After looking at different screen options I stumbled across this forum and the various posts describing building spandex acoustically transparent screens. It has definitely been interesting reading the historical progression of screens over the last five to six years.
My plan is to build a 120” wide by 68” tall (~138” diagonal screen) frame and using the milliskin matte silver and milliskin matte white spandex. My projector is a Viewsonic Pro8200 that I found a couple months ago on a daily sale at Amazon.
My current theater area is in a windowless section of my basement that currently (unfinished) measures 12.5 feet wide by 16’ feet long. I plan to finish this room out using techniques that I’ve read in the Dedicated Theater forum, but before I settled on screen size and seating orientation I wanted to do an “alpha”/trial theater to see how we use the theater as a family and what we prefer from a seating distance, etc. I currently have the projector up and projecting on a white painted concrete wall. The seating is currently at a 1:1 screen width distance and I think we could probably go in between .8 to 1.2 and still enjoy a 120” screen.
I also think I’m currently on the constant image width train of thought given that I enjoy playing video games as much as I do watching movies, and I prefer the largest 16:9 screen when I play games. With that in mind I was also mindful of using horizontal masking panels when watching movies so I tried to keep that in mind in the design. Using a basic excel calculator I calculated that a 120” 2.35/2.4 screen is roughly 50” vertically. Assuming that the image is centered vertically then I would need top and bottom masking panels of 9” or so when watching movies.
On to the screen:
The frame design that I settled with is similar to what
did with his screen. The outside border of the frame is 2x4 pine that sits on the narrow edge assembled. I decided on this type of border to allow me a bit more lumber to work with if I want to add borders later on, and I also was thinking that the top border would work as a shelf for my xbox Kinect sensor.
I’ve been going back and forth on how to incorporate the Kinect in the theater because my family loves playing Kinect enabled games. Since a 120” screen will fill up most of the screenwall the top is the only place that I think I can put the sensors, and I’ve been thinking of having the actual consoles below the screen potentially behind a panel that I can put up and take down as I need to access.
I bought two 10’ boards that actually measured a little over at 120.5” and I bought two 84” studs to cut down for the verticals. I planned the height to be 67.5” with the verticals on the inside of the 120” horizontal 2x4s, which meant I needed to cut them down to 64.5”. Actually cutting the lumber was quick work with my miter saw.
I decided to add mid supports on the 3rds to support any potential mid span bowing. I compared 1” lumber between the poplar, oak, and pine, and settled on poplar based on some recommendations in this forum, price, and perceived weight as I held them in my hand in the lumber aisle at Lowe’s.
For all joints I used a Kreg R3 jig to drill pocket holes and used 1.5” coarse pocket screws. This was my first time using the Kreg jig and I am impressed with how it works and the ability to hide the fasteners in the joints as part of the technique. With that said I am not a fan of the square head fastener. Overall, I prefer a star head bit versus the square head. For the frame because the Kreg kit comes with a long driver bit due to the angle of the screw, I really had to focus on making sure the bit and screw head were firmly in contact and keep firm pressure while screwing to make sure I didn’t strip the head of the screw. This probably would be my only preferred change in the kreg kit and pocket hole screws, but it’s definitely a minor issue in comparison to the rest of the flexibility the Kreg kit offers.
I also had some Neodymium ½” by ¼” magnets from a previous homebrew stir plate project that I decided to embed in the border of the frame. After I assembled the frame I then used a Forstner ½” bit to drill a little over ¼” into the wood to add the magnets. I only had ten magnets, so I tried to distribute the magnets to where I thought they might have the best coverage later for either a frame or maybe masking panels for when I switch to 2.35 format material. On the verticals I drilled holes 4” from the corners, and on the horizontals I added a magnet 16” from each corner and also mid-span (60”). As strong as these magnets are, I’m guessing that they will be strong enough to support a horizontal masking panel. Fingers crossed. I also wanted to add the magnets before I painted the screen so that the silver coating on the magnets would be the same color as the rest of the frame.
Now the next part I wasn’t sure about as I didn’t see anything definitive in the previous builds that I went through. I decided to paint my screen frame black to prevent any potential ghosting on the image from light reflecting back through the spandex. On some builds it looks like some folks didn’t paint at all and didn’t notice any negative effects, but on others they mention painting, and specifically looking at granroth’s build he used a gray tinted primer.
