest is calculated. For 4000AE at 2.40:1 ratio throw distance came out to be 16' 8" and at that through distance the recomemded seating comes to be between 13' to 20'
I have just three rows so if I place my first row at 16' (which is what I get from view distance calculator) and going by the de facto standard place the second row at 17.5' (spacing of 1.5'), the third row will be placed at 19' well between the recomended seating gap of 13-20' calculated by projection calculator.

Finally add 3' space behind the last row and I should get the room length of 19+3=22'

So finally the room dimentions that I will give to my architech for a 120" screen Home Theater would be 22'x15'.... Which is what my question was....



Now coming to my next query whic was the Raiser height, this is irrelevent at this moment but I found another handy calculator just to calculate this and so thought to share it with you all as well.

First, take the following measurements in the same increment (e.g. inches):

S=Floor to screen bottom
H1=Height of seated front row viewers top of head
E1=Height of seated rear row viewers eyes (no riser)
D1=Screen to front row viewers eyes
D2=Screen to back row viewers eyes

Then, plug them into these calculations:

H1-S=V1
V1/D1=R
R*D2=V2
V2+S=E2
E2-E1=Riser height

V1=Vertical 1, V2=Vertical 2, E2=Back row eye level (with riser).

For my measurements this is how it comes out to be....

Floor to bottom of screen = 32" (screen height from ground)
Height of seated front row viewers top of head = 42" (I took the default)
Height of rear row viewers eyes = 36" (I took the default)
Screen to front row viewers eyes = 16' (192") (calculated above)
Screen to back row viewers eyes = 17.5' (210") (16+1.5'(spacing))

Raiser Height come to be 6.4" ~ 7"

I am not sure of this is a concrete way to measure but seems ok to me. Also what I did was to put the formulas above into an excel sheet and prepared a simple script. All you need is to put the values in the cell and see the result. Uploading the xls sheet as well.

This concludes my swim in the oceans as I have my answers. Gave the dimensions to my architech as well and he is up and running to complete the first floor. As and when I have the floor plan will share it with you all.

Thanks and regards
Sammy

 

[srinisundar]

Good Sam, you could get the required dimension.. I believe for the last 2 to 3 days,,, forum is going in low side... Not much active... I am also busy touring i could not research in it..

Good luck for the next step.

 

[santhosh]

Nice to see progress on your HT front Sam. Wow, you are doing raiser seating - something that I always wanted to do. Will read your post in detail to understand as raiser and curved seating is a new concept to me.

Missed your thread, hence no reply.

 

[sam9s]

@Sri yea I can feel that too. not much of an activity recently, I hope when I start my house construction all are there to help and suggest

@Santhol2 thats ok. I got the information I wanted, but I hope the post is helpfull for other potential members looking in to a dedicated HT developement.....

 

[Raghav]

1. If you place your first row at 16', how will you place the second at 17.5'. A seat is minimum 24" deep and then if you leave 12" legroom, you can only start second row at 19'. the third row will start at 22'. I would start first row at 13', second at 16' and third at 19'. Seating end at 21' and then with 2' behind room length is 23'. This is in line with the calculator. Have I missed something?

2. How do you plan to place the screen in the middle of the wall, height wise. I thought that the screen starts close to the ceiling. Can a motorised screen be started 2' below the ceiling. I am asking as I have a 18" Beam near the screen which blocks the view towards the top of the room.

Projector decided is the same Panasonic AE4000 and room size is 17X11 and screen size most probably 7'x5'.

Screen height from ground would be :::: 10' (room height) - 3.8' (screen or image height calculated by Ken's calculator) = 6.2' / 2 = 3.1'
I have just three rows so if I place my first row at 16' (which is what I get from view distance calculator) and going by the de facto standard place the second row at 17.5' (spacing of 1.5'), the third row will be placed at 19' well between the recomended seating gap of 13-20' calculated by projection calculator.

