Building new Home Theater in Basement - Page 2 - Home Theater Forum and Systems - HomeTheaterShack.com

Old 08-13-13, 09:35 PM Thread Starter
Shackster

Join Date: Aug 2013
Posts: 9
Re: Building new Home Theater in Basement

Quote:
sdurani wrote: View Post
What viewing angle are you comfortable with? 45 degrees? 55 degrees?

Once you decide how big an image you want to see, then it is easy to figure out the seating distance from the 144-inch screen that will give you that image size.

Once you have the seating distance for the main row, then you need to decide how much space you want between your main row and second row.

Once you know where your rows and screen are, then it's a matter of putting a box around it for the room.

But first you have to decide how big an image you want to see (viewing angle).
Hi Sanjay,

I'm assuming that you are referring to which angle I"m comfortable with when I watch movies in theaters.

If this is the case, then I must say that I enjoy watching movies in the last few seats.

I don't know how this can be translated into a viewing angle.
MoonLaf is offline

Old 08-13-13, 09:39 PM Thread Starter
Shackster

Join Date: Aug 2013
Posts: 9
Re: Building new Home Theater in Basement

Quote:
Prof. wrote: View Post
If you're using a 2.35:1 CIH screen (and I assume you are since you mention using an anamorphic lens or memory zoom) then the minimum distance seated from the screen is 1.5 -2.5 x the height of the screen..(depending on the quality of the screen material and your preferred seating distance..
So if the height is 56"..multiply that by 2.5 gives you 140"..11'6"
At 19' you would not get that visual impact from a very large screen..

Distance between first and second row is generally about 6'..depending on the type of seats that you'll be using..

Here is a calculator for determinig those distances..

Hi Prof,

I did my research again and found the following equation:

Minimum Distance = 2 x Screen Width (2 x 132.6 = 265.2" = 22.1 ft)

Maximum Distance = 5 x Screen Width (5 x 132.6 = 663" = 55.25 ft)

According to the following site (SMPTE recommendation):

http://www.theaterseatstore.com/How-to-Measure

But again, when I checked the following site:

The minimum and maximum distance according to SMPTE & THX are totally different.

So I tried to use the theater calculator in this site:

http://carltonbale.com/home-theater/...er-calculator/

Again, the calculations are different !!

When I read about others experiences in building their own home theaters, I thought that I'm lucky since I'm still building my own house and I can control the dimensions of my intended home theater.

But now I'm feeling the opposite, it seems that they are the lucky ones.

They already have existing rooms and they will do whatever to adjust to what they have; hence the limited options they have.

Couldn't there be a simpler way for me to determine the dimensions of my intended home theater room & the distance of the first row and second row of seats based on Screen Size?
MoonLaf is offline
Old 08-13-13, 09:51 PM Thread Starter
Shackster

Join Date: Aug 2013
Posts: 9
Re: Building new Home Theater in Basement

Quote:
cmohan wrote: View Post
Hi Mouna,
I am in the process of finishing my basement with home theater and I am going through similar questions.

Here is something for you to consider (hope I am not adding to the confusion). For your screen size (132x56), you are getting a 2.35:1 aspect. But in this screen, if you project a 16:9 image, filling up the entire height, your real image will be about 100x56 giving a diagonal size of 114. This may surprise you by giving a small image. Try putting up a a blanket or something folded to 2.35:1 and 16:9 aspect ratios and get a feel for if it is small or not.

I have a 11ft wide wall which will have my screen. I am going with a 120" wide screen. For 2.35 aspect ratio, my image height will be 51". Corresponding 16:9 width for 51" height is ~90". When I put the blanket up it appeared way too small, also giving me vertical bars of 15" on each side.

My solution was to go with a hybrid approach (referred to as Constant Area). I just increased my screen height to 60", making it 120"x60". Now for 2.35 picture I will be using 120"x51", leaving about 4.5" horizontal bar on top and bottom. For 16:9, I will be getting a 107"x60" (6" vertical bar on each side). If you want to get fancy, you can get masking for them.

This brings in an additional demand on my projector - lens memory . Why? When I want to watch 2.35, I need to project the 16:9 (with horizontal bars) onto a size 90"x51". Which will be stretched vertically by my projector (to fill the black bars) and stretched horizontally by the A lens (x1.33) to 120. (my choice is JVC D-ILAX35. Other similarly priced option is PT-AE8000 - there may be others. My friend's Epson 6020 did not have lens memory, only manual zoom).

If you survived reading this far, since you have 132" wide screen and you chose to go with constant area approach, your results will be as follows

2.35:1, your image size will be 132"x56" (area : 7,392 sq.in)
16:9 your image will be 118"x66" (area : 7,788 sq.in)

From the areas you can see they are not same (as constant would imply), but very comparable. On the other hand your 132x56 screen would have given your 16:9 image an area of 5,600 sq.in. Huge difference.