Unfortunately I was so caught up in the excitement of assembly and the urge for progress that I forgot to take pictures of the frame before painting. Hopefully above I’ve provided enough description though to understand how I built the frame. Here is a picture of the frame as I prepare to attach the first layer of spandex. The front of the screen is facing up with the back on the bottom. The vertical supports will be offset from the spandex by the width of the 2x4.
I decided to go with the popular milliskin flat white over milliskin flat silver from Spandex World. I ordered 3.5 yards of each to ensure I had enough to stretch across the screen and also to hedge against getting the spandex shipped folded in a box. The good news is that the spandex came rolled and well packaged! I’m pretty sure I spent the same amount of time building the frame as it took me to open the plastic around the Spandex roll. And just like damn Aunt Betty at Christmas who double wraps the presents, sure enough Spandex World subscribes to the same principles! Once I broke through the first blue barrier, I immediately found a protective clear under layer with clear tape that I carefully disassembled to make sure I didn’t damage the fabric.
I was grateful to see that the silver spandex was on the outside of the roll, because I was able to just unroll that portion and repackage the white until I was ready to staple it to the frame.
I used the technique described in this picture, which basically has you rotating sides and stapling twice in each long horizontal side and once in the vertical sides. As MM so nicely points out in granroth’s thread, there definitely is something to this that can only be gained through upholstery training or repeated exercise of applying spandex.
Here are the tools that I used to staple the spandex to the frame: ¼” T50 staples with my EasyShot Plus staple gun. I decided on the ¼” staples as I figured that it shouldn’t take much holding power to keep the spandex taut and also if I needed to remove staples these should come out fairly easy.
And here is a couple progressions:
NOTE: I in fact did not order my spandex medium rare, but rather limited by my image capturing technology
Halfway through stapling:
Almost to the corners:
Now at this point I ran into an issue because no matter which way I stretched the fabric across the frame I had wavy wrinkles in either direction. I’m not sure what caused this, but I think it may be that I didn’t put enough tension on the short sides as I stapled around the frame. For the height of the screen I think it is easy to know when you get enough tension because you can feel the stretch and the tactile feedback helps you know how far to pull and staple. However, across the frame since I had plenty of fabric to work with it was hard to tell when to staple because it didn’t feel the same. I pulled to the tension that I thought was the same as the vertical sides, but in retrospect I’m not sure I did it correctly.
Before posting this I went back and re-read granroth’s experience and I understand now how he felt when he got to the corner. I basically went into the same steps without realizing it. What I ended up doing is pulling the corner tight and then basically working back towards the middle of each side and pulling down a bit and stapling until I had the front of the screen smooth. Unfortunately, what that caused was horrible bunching on the sides that I now understand were the “warts” in granroth’s title. I’m not sure how bad it would have been to leave these, but I couldn’t. They looked horrible and I was worried that it would get in the way of the top layer staples, so what I did was go back along the edge and re-staple to create a “good” line of staples that I knew would keep the tension correct. That allowed me to take out all of the previous staples on just the short sides and clean up the loose fabric. I’m not sure how susceptible spandex is to fraying or running, but trimming the edges had me a bit nervous that too close would allow a run that could ruin the screen, so I left about a half inch from the staples hoping that would be enough. The image below is of the “better-side” before I refinished the staples. It was frustrating to have to redo the sides, but ultimately not that much effort or time compared to having a quality edge and peace of mind.
Here’s a picture before correcting the “warting”:
After pulling staples and straightening the side fabric and trimming around the back:
Here’s a picture of the full screen with the silver layer fully stretched. In order to capture the full size of the screen in all its glory I did have to climb to the tippy top of my ladder. Like Tom Cruise, I do perform all of my own stunts. (MI5: Rogue Nation reference for all future readers)
After doing corrective maintenance on the end pieces it was time to put the matte white over the top of the silver.
Here is the beginning of the stapling process starting. To try and help make sure I had the spandex aligned with the frame I marked the midpoints of each side of the frame with a sharpie, and then folded the spandex on each side and marked the midpoint of the fabric. I did not do this for the silver and finding the middle of the long edges wasn’t too bad, but with all of the bunched fabric on the short ends I thought maybe I didn’t get it centered well enough and that was what caused my corner issues with the silver.
