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139K views 2K replies 89 participants last post by  impreza276 
#1 · (Edited)
Hi. My name's Fred, and this is my first meeting. I haven't figured out what twelve steps go with the addiction I've developed, but I'm sure there will be wide screens and acoustically transparant everything.

Oh, wait. Is that not what we do here?


Seriously, getting this moving is one of those weird experiences where I'm not sure how it will turn out, but I've obsessed for long enough. I've told all my friends about how they'll never want to go pay for movie tickets again, and all they'll need to do it bring some popcorn and drinks. I just hope you all can help me bring that promise home, and within my lifetime.
I'm sure if you've read more than a couple build threads you'll recognize some design ideas I've borrowed (thanks guys!), but that doesn't mean I've thought of everything. So please keep an open mind and blurt out whatever you think - I know I'm trying to think creatively as much as possible, so I'm ready for suggestions.

I've purchased a recently built (in the last decade) home with a previously "finished" basement - we moved in October. I'll show you some pictures and video below, but all that will do is provide visual reference for the demolition that will need to happen. I'm not really sure how the previous owners used this space, but I can't imagine it was up to my standards for sound or light control. There are windows I'm afraid will have to go, and speakers in the ceiling that won't do at all, and hardwood flooring that I hope can be reused by someone else ...we'll see.

The prime space is around 12 feet wide (12 and a half in some places), 9 feet tall, and longer than I can use - 37 feet. There are one or two adjacent spaces that might become part of the whole experience - you'll see in the plans below.

Here's the bullets for a wish list
  • seating for 6 or more
  • superior sound control - a low noise floor especially.
  • light control - automated would be ideal, budget pending
  • constant height projection (no lens) and infinitely variable masking (automation not required)
  • acoustically transparent screen
  • concealed speakers as well as acoustic treatments
  • 7.2, maybe 7.4
  • equipment in another room (I have only a small number of pieces already - BDP, Boxee Box, a receiver I hope to use as amp)
  • the lowest budget possible*
I'll go ahead and post a layout and a video so you can see the space, and then I'll mention some of the challenges I've identified. (Pardon the video, embedded here, it seems to get stretched to 16:9, even though the iPod shoots video 4:3 - it's right on YouTube at my channel - HopefulFred)



Link to YouTube

The bad news:
  • The width is a fixed constraint. The sump pump and stairwell are not moving.
  • The existing soffits and ceiling are weird. Hopefully, when I tear down the drywall I'll find problems with solutions, and not just more problems.
  • The length will need to get worked out. The landing for the stairs may impose practical limits, but I'm hoping that I can make everything work well without getting too creative or having two doors in the theater (I'll show you what I mean in my proposed final layouts).
  • The HVAC unit that serves the basement is a heat pump, and the air handler is directly adjacent to the current finished room. I want to maximize the effectiveness of this unit while also keeping its noises out.
  • There are as many as four windows that may have to go entirely. Depending on final length of the room, I may not need to remove all of them. Or maybe I can be convinced I don't need to remove any of them, but I doubt that.
The good news:
  • The better half trusts me to handle this. She understands it will take a year or two ...or three (did I just jinx this already?) and won't try to stop me from building fabric wall panels or painting the ceiling black.
  • There are no kids; I feel like that's a plus just because it takes away one of the things people have to plan for. But given my other goals, I actually can't see how this makes a difference.
I'm sure there is other good news... like I have 9 feet worth of height to work with before riser, and I have access to some free materials that I may want, like four old theater seats (not the newer rocker style - the older flip seat bottom and solid arm design) and a section of old screen (not sure if it will be useful at all).

Here's my current working design plan. I haven't really considered an elevation yet, but once I get the length sorted I'll be looking into that to work out screen and riser heights.




Link to YouTube

Step 00 - Measure, plan, consult, replan.
Step 01 - Demolition
Step 02 - Reframe
Step 03 - Drywall
Step 04 - Risers and Soffits
Step 05 - Pre-Wire
Step 06 - Paint
Step 07 - Fabric Walls
Step 08 - Screen, Screen Wall, and Masking
Step 09 - Carpet
Step 10 - Seating
Step 12 - Calibration
 
Speaker Build (LCR) 

Thanks for reading. In the absence of better ideas, this is approximately where I'm headed. I'd love to have your thoughts and encouragement along the way.