Unfortunately I am still building the theater, doing calculations and starting to order equipment. So I can't tell you how it worked out yet :-)

Hope it turns out the way that will make you the happiest.
Hi cmohan,

I know exactly what you are talking about

This surprises me as well, but thanks to the following articles:

The Most Important Decision to Make For Your Home Theater, Size

The Most Important Decision to Make For Your Home Theater, Width

Choosing Screen Size, Part 1

Choosing the Right Screen Size, Part 2

Choosing the Right Aspect Ratio

Choosing the Right Aspect Ratio Part Two: The Cinemascope 2.4 Option

Choosing the Right Aspect Ratio Part Three: The Problem with Cinemascope 2.4

But I guess I don't have to worry about those things now. I have plenty of time to think about it.

My main concern now is to determine the dimensions of my home theater room to start designing the house and the begin construction afterward.
MoonLaf is offline
Old 08-14-13, 12:18 PM
Senior Shackster

Join Date: Oct 2010
Location: Monterey Park, CA
Posts: 489
Re: Building new Home Theater in Basement

Quote:
MoonLaf wrote: View Post
I enjoy watching movies in the last few seats.

I don't know how this can be translated into a viewing angle.
Every little bit of info helps. In this case, your viewing choice means erring on the side of a slightly smaller image rather than too big (fatiguing).

Our human vision has an optimal viewing angle of around 15 degrees vertically. SMPTE says "for most viewers physical discomfort begins when this angle exceeds 35 degrees". Considering where you sit in a movie theatre, I would keep the vertical viewing angle of your image in the low 20-degree range.

The 2.35:1 screen you've chosen is 56 inches tall, which means sitting 12 feet from the screen will give you a 22 degree vertical viewing angle while the 132-inch width means a 49 degree horizontal viewing angle; immersive without being uncomfortable.

I would put the second row about 5 feet behind the first row. Where these rows fall in a room will depend on whether the sound is as important to you as the picture. You haven't mentioned sound at all, only video equipment, so I don't know if audio is a priority for you.

BTW, how big is your current television set?

Sanjay
sdurani is offline
Old 08-14-13, 01:49 PM
Senior Shackster

Join Date: Dec 2012
Location: Al A Bama
Posts: 327
Re: Building new Home Theater in Basement

Not to add another variable to your decision but since your planning....

Determine your type and budget of seating as best you can now. Seating can run from \$300 per person to \$3000 per person. Arguably if you go mid to high end it will be a significant part of your budget.

If you plan on having a reclining row in the back be sure to plan for that space. If the chairs will recline back like a lazy boy 5 feet from back to back of rows is fine but you will need 2 ft reclining behind the back row. If you get incliners (typical HT seats that can hug a wall or bar top behind) you will need 6.5 ft from back to back of rows. Otherwise a larger persons feet will be at the back of someones head.

If just couches then no worries.
bamabum is offline
Old 08-14-13, 06:13 PM Thread Starter
Shackster

Join Date: Aug 2013
Posts: 9
Re: Building new Home Theater in Basement

Quote:
sdurani wrote: View Post
Every little bit of info helps. In this case, your viewing choice means erring on the side of a slightly smaller image rather than too big (fatiguing).

Our human vision has an optimal viewing angle of around 15 degrees vertically. SMPTE says "for most viewers physical discomfort begins when this angle exceeds 35 degrees". Considering where you sit in a movie theatre, I would keep the vertical viewing angle of your image in the low 20-degree range.

The 2.35:1 screen you've chosen is 56 inches tall, which means sitting 12 feet from the screen will give you a 22 degree vertical viewing angle while the 132-inch width means a 49 degree horizontal viewing angle; immersive without being uncomfortable.

I would put the second row about 5 feet behind the first row. Where these rows fall in a room will depend on whether the sound is as important to you as the picture. You haven't mentioned sound at all, only video equipment, so I don't know if audio is a priority for you.

BTW, how big is your current television set?
Thanks for the informative reply Sanjay.

I think I'm getting your point. The below article helped me to visualize it.

Vertical Viewing Angle

The sound is important to me of course, but I thought that I would keep it for a later stage since I'm only deciding for the dimensions of the room now.

I didn't research this point yet, but I'll go for 7.1 System.

Any particular thing I need to decide now regarding the sound that will effect the dimensions of the room as well?

My current TV set is Samsung LED TV 46"
MoonLaf is offline
Old 08-14-13, 06:27 PM Thread Starter
Shackster

Join Date: Aug 2013
Posts: 9
Re: Building new Home Theater in Basement

Quote:
bamabum wrote: View Post
Not to add another variable to your decision but since your planning....