Finally add 3' space behind the last row and I should get the room length of 19+3=22'

Thanks and regards
Sammy

 

[sam9s]

1. If you place your first row at 16', how will you place the second at 17.5'. A seat is minimum 24" deep and then if you leave 12" legroom, you can only start second row at 19'. the third row will start at 22'. I would start first row at 13', second at 16' and third at 19'. Seating end at 21' and then with 2' behind room length is 23'. This is in line with the calculator. Have I missed something?

When I say my row starts at 16', what I meant was the Recliner ends at 16', coz thats where your head is (your head should be at 16th' not your toe).... But Still this is a very very valid point brought, coz it seriously messes up my 2nd and 3rd row......

Even if i end my first recliner at 16' and start my second row at 17.5', my third row would start at 21' and NOT 19' THANKS for bringing this up.

So keeping the recliner depth at 2' my third row should end at 23' adding another 3' as originally mentioned the Room length now comes at 26' and NOT 22'......Good lord difference of 4' .... damm. THANKS again.

2. How do you plan to place the screen in the middle of the wall, height wise. I thought that the screen starts close to the ceiling. Can a motorised screen be started 2' below the ceiling. I am asking as I have a 18" Beam near the screen which blocks the view towards the top of the room.

I would not be using a motorized screen. What I am planning is a fixed 120" CIH (constant image height) screen to be able to play both 2.40:1 and 16x9 aspect movies using automated masking.

 

[Raghav]

A query: How to start motorised screen 18" below the celing? Is it possible?

If not, I will buy a 4:3 screen and sacrifice the top portion and use it in 16:9 ratio starting from the bottom of the screen.

I would not be using a motorized screen. What I am planning is a fixed 120' CIH (constant image height) screen to be able to play both 2.40:1 and 16x9 aspect movies using automated masking.

 

[cmsajith]

Nice to see progress on your HT front Sam. Wow, you are doing raiser seating - something that I always wanted to do. Will read your post in detail to understand as raiser and curved seating is a new concept to me.

Missed your thread, hence no reply.

I think you might be remembering, i suggested this setup for you or somebody else (its very long back, is it for sam himself?) in this forum with curved seating + risers along with curved screen. It will be a treat to watch in that kind of setup.

@Sam, It would be good if you add 2' to both sides (it will be helpful if you decide to go for a curved screen later) or doing 2 or 3 vertical false walls (another way to make an illusion of a curved screen on a flat screen) w/ indirect lighting (similar to cinema halls) which can be used to hide the masking cloth, motor etc)

 

[venkatcr]

A query: How to start motorised screen 18" below the celing? Is it possible? .

I am sure a carpenter can build a box that hangs from the ceiling or extends from the wall that can host the motorised screen.

Cheers

 

[Raghav]

That can be done but it will be an eye sore. After the beam there is approx. 3 feet distance to the screen. I would rather buy a 4X3 screen and watch it in 16:9 ratio. Then the eyesore is at least not there.

my 80 X 60 screen will become a decent 80 X 45 = 92" screen. I was hoping if we can have extra material at the top of the screen so that viewing starts 15" below the ceiling

I am sure a carpenter can build a box that hangs from the ceiling or extends from the wall that can host the motorised screen.

Cheers

 

[santhosh]

I think you might be remembering, i suggested this setup for you or somebody else (its very long back, is it for sam himself?) in this forum with curved seating + risers along with curved screen. It will be a treat to watch in that kind of setup.

@Sam, It would be good if you add 2' to both sides (it will be helpful if you decide to go for a curved screen later) or doing 2 or 3 vertical false walls (another way to make an illusion of a curved screen on a flat screen) w/ indirect lighting (similar to cinema halls) which can be used to hide the masking cloth, motor etc)

Yes cmsajith, I remember and would have loved to implemented it. Unfortunately, I do not have the room length to have raisers.

I am sure a carpenter can build a box that hangs from the ceiling or extends from the wall that can host the motorised screen.

Cheers

If this does not work, why not fix it directly on the rear wall? If you use a 4:3 screen, you will be distracted by the boxing that is caused by unutilised portion. Not sure about others, but for me that is a huge distraction. In my 120 inch screen, I have a 1 inch pillar boxing on both sides because of limited placing options in my Optoma HD20 and I am distracted heavily by that. My wife and dad are not even bothered about it. So it is just me

 

[sam9s]

I think you might be remembering, i suggested this setup for you or somebody else (its very long back, is it for sam himself?) in this forum with curved seating + risers along with curved screen. It will be a treat to watch in that kind of setup.