Fred
 
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#52 ·
Well, good news. I talked with my dad, who works with engineering specifications of this sort for a living. If I understood him correctly, which I think I did, and if I've read a few wikipedia definitions correctly, which I think I have, I've determined that a 2x8 will be adequate for my ceiling joist span.


Mostly as a future reference to myself, but as general information for anyone considering their own span, here's a few good links.


First, the weight of drywall - according to the first good search result I found - is 2 pounds per square foot. http://wiki.answers.com/Q/How_much_d...alf_inch_weigh Even doubled, to 4 psf, that's a rather low dead load (remembering that my ceiling joists are like attic joists, with no floor laid on top).


Take that information and go to American Wood Council's online span calculator. Link Choose the species and grade I was instructed to (southern pine, No. 2), choose the member type (ceiling joist) and the spacing and sizing requirements of your application (in my case, 24 inch spacing, 2x8, and the smallest dead load option available) and the deflection limit you can tolerate, and the calculator gives you the maximum span. For my case, even assuming 10 psf dead load which is likely more than double my actual dead load, a span of more than 12 feet is manageable with a deflection limit of L/480.


What does that mean? Well, it means that even if I used four layers of 5/8 drywall, a 12 foot span supported by 2x8 southern pine wouldn't sag more than .3 inches. I can tolerate that!


I know I skipped the deflection limit calculation. Here is it. Deflection limit is given as a fraction (L/480, in my case). The span (L), 12 feet in my case, (I'm rounding a little) divided by 480 gives the total deflection. 12/480=0.025ft. 0.025ft x 12ft/in=0.3 inches or just under 5/16 inch. Ta Da!


I'll see if I can find someone to check my work here.


(Edit: my number for the weight of drywall was wrong for 5/8 gypsum. It's actually just over 2 psf - appox 2.2. That won't matter in the slightest, but it does make me more confident that I don't want to try 2x6.)
 
#53 ·
Having developed plans for the major obstacles - the window, the plumbing, the decoupled framing - I'm ready to start ironing out some finer design points. I've been trying to work with sketchup, and I'm no good at it. It takes me days and I still don't have a drawing that I can make mean much. Anyway, I took a page from someone else's book, and drew it on paper - as close to scale as I could without a ruler and graph paper. I think it came out pretty well.



In the hope that some of you are feeling creative, I'll post the blank that I photographed first. Please feel free to download it and draw all over it. Eventually I'll probably post several versions of it with different construction details on each version. In this drawing, the outer line is the limit of construction. For the top of the page (let's call it the north wall, because it's up - does that bother readers in the southern hemisphere?), that outer line is poured concrete foundation. The same is true of the eastern edge, and the eastern end of the southern edge. The western edge has been limited here by the second set of windows on the northern wall - the windows that will stay. Along the bottom of the image, poorly labeled, is the drain pipe from the rest of the house. It's near ceiling height, and will go inside the soffit. Near the midpoint of the south wall, there are a number of diagonal sections - this is where other drain pipes join with the main pipe, heading to the exit of the house in the east wall.




So, the first drawing I've made is for layout of the speakers, seats, riser, stage and soffits. I'll probably do some kind of proscenium as well, but it will most likely mirror the stage very closely (acoustics pending) Pardon the crudity. Notice I'm toying with the idea of armchairs for the first row. I like the idea of them being able to swivel around and be more social - but I'm not set on that. The second row sofa I drew has recliners on each end - I'm not sure I'll end up with that, but we saw one at a furniture store that was reasonably priced, so that's what I've been envisioning.