Determine your type and budget of seating as best you can now. Seating can run from \$300 per person to \$3000 per person. Arguably if you go mid to high end it will be a significant part of your budget.

If you plan on having a reclining row in the back be sure to plan for that space. If the chairs will recline back like a lazy boy 5 feet from back to back of rows is fine but you will need 2 ft reclining behind the back row. If you get incliners (typical HT seats that can hug a wall or bar top behind) you will need 6.5 ft from back to back of rows. Otherwise a larger persons feet will be at the back of someones head.

If just couches then no worries.
That is an excellent point bamabum.

Actually, I was planning to leave a space behind the back row.

In one corner, I'll place a mini bar and in the other corner I might place a standing Split Unit AC.

Here is an example of what I'm thinking.

By the way, I was thinking of getting Arc shaped seats for better viewing to my guests, what do you think?
MoonLaf is offline
Old 08-14-13, 07:57 PM
Senior Shackster

Join Date: Oct 2010
Location: Monterey Park, CA
Posts: 489
Re: Building new Home Theater in Basement

Quote:
MoonLaf wrote: View Post
The below article helped me to visualize it.

Exactly. The diagram shows a screen height that stays within the optimal cone of vision for us humans (15 degrees), though it can be exceeded slightly (22 degrees) in order to get a more immersive/involving image.
Quote:
MoonLaf wrote: View Post
My current TV set is Samsung LED TV 46"
Play a movie with a 2.35:1 aspect ratio and put your eyes 44 inches away from your TV. This will give you a rough idea of how big the image will look if you sit 12 feet away from your proposed screen.
Quote:
MoonLaf wrote: View Post
Any particular thing I need to decide now regarding the sound that will effect the dimensions of the room as well?
When sound bounces around a room, it creates loud peaks & quiet nulls in the frequency response at various locations. These variations between loud & soft are smallest at odd divisions (thirds, fifths) of room length.

With that in mind, I would make your room 25 feet long. This will allow you to place the rows at 15 feet and 20 feet from the front wall (3/5ths and 4/5ths of room length, respectively), leaving 5 feet between rows. Using seating placement to smoothen the frequency response means less relying on absorbtion and equalization to do those same things.

The screen can be on a false wall 3 feet from the actual front wall, which will put the screen 12 feet from the front row (to get the angles mentioned earlier). The false wall will also allow you to hide speakers/subs and room treatment behind acoustically transparent cloth, for a clean look.

Sanjay
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Old 08-14-13, 08:27 PM
Senior Shackster

Join Date: Dec 2012
Location: Al A Bama
Posts: 327
Re: Building new Home Theater in Basement

Mooney,

I like your rendering. Rendering really helped a lot in my planning. It allowed me to trust the design during a build which is important.

Sanjay has some great advice!

The things I am most glad I did were:
1- Create false wall. treating the wall in front was the best thing for acoustics I did. In a box room there is such a slap echo that you can not listen to anything very loud. It literally hurts the brain. After treating the front wall I could increase the DB level safely and enjoy much clearer sound.
2- The false wall with acoustic screen lets you put the center at eye/ear level. Once you know this and understand it is hard to watch with the sound from a ground stand. The is amplified in the back row where the front row eats up the sound from the ground placed center.
3- Give enough room between the rows. I have friends in the 6 ft range that can recline without hitting those in front as well as 4'5" friends that can still see over the front row.

In your drawing there are a few things that stand out.
1) It looks VERY nice!
2) The concave angle on the back riser is the wrong direction. There are plenty of posts why you don't want the U to be that direction. Switch it. Take a look at "The Cinemar Home Theater Construction Thread". Ask him a question or two about this. He will respond as he is great. Note a curved angle is either a nightmare or \$\$ for the carpet guy (especially with pattern carpet) or more work for you the woodworker. If this is acceptable proceed forward as it make a dramatic statement.
3) Look at seating from Pallisar or others to understand curved seating now. I fear your bar area will not have clearance for stools as well as recline from far right seat. Also, a reclined seat in far left back will block the exit. A curved seating arrangement requires more space in the riser, especially if the front row is strait.
4) Determine your riser height with your drawings. A standard step is 7.5 in. plan for that and a riser around 12-14 in according to my understanding of your setup. Calculations will tell you.
5) can you post a view from above with measurements, this will give you more feedback.
6) I have 12 and 19.5 head to screen distances and it is about perfect for two rows. I used 16:9 so if you use cinema you can get away with a little bigger screen.
7) Simulate! If you can afford the projector now, set it up in your garage and project onto a wall. it will tell you so much. blue tape off the floor like the room. I found my seating ahead of time. I then simulated in a room with a chair and pillow to get the same height. With an avg sized guy friend I sat behind them and gauged the height I would sit with my risers and projected screen. This told me more than any of the calculators.

Enough rambling. Enjoy
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