Beginning the stapling with the matte white:
Midway through stapling the matte white over the silver.
As I worked my way to the corners, I was working to avoid the same issue I had with the silver of uneven stretching across the verticals and the horizontals of the frame, but I ended up in the same place. Instead of repeating the mad stapling exercise that I went through for the silver I continued working to the corners as best I could and when I was near the corner on the long horizontal sides I went back and removed the some of the staples on the short vertical edges all the way back to the midpoint and then stretched the full fabric towards the corner and used clamps to hold the fabric as I added tension and removed the wavy wrinkles from the fabric. I ended up having to do this for both sides, but it went faster the second time. Work efficiencies and all that.
At this point I think it was good to follow the pattern for stapling to get even stretching to the corners, but I think if I had more clamps I would only clamp the short ends so that I could adjust as I needed as I went too. I’m also wondering if I had ordered only 3 yards or maybe trimmed the spandex to the same amount of difference on all edges then would that have helped me stretch and feel the right tension across the whole frame. I.e. For the top to bottom stretch I had 8 inches in difference in the frame and fabric, so maybe if I’d trimmed the 10.5 feet of fabric down to 9.25 feet maybe it would have worked better.
Here’s a picture after I straightened the side and before I put the final staples in.
Also another issue I ran into with my EasyShot stapler was that the internal spring tension of the stapler was not enough to staple through two layers of spandex easily. I found the only way that it wouldn’t shoot staples back at me was to channel my internal Daniel Larusso and breathe through each staple along with a mini-punch/push against the frame. Come to think of it maybe a headband would have helped too.
With the Screen frame done I mounted two of these French cleats at the top centered on the vertical support bars in the back. These specific Hangman brand French cleats came from Home Depot. (Hangman 200 lb. French Cleat => http://www.homedepot.com/p/OOK-Hangm...5316/202341629
I also ended up using 1 5/8” deck screws to attach the cleat to the frame and I put a screw in each of the larger holes in the cleat. I wasn’t a fan of the small screws provided, so I improvised with fasteners I had on hand.
Hanging the screen:
I used a seating eye height of roughly 40” to estimate where I wanted to hang the screen vertically on the wall. At 67.5 inches, I calculated that I wanted at most a third (67.5”/3 = 22.5”) of the screen at 40”, which means that at most I could hang the screen 17.5” off of the floor. That would put the top of the screen at 85”. After marking this off on the wall I had a couple reservations about hanging it that high: 1) When sitting the image seemed to be a bit too high for my liking; and 2) I have an HVAC supply pipe that consumes 12” of vertical space against the wall where I wanted to hang the screen. Taking that into consideration I decided to lower the screen to be 80” from top to bottom of the floor which would clear the HVAC and also lower the screen to a more comfortable viewing angle. The new position actually centered the screen between the floor and the floor joists above, and I have 12” above and below the screen.
I also debated painting the support for the screen black to avoid reflections or distractions while using the screen. In my brief testing after hanging I did not notice the supports reflecting through the screen, but to be fair, I have plenty of other places in the theater that would cause visual distraction before the supports I think would be noticed.
Screen hanging on the wall:
Screen with default xbox one dashboard with lights on:
Screen with default xbox one dashboard with lights off (and by off I mean the manual unscrew the bulb method, since my entire basement lighting is on one circuit):
Thoughts & Cost:
It’s still new, but the difference between the Kilz white paint versus the spandex is amazing. I’m highly impressed by this relatively cheap method of creating a screen. I think it will be a great tool for my family and I to decide a final viewing size and seating distance for when I’m ready to finish the room. I am definitely leaning toward a false wall with about 18” behind the screen to add my LCRs and subwoofers, but I want to also experiment with what that will do to the screen size as well. I cannot move the projector back any further as it is already resting against the back wall. I want to find the right balance of screen size and aesthetics in the room, but I have been partial to the hidden speaker look. The post might be a little long, but I appreciate you hanging in there with me!
From a BOM/cost perspective this is what it looked like for me to build the frame. This does not include tools such as the kreg jig, staple gun, level, etc. as I already owned those tools, but you may want to take those into consideration depending on how you can rationalize tool need versus tool want.