The speaker positions are flexible (as is the door), but I feel like these are pretty close. I'll hopefully be able to take lots of acoustic measurements and be confident in their locations before it's too late. I haven't decided on columns; they were in my initial plan, but I'm not sure any more. The screen here is about 9 feet wide. I hope that works out - I don't see why it won't. I've placed the front speakers a little narrow to keep them inside the 16:9 image. I've also hopefully left enough space for a set of masking panels for the sides of my 235 screen.


Also, the riser I've set here is two steps high - about 14 inches. I'll show you why in my next post.

 
#54 ·
Ah, nice! I can't use sketchup either. All my drawings/renders look like crap. Lost my patience with it long ago. I too resorted to the ole pen and paper "old school" camp for laying out my room. I went with graph paper though and did a "true scale" drawing of the room. LOL Looks good though, to me everything looks proportional in your layout.


I'm guessing the lighter grey line around the three walls is your soffit? It does look slightly larger in proportion, but that just might be do to your drawing skills or a requirement to make things symmetrical around the room and be able to get everything under wraps.


You just may want to add room dimensions to your blank sheet just to help us out a little.


Regards,


RTROSE
 
#55 ·
Yeah if you could add some room dimensions to your blank sheet then that would be a big help. I'll print one out tomorrow and draw up some ideas (time for bed now. Haha.)


I've got a few things in mind that might work nicely.
 
#56 ·
To get the room length I need, I've had to plan on relocating a door. The new position of the doorway at the landing of the stairs seems to interfere with the triple stud in that wall. As that wall runs down the center of the basement, and the triple stud is just about in the middle of it - I'm assuming it needs to be there.


Further, the entrance to the theater will need to be onto the riser. Since the step up to riser height is outside the theater, what I'm planing on doing is building a landing at the base of the stairs two steps high. This will move the new doorway to one side of the triple stud. I'll just continue the landing along the west wall of the theater, so that the stair landing is the same height as the riser.


The problem this makes is that the existing soffit for the drain pipe is too low for the doorway to be comfortable However, I can decrease the size of the soffit by a few inches if I remove the air duct from it, leaving only the plumbing. The new doorway will still be a little low - about 6'5" I think.


Luckily, since the air handler is under the stairs, raising the landing and extending it to the theater makes moving the ducting easy. It'll just run under the riser instead of in the soffit.


Here's the picture of the landing at the bottom of the stairs. The end of the theater will be almost exactly where the edge of the doorway is visible at the right in this image. The triple stud is just to the right of the double gang switch box. For reference to the floorplan I posted, we are looking "north," the stairs run east, and the theater is in the room to the north, but out of frame to the east. I'll repost the original floorplan of the whole basement again to help that make sense.




This plan doesn't show the new landing I'm talking about, but it does provide reference for overall layout.



So, whadaya think?
 
#57 ·
Sorry about the scale guys. I'll try to include something more descriptive in future iterations. However, if you look at the lower right of the image, I've noted that one line on the page is 10 inches. I think that the studs I drew, and the plumbing, are a little small, while the furniture and soffits are a little large. However, the stud spacing is pretty accurate.
 
#58 ·
I need help... Advice. For estimating materials, would you work from drawings? Does anyone have a good tool for estimating materials for stages, risers, soffits? The numbers are killing me.


So is the price. The nice man at Lowes explained to me some options for delivery of large orders and the way bulk pricing discounts work. Basically, if you need $2500 worth of stuff or more, submit one order and the guy at the contractor desk will whisk it off to someone at some corporate location, who'll mark it down for you. Then delivery is $79 per trip. Well as anyone who has done the math recently will know, it's very easy to spend that much money. I'm pretty sure I'll hit than number on lumber and drywall alone.


So I suppose I need to make as careful a plan as possible up front, to avoid extra delivery trips and minimize overage. Blarg.


How about some good news? I got a spare bit of house wrap from a construction site, via the architect, who happens to be the spouse of my wife's coworker. Why is that good news? Well, you need house wrap for when you remove a window and frame over the opening. House wrap is generally sold in huge rolls, for like $150. I only need about 25 square feet, so even the small roll (3' by 100' for $30) is overkill - not to mention I'd have a seem in the middle of it. On the other hand this bit of scrap that was destined for the landfill will suit my needs exactly, and for free.


