August 30, 2014
So let me talk a little more about my plans for the HT: I would like to have a four seat recliner around 13′ (4m) from the screen. The area behind the seats would be used to display my action figures, an office and a mini bar. Rather than covering the pole on the left of the seating with dry wall, I plan to extend the wall from the stairs all the way to the pole. This way the left and right walls of the home theater area are more or less the same.
I plan to design the theater in phases:
Phase one: I would like to get the basement done, get a desk and setup the office space, install a projector, a screen and 5.2 surround sound system. I will use my existing recliners for now, and look for deals on home theater recliners during thanksgiving.
Phase two: I would like to replace the recliners with leather home theater grade recliners. I would also like to install bass kickers on the new seating.
Phase three: I would either like to add two ceiling speakers to make a 5.2.2 atmos setup or add two rears and make a 7.2 setup.
So I need to keep the ideal end state in mind while designing the home theater. In this post I wanted to talk about the projector screen size.
Coming to the screen, I want to have the screen be electric and mounted on the ceiling. This way I can mount a TV on the wall, and have the screen drop down only while watching a movie or a game.
Given that the height of the room is 8ft (2.4m) and the length of the wall with the screen is 15ft (4.6m), I was thinking of using a 120in electric screen. The reason I am going in for an electric screen, is because I plan to mount a TV on the front wall and have the screen drop in front of it. The wife is totally against the idea, but I’ll keep trying to change her mind.
I am debating between the EliteScreens CineTension2, and the Visual Apex VAPEX9120TN. I’m leaning towards the Vapex screen as it’s slightly cheaper and it has a wireless trigger. This trigger will allow me to drop the screen automatically when my projector is switched on.
Coming to the screen size, I read that the THX recommendation is that the top of the screen should not be more that 15degrees above eye level. So I had to refresh my high school trigonometry. Back then, I knew of sin, cos and tan but never knew why they were used. Well, now I know.
Assuming that the height of the viewer’s eye from the ground when seated on the recliner is 3.5′, and the viewing angle to the top of the projector screen is 15degs. Let’s call the height of the projector above the viewer’s eye as x.
tan 15 = x/13′
x = 3.5′
In other words, if the viewer’s eye is 3.5′ off the ground the top of the projector has to be 3.5+3.5 = 7′ off the ground. Since I have a 8′ ceiling this shouldn’t be a problem – or is it? The Vapex screen is 74″ high (including the base) and the visible area is 59″ high. If I mount it on the ceiling such that the top of the visible area of the screen is 7′ off the ground, then the height of the bottom of the visible part of the screen off the ground would be:
7′- 59″ = 25″ off the ground
That would mean the bottom of the screen would be around 21″ off the ground as I expect there to be around 4″ of frame below the visible area. Since I have a 6″ stage, the height between the stage and the bottom of the projector would be 15″. The center channel should be around 8″ to 10″ so its going to be a right fit.
Coming to the width of the screen, the Vapex screen is 121″ which would give me a little over two feet on either side of the screen. A tower speaker should be around 12″ wide so I think I should be able to fit them in there. Not sure, if I will be able to squeeze in two subs though.
Widely sited research by the Japanese broadcasting company NHK found that 30 degrees is the minimum viewing angle needed to create an immersive “sensation of reality” in most viewers. i.e. If you are farther away it becomes less real. In my case, the viewing angle can be determined using trigonometry:
tan x = 52″/13′
x = 18.5 degrees.
So the viewing angle would be 2×18.5 = 37 degrees, which should be immersive without being headache inducing.
So when setup, it should look somewhat like this:
geekytalkies 