New home theatre room.

[Inertia]

My wife and I are planning a new home theatre room for our new house. I have some questions.... I heard that the room should be the height of the room multiplied by 1.6 and that gives you the width and the height of the room multiplied by 2.6 gives you the length of the room. That size room I heard was for excellent acoustics Is this correct? so i want the room 11'x 17.5'x 28.5'. I want a screen that is 9'x 16' that I am going to build with blackout cloth. My next question is what should the walls of this room be like? I don't want to spend a ton of money but would like the room to have excellent acoustics.

 

[Inertia]

Anyone have thoughts about this?

 

[abjonesiii]

9' x 16' screen? is that as in nine feet by sixteen feet?

If i'm reading that correct I'm sorry to tell you that that won't work very well with any projector under $50k. For a a screen that big you will need a throw distance of around 30 feet depending on pj model. Which will look horrible because most home theater projectors are not designed to throw that far. It will do it but the picture will be very very dull and disappointing. Most pj's need to be around 9-15 feet back from the screen to show a clear bright picture.

with your room size i would recommend a 110" diagonal screen (thats 55"x95") Thats doable by most pj's and leaves room on either side for speaker placement thats not directly against the wall.

I've heard numbers before on perfect room proportions but i don't know that they make that much difference with todays calibrating receivers and acoustical treatments.

Go to the bottom of the main forums page and click on member systems galleries and look through the pictures. They will give you a good sense of the room sizes and setups that others are using.

 

[AVRat]

Do you really want/need a room/screen that big? If so and you have the money, good on’ya. While the “Golden Ratio” may be targeted for good room acoustics, they are not totally necessary. You can use acoustic treatments to aid with the room’s acoustics.

The screen size seems exceptionally large for a room that size, but that is subjective. If you could elaborate more about the room’s layout features, it might make more sense.

If the room is 17.5’ wide with a 16’ wide screen, the screen would/should be acoustically transparent. Meaning you’d probably want/need a false screen wall. Also, with a screen that size, you’ll need a light cannon projector and a screen with decent gain to get the proper light output. AT screens have lower gains than non-AT screens.

Depending on where the front-most viewing position is located, the screen size may provide an uncomfortable vertical/horizontal viewing angle.

Nice little article: http://blog.audiovideointeriors.com/highend/1007listen/

 

[Phil Taylor]

What they said ... And I second (or third) the motion that 16' x 9' will take a honkin big PJ to effectively illuminate that huge screen. The Panny AE3000 will hit it full from about 25' but will be way dim unless you stack about three or four of them = $7500 | $10,000. Or use a screen surface coating of 4+ gain ... which wouldn't look too great...

 

[Inertia]

Right now i have a 120" screen. The projector I have right now is a mitsubishi and the picture is great! I thnk the projector I have says it can do a 240" screen.

 

[Phil Taylor]

Right now i have a 120" screen. The projector I have right now is a mitsubishi and the picture is great! I thnk the projector I have says it can do a 240" screen.

What model is your Mitsu PJ?

 

[Inertia]

Not sure on the model but its a DLP projector.

 

[abjonesiii]

Right now i have a 120" screen. The projector I have right now is a mitsubishi and the picture is great! I thnk the projector I have says it can do a 240" screen.

Like Phil said, "What model projector?"

My Optoma is rated for an image sie of 33.5" to 310" and I would never consider trying to get a pirture out of it at 310 inches that would satisfy my picky tatse.

As long as we are considering ratios the Golden Rule for seating distance is at minimum 1.5x the width of the screen, preferably 2x width. With a 16 foot screen you will need your seating to be at 24' back at 1.5x or at the preffered 2x you will need to be sitting back 32 feet, 4 feet longer than your room. That doesn't take into account another six feet or so behind the last row for surround sound placment. So we go up now to 38 feet not counting room for consession stand, popcorn machine, mini fridge, bar, etc.. If you can make the room that long go ahead and make it 6 feet wider and add a bowling lane.

Just my opinion. You can do anything you like its your theater after all. Enjoy it. Post up some pictures of the proscess. I love watching a home theater come together.

 

[Inertia]

We are not starting building our new house until next summer. Its the mitsubishi HC1500 I believe. Do you think it could handle a 160" screen?

 

[jostenmeat]

As long as we are considering ratios the Golden Rule for seating distance is at minimum 1.5x the width of the screen, preferably 2x width.

I don't know where you read about this golden rule, but I for one think its baloney.

The best advice is to throw the pic at the wall, and to use personal preference, especially when considering the ARs and native rez's that will be mostly used.

Did you know that many/most folks with anamorphic setups are only 1 screen width away?

We are not starting building our new house until next summer. Its the mitsubishi HC1500 I believe. Do you think it could handle a 160" screen?