The best part of this is that having secured some house wrap, I'm ready to remove the window this weekend. I'll be sure to take pictures so that all of you who wonder what it would look like to punch a giant hole in the side of your house will be able to live vicariously through me.
 
#59 ·
Well, I concluded I was going to have to work from precise drawings to be happy with my estimate for materials. I acknowledge that my order won't be exactly right, but I'll do what I can to make it as close as possible. My backside is just too water-tight, I guess. So I set about serious drawings tonight, and I haven't found the compromise I like. I need a recommendation from someone who has built one (a theater, a riser) before.


I started with this viewing distance calculator and Dennis Erskine's recommendation that the screen not exceed 80% of the room's width. Since I want a wide screen (2.40 is the number I'm using, but I plan on building custom a little large and masking down), I settled on 42 inches high. So that's about 101 inches wide (or 70% of my anticipated internal room width of 145 inches), for those keeping score at home. A screen almost 8 and a half feet wide is not especially large for cinemascope, I know, but neither is my room.


Next I putzed around in the viewing distance calculator and with my paper sketches until I decided (arbitrarily) that the first row should be slightly closer than the THX recommended 36 degree viewing angle. I settled on 40. That puts first row eyeballs 8.5 feet back (102 inches). That's right at 2.4 times the screen height.


Since riser height and position is the whole reason to do this, I went next to this vertical viewing angle guidleline to see how high I could mount the screen. Long story short, I used some trigonometry and an assumption about first row seated height and generated this diagram you see below. I limited the screen height to 15 degrees above the front row, to keep from getting a sore neck. Then I left about 6 feet (maybe 2 inches short) and found the second row height using the drawing tools.


This image is to scale! You might not like the scale, but it is. 1 inch is 2 pixels.
(At least it was before I uploaded it to photobucket, which reformatted my bitmap to jpeg - I'll attach the bitmap for anyone who wants it.) The whole white image is the entire space inside finished drywall (within an inch or two). I didn't draw in the floor or speakers or anything but the screen and heads. The difference in head heights is the riser height. I assumed 38 inches above floor for each eye. So, using the pixel counter features in MS Paint, I've determined that this scenario requires a 20 inch riser. I can't really build more than 14, so what do I push or pull?


Please help!


 
#63 ·
How high are you estimating the screen will be off of the floor? Have you tried the riser height calculator?


Also, do you already "KNOW" that you like to sit at 1.0 x Width back from the screen? This seems to vary from person to person, and will affect the riser height.


EDIT: Looks like the bottom of your screen is at 14" or so. That's pretty close to the floor. Did you intend to have a stage? having the screen that close to the floor will certainly cause problems with the riser height.
 
#64 ·
Well, see that's the thing. I don't really know what ratio is going to be best for me. I was hoping to get the first row a little on the close side, and the second row a little on the far side. That way neither would be egregious and I could pick the one I preferred later.


Do you have a link to the calculator? I've been doing it all long hand.
 
#65 ·
This next one is much better, but it pushes up against some other limits. This 48' tall screen is 9.6 feet wide (which will complicate my secret plans for masking), but with 11' first row distance maintains the THX viewing angle (36 degrees). The second row is now within three feet of the rear wall. I'm not sure how I feel about that, but at least the first row is not in the center of the room.
 
#66 ·
The process I've been using doesn't require I know the bottom screen position, but I went back and "measured" in the image. The most recent image has the screen bottom 29 inches off the floor. I haven't decided about a stage for sure, but I was planing on one, as well as a complementary proscenium over the screen.


Here's the process I've been using:

1. decide image height (arbitrary - guess and check)

2. use image height to get other screen dimensions and first row distance (THX 36 degree viewing angle for 16:9)

3. use first row distance and image height to determine top of screen (15 degrees up from first row eyes)

4. draw in screen, top to bottom.

5. draw in second row distance based on first row plus 70 inches

6. draw sight line form bottom of screen to second row

7. "measure" difference in eye heights to determine riser height
 
#67 ·
The riser height calculator is in the stickies. But here's the link


That link you posted earlier says the bottom should be no less than 2'-6" off the floor IIRC.