@Sam, It would be good if you add 2' to both sides (it will be helpful if you decide to go for a curved screen later) or doing 2 or 3 vertical false walls (another way to make an illusion of a curved screen on a flat screen) w/ indirect lighting (similar to cinema halls) which can be used to hide the masking cloth, motor etc)

mmm thats a good suggestion, I will consider that, however I would not be able to go for curved seating even if I want to simply because of the fact I have less number of seating, just 5. with a formation of 1 (front) 2 (middle) and a 3 set sofa at the third, so there is not much scope of curved seating...........yes curver screen is something I might look into.

 

[cmsajith]

That can be done but it will be an eye sore. After the beam there is approx. 3 feet distance to the screen. I would rather buy a 4X3 screen and watch it in 16:9 ratio. Then the eyesore is at least not there.

my 80 X 60 screen will become a decent 80 X 45 = 92" screen. I was hoping if we can have extra material at the top of the screen so that viewing starts 15" below the ceiling

Check the attached pic. Make a small structure from the front wall to the beam (covering the beam, should not feel like a beam existing once it is covered up) made out of ply and covered with veneer/cloth. Hang the screen using some strong chains till 18" so that the screen starts just above the slit (should be openable, incase of any repair) in the ceiling structure. Also project the structure a 2inch extra from the beam so that you can have lighting towards the ceiling. Motorized screen will be a nice addon, wire it properly to make it out of the sight.

To make the projection even on the screen, you need to bring down the projector. To make it more aesthetic, make a similar structure at the back side by covering the back side beam and fix the projector to the structure so that it will be like fixing the projector at the same height as the screen (literally it will nullify the beam existence) and you will not feel the projector is more towards the room as the ceiling ht at that portion is less. It can be made more interesting by fixing some spot lights to it (see pics)

In between the front and back structures, you can do acoustics with some indirect lighting to give an ambiance of an HT room.

 

[cmsajith]

mmm thats a good suggestion, I will consider that, however I would not be able to go for curved seating even if I want to simply because of the fact I have less number of seating, just 5. with a formation of 1 (front) 2 (middle) and a 3 set sofa at the third, so there is not much scope of curved seating...........yes curver screen is something I might look into.

You can use the curved seating with less number of seats also. Make the risers in a curved pattern and place the seats accordingly with enough space. The curved seating will give you an option for more leg room, since the seating position is not parallel to the seat in the front row.

 

[sam9s]

You can use the curved seating with less number of seats also. Make the risers in a curved pattern and place the seats accordingly with enough space. The curved seating will give you an option for more leg room, since the seating position is not parallel to the seat in the front row.

mmmm not bad....... not bad at all..... I will see how that looks esthatically, would sketchup and prepare a final drawing, that should give me an idea......thanks again...on to the drawing board....

 

[cmsajith]

mmmm not bad....... not bad at all..... I will see how that looks esthatically, would sketchup and prepare a final drawing, that should give me an idea......thanks again...on to the drawing board....

Ref: Like Gold class option in theaters (2 seater)

 

[sam9s]

Came back from my architect and told him to re consider the first floor plan with new dimentionas as 26x15. I will have a small break room and a PC gaming/Music room as well just along with the dedicated HT. Should have the final floor plan ready by a week. Will share it as soon as its ready.....

 

[santhosh]

@cmsajith: that is a fantastic drawing mate. Nice idea for Raghav, looks super neat. Only, Raghav has ensure sure it does not become a resonant cavity.

Came back from my architect and told him to re consider the first floor plan with new dimentionas as 26x15. I will have a small break room and a PC gaming/Music room as well just along with the dedicated HT. Should have the final floor plan ready by a week. Will share it as soon as its ready.....

Sam, will the PC gaming/Music room be a seperate room? Yup, share the plan when it is ready.