I use a 159" with a JVC, and it looks ridonkulous. However, I've got a black floor in front of viewers, with dark burgundy sidewall curtains, and just as importantly I am using a retro-reflective high power screen with strategically placed projector.

 

[abjonesiii]

I don't know where you read about this golden rule, but I for one think its baloney.

Read this article:
http://www.projectorcentral.com/projection_screen_size.htm


now read this:
http://www.cinemasource.com/products/screens/about/about_screens.html


sure its subjective but what, you thought i was just making this all up?

 

[AVRat]

Short answer, yes, if you have a screen with decent gain like the Carada BW (1.4). However, the image brightness won’t be spectacular. Now with a Da-Lite HP (2.8) like Josten’s, you can see the image would be about twice as bright. The screen (gain) and projector need to be considered as a system.

Viewing distance/screen width (V/S) ratios are definitely subjective. A 1:1 ratio using an anamorphic setup (2.40:1) leads to about a 1.33:1 V/S ratio for a 16:9 AR setup.

Inertia, do you know what the V/S ratio for your current setup is? Is it about where you’d like to have it in the new house? If you base the viewing distance on the acoustic sweet spot of the new room (28.5 x 0.618 = ) 17.6” (211”) / V/S ratio = screen width. Doing this backwards with the 160” dia. (~140” width) 211”/140” = 1.5 or about a 36.5 degree horizontal viewing angle. Which is about the THX standard.

 

[jostenmeat]

sure its subjective but what, you thought i was just making this all up?

Thanks for the links. Now I recall that AH had an article saying that the author preferred 2x as well, but that preference is the key word.

2x screen width at least will get you some visual benefit of 1080p. Definitely not all of it though. And 2x screen width is 28 degree viewing angle, below both SMPTE and THX recommendations.

Short answer, yes, if you have a screen with decent gain like the Carada BW (1.4). However, the image brightness won’t be spectacular. Now with a Da-Lite HP (2.8) like Josten’s, you can see the image would be about twice as bright. The screen (gain) and projector need to be considered as a system.

Yeah, but just to clarify for the OP, the gain obtained is completely dependent on the on-axis/off-axis angle between PJ and viewer. The screen can actually go over 3x if the viewer is exactly in line with the PJ, but the point is that something like 2x is what is typically gained.

 

[Inertia]

AVRat you completely lost me there! Can you explain to me in laymans terms. Please excuse my ignorance I am basically a newb. Trying to learn as much as possible before we start the room.

My screen is 120" and the projector is roughly 16' from the screen.

 

[abjonesiii]

My screen is 120" and the projector is roughly 16' from the screen.

Great! That’s some numbers we can work with. So here we go:

You have a 120" screen that is 16' (192") in front of seating.

So ... 192 / 120 = 1.6 Your current viewing distance to screen width ratio is 1.6

Question is can you handle a 160"? Take 160 multiplied by 1.6 (you current setup) and we get 256 inches. Now lets get to feet.

256 / 12 (inches in a foot) = 21.33 feet

So, for seating YES. You could sit 21.33 feet back in your proposed 28.5-foot long room and watch a 160" screen.

Question now is that the ratio you like and will want in the future room? To answer this question take your current seating and move to within 10 feet of your 10 foot screen. That’s a perfect 1.0 viewing distance to screen width ration. Watch a few movies all the way through. How do you feel? If you feel fatigue, eyes water, neck hurts, you are too close. If you feel like that was great lets watch some more! Then you like the 1.0 ratio and can get a bigger screen. With the 1.0 ratio you could get the 16-foot screen, sit 16 feet back from it and be comfortable with plenty of room behind you.

*( not taking any lens action into account)

Next question is can your projector do it?
here's a great link:
http://www.projectorcentral.com/projection-calculator-pro.cfm

Plugging the numbers in on you HC1500 you could throw a picture 160" with a screen gain of 2x. That means none of that DIY blackout cloth stuff your going to have to shell out the bucks for the real deal. Going even further we can calculate that you could even get that 16-foot image you wanted out of the HC1500 with a screen gain of 2.8x. But the pj has to be 29 feet back pushing the boundary of your room (not counting any zoom) AND absolutely no ambient light in the room.

OK so here is the kicker. If you can then should you? This is another one of those subjective things we could debate but in my experience most hardcore video critics will argue that the high gain screens do not perfectly deliver the image. Not to mention the inherently small viewing angles <40 degrees. I know, I know everyone with high gain screens start throwing stones at me. I personally do not like the high gain screens. They don't look cinema like to me. With the exception of the very few high gain screens out there most screens with be 1.5 gain and below.

Its your theater. You are the only one it has to satisfy. So trial and error is really the only way to know what exactly looks good to you. If you screw up and do something or buy something you don't like its no problem. Just sell it on Ebay and get something different.

Lot of information huh? I know it’s confusing at first but the more you read and experiment the more it makes sense. I hope some of this helps.