Also, barring actually having the PJ and doing tests, I've seen it recommended before to go to the movies and get a feel for where you like to sit. Count the ceiling tiles to get an idea of the width of the screen, and how far back you like to sit. Also consider how far up from the bottom of the screen you like to sit.
 
#68 ·
Thanks for the link. I'll bookmark it.


I see the minimum height you noticed. I'm close to that recommendation too; 29 inches is just over the 2'4" he gives here.


I think I'm zeroing in on it. I'll keep fiddling.


I have been trying to notice where I like to sit, and I think it is about 1 screen width for 1.85, so just inside two screen heights, which is pretty close, but not super close. I'll get back to work on some more complete renders and check it all out.


I appreciate the response - even you telling me what I would tell someone else is useful.
Sometimes I get a little lost in the details and need to talk it out.
 
#69 ·
Which aspect ratio are you planning for your screen? I thought you were laying this out for a 2.4, but I see you mentioned a 16x9 screen above.


Also, since we're talking out stuff you've already considered, how often do you plan to have people in the back row? Do you really want to give up that perfect seat ALL THE TIME, just so that EVERYONE (including you) can have an average experience when they do visit?


Don't get me wrong, your average is going to be 10x better than the best seats at the local theater, but still. It's something to consider...... again
 
#70 ·
My rationale for my seating preference is based on 16:9 because I believe that 'scope should be wider. If HDTV is large, but not too large (?), then 'scope is just wide enough to be awesome.



The issue with the compromise I mentioned earlier, in reference to one row being a little close and the other a little far, is my attempt at hedging, but also the result of real geometry problems. If "the sweet spot" for distance is a range only one screen high (say two to three screen heights), and rows can't be closer together than one screen height, then both rows can't be in the sweet spot. So, in my view, unless you can get a really big screen, someone is too close or too far. The question is only, which row do I want to sit in? And I'm happy to make that decision later. The decision I can't make later is how tall and how deep to make the riser.


I've proven to myself that if the first row comes back to eleven feet from the four-foot-high screen (13ish feet from the front wall), then the screen will be high enough off the floor for the riser to be sufficient at 14 inches. The only downside I'm sure of as a result of this is the proximity of the second row to the rear wall. Their are other possible problems, like screen width and my masking plan, plus I have to go find a projector I can afford to light it up (leaning toward the JVCs).


I totally dig where you're coming from about building a theater for empty seats; I just don't see that it's worth it if I can't share it. I'll tear my hair out for a little while trying to make the compromises that keep everything as good as possible, but hopefully when it's done I can let my guests have their choice of seat and know that I won't be disappointed - in part because I'll know I'd done everything I could to make it as good as possible. Of course, that's just my take on it. Has your planning been different?


I'll get back to my drawings...
 
#71 ·
Before I "settled" on a screen size I mounted my projector and tried different seating distances and screen sizes. I had originally thought that I would go with 114" inch screen and about 10 foot seating distance. I then went bigger with about 120" to 125" then decided it was too big. I finally settled at 115" and about nine feet seating distance. It took several hours of watching with different seating distances and screen sizes before I was happy/comfortable with my final decision. Just a little food for thought.


Regards,


RTROSE
 
#72 ·

Quote:
Originally Posted by RTROSE /forum/post/21820079


Just a little food for thought.

Appreciated. I'm hungry.


Hopefully I can build some wiggle room into the final positioning of seats so that no one is up against the edge of the riser and the seats can be moved after I get a few hours on the system.
 
#75 ·
Since we're brain storming, here's another question. Have you considered going with a larger screen and making the second row your prime spot? Most people would probably think you are giving them the best seats if you let them sit in the front. You're going to lose some space making sure your seats are far enough off the back wall, but this might give you some more options.
 
#76 ·
^^^^This might also be a solution for your thought on that the "prime" seating position is most likely in a bass null. More food for thought......since your hungry.


Regards,


RTROSE
 
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