 

[BMXTRIX]

Let's keep things a bit simpler...

Screen size is really subjective, and I see no issue with a 16' wide screen - if your budget allows for it.

On the low end, you want to draw about 12-15 lumens per square foot. The Mits HC1500, which you have can deliver about 1,600 lumens at brightest, but likely is in the 700 or less range when optimized for home theater.

Looking at the Projector Central calculator, and setting the image width to 192" (16') you end up with 5 lumens per square foot on that screen - less than half of the absolute MINIMUM that you should have.

http://www.projectorcentral.com/Mitsubishi-HC1500-projection-calculator-pro.htm

Since you are talking about blackout cloth - which works very well for smaller screens - you are saving a lot on budget, but adding absolutely nothing at all to screen gain. You simply are in the .9 to 1.1 gain range at most with blackout cloth.

I'm not against the idea at all and according to THX you should have your main seating about 1.5x the screen width - so main seating at 24' - which could work in the room.

Yet, for a screen of 144 square feet, you need a projector that can actually deliver a real world 2,100 lumens and is likely rated at closer to 3,000 lumens to hope to get that type of light output over the life of a lamp.

The projectors section has one such projector that was just listed... At around $36,000 it's a steal.

If we seach for 16:9 projectors under $15,000 which can deliver 3,000 or more lumens...
http://www.projectorcentral.com/projectors.cfm?mfg_id=any&res_id=any&ar=2&td=0&is=0&bll=3000&bul=any&cll=any&cul=any&wll=any&wul=any&prll=any&prul=15000&an=0&sp_id=0&dvi=-1&trig=1

We have seven projectors which can do it. Only one of them is 1080p, none of them are DLP, and only one of them is a 'value' projector - a Sony at $2170 street. But, that Sony, as great as the price is, does not have HDMI or any digital input and is 100% designed for business use.

Probably the best one on the list is the still business desinged Mitsubishi...
http://www.projectorcentral.com/Mitsubishi-FL6900U.htm

About $10,000 - and it can hit your screen and light it up like you should expect.

At the end of the day, I would bring the screen size down and recommend that to you. Move your seating closer, and treat the room with acoustics. Make the most of every aspect of the room you have, and keep some storage space in your basement. Unless you are prepared to dish out for the Sim2 CX3 for 36K, then don't ruin the space with sub-standard quality. Also, keep in mind that a room that size might also require a significant investment in new audio gear to actually get the sound to properly fill the space.

Budget accordingly and plan accordingly - but if the budget doesn't meet the plan, then adjust the plan to fit the budget... or raise the budget.

 

[AVRat]

I hope abjones post helped a bit, but I need to make a few corrections. He used diagonal measures not width measures but the calculations are the same.

We actually need your viewing distance to the screen, not projection distance. Is this the viewing distance that you’re most comfortable with? For calculations we can use the 16’ or 192”. Your 120” dia. screen is about 105” wide. So if you divide the viewing distance (192) by the screen width (105) we get a V/S ratio. 192 / 105 = 1.83

Ok switching gears for a second. Your first priority started with the acoustics of the room to come up with its measurements. You also need to take into account the listening position (LP) to account for room modes. Essentially you’re trying to minimize overlapping frequencies that create peaks and valleys (nulls) in the frequency response curve at the LP for a fairly flat curve. The most used position is at 38.2% or 61.8% of a room’s dimension from a boundary wall. So for your proposed room’s 28.5’ (342”) length, the sweet spot from the front wall is 342 x 0.382 = 131” or 342 x 0.618 = 211”. That’s about 11’ or 17.5’. You may notice that those two figures added together equal your room’s length. We’ll use the 17.5’ (211”) LP also as the viewing distance (VD) with the screen on the front wall initially.

Now that we have the VD and VS ratio we can figure the proposed screen width. VD / VS = SW (screen width). 211 / 1.83 = 115” So for a 16:9 screen the dimensions are 115” x 64.75”, or 132” diagonal.

Remember these numbers will change if your current viewing distance is different than the 16’.

I hope you were able to understand BMXTRIX’s post. According to the Projector Central calculator, assuming screen gain of 1.0 for the blackout cloth, your current setup yields about 18 lumens per square foot, which is decent. Now using the measurements from above, the Projector Central calculator tells us you’d need a screen gain of 1.3 to obtain the same image brightness.

Going back to your original 16’ x 9’ screen, the front wall measures 17.5’ x 11’, which leaves about one foot of wall space around the screen. Where do you put the speakers? What speakers will you be using? There isn’t enough room for proper acoustic placement. You should allow them to be placed at least 3’ from a wall boundary. The 115” wide screen fits well for this scenario.

If these numbers change so that the VD is shorter than the LP, then a false screen wall may be a good consideration. I’ve been planning a room not so different than yours with this situation.

Are you also putting in multiple rows of seating? Hope this helps.