How-To: Build yourself a front projection home theater

In today's How-To we get to play with other people's toys. We upgraded a home theater to a high definition front projection system. We lay it out, set it up, drill holes, nearly die in a Texas attic, and bring home the popcorn.

Our project home theater already has the essentials for taking advantage of a high definition display: a progressive scan DVD player with component video output and a hi-def DISH Network satellite receiver provide a HD video source for the projector.

Screen Selection
It may seem counter intuitive, but it's helpful to consider (but not purchase) the screen before choosing a projector. Knowing the size of screen you want in your room will determine where the projector needs to be mounted, and how bright it needs to be. If you're not sure, marking out the dimensions of the screen with some blue masking tape and checking out the view from your seating area can be helpful. Click on to read the rest of this week's How-To! 


It's wise to consider the content you intend to view when choosing your screen. 16:9 (the ratio of width to height) is standard for HDTV content as you well know. The widest movies are presented in 2.35:1 format; standard definition television is 4:3. We've drawn these as constant height, just to give a rough idea of the differences. Check out the Letterbox and Widescreen Advocacy page for a great explanation.

After a few days of debating, the owner of our project theater determined that he wanted a 100 inch diagonal (49 x 87-inch) 16:9 screen. 



The projector is the heart of any projection system. We selected the Panasonic's PT-AE900U high contrast LCD projector. It displays 1280 x 720 resolution and has plenty of inputs (2 component, HDMI, VGA, S-video, etc.) and a great user reputation. The $400 rebate from Panasonic makes it even more attractive to the bargain hunting AV geek.



The screen size you want will determine how far away the projector needs to be mounted. This information is usually found in a table in the projector manual. Calling the manufacturer or downloading the manual is a good way to get this information. According to this table from the manual, the zoom range of the lens allows for a flexible 10 feet 2 inches, to 20 feet 4 inch distance from a 100 inch screen.

Before ordering your screen, we suggest getting your hands on the projector first to test out the size you're considering with a temporary screen (aka bed sheet or wall), and the lighting conditions you intend to use it under. If you can't put up curtains, a brighter room may call for a less reflective (lower gain) screen to get the best picture.



We finally settled on a Da-Lite Cinema Contour 16:9 100-inch diagonal  wall mount screen. This screen has a gain of 1.3 (it will reflect 1.3 times more light than a standard white surface) and comes with a 3-inch wide matte black frame with permanent wall mount brackets.



It's important to keep eye height in mind when mounting a screen. Have a seat and measure how high your eyes are as you look straight ahead. 



Subtract 1/3 of the screen height from your eye height. That should be the height of the bottom of your screen. (Add the screen height to that to get the top of screen measurement.) [Update: Quick fix on the math photo. Thanks Dignan17]



Mounting the Da-Lite screen is simple. We used 2 inch drywall screws to mount the upper and lower brackets. Once the first screw is in, use a bubble level to level the screen mount. Thanks to our stud finder, we managed to secure the brackets to three separate studs.



The screen fits over the top bracket, is centered, then the bottom of the frame just pops over the lower bracket for a nice clean installation.



Since the room is about seventeen feet deep, we decided to mount the projector on a shelf. A ceiling mount was an option, but the shelf was easier and cheaper to install for this project. The shelf was leveled and centered on the back wall four inches lower than the top of the screen. The Panasonic can be located off center, but keeping the image centered in the lens will produce the best image. It's important to place the projector as parallel and level to the screen as possible.




Having attic or basement access to run your cables is a must if you want to hide you cables. Just remember that attic space in Texas gets seriously hot later in the day (as we found out). We pulled our cables from an access box near the equipment rack, through the attic, down to our freshly cut hole for the projector.



Once you have access into the wall and through the top or bottom of the stud wall, a wire snake is great for fishing access through the wall. For ease, we pulled a light nylon line through the wall and tied that to our bundle of cables to pull them through the wall down to the plate.



For the DVD player, we made a set of components; for the Satellite receiver, we purchased a 35 foot DVI to HDMI cable. Because the HDMI cable is so thick and lacks any method of securing the cable (dear HDMI designers: what the hell were you thinking?), we cut a new box hole directly behind the future location of the projectors HDMI port. We also pulled the power cable through the wall to the projector -- it's connected to a dedicated outlet installed in the attic.




We had problems getting a component cable in time for the install, so we tried making our own from shielded cat-5 and a set of RCA ends. It can be a challenge getting good solder type connectors, so we sacrificed a prebuilt cable to get a set of color coded, machine terminated connectors.



We used three pairs of the cat-5 for our component cables and left the shielding disconnected. Heat shrink tubing was used to insulate each connection as it was built, and the entire assembly was covered in heat shrink tubing to finish off each cable end. For ease, we finished the other end of the cable after we pulled it through the walls. The final cable performed just as well as our shorter cable, but we suspect a high end cable would provide slightly better video quality.





The adjustment joystick on the Panasonic could be smoother, but with the right touch, you can align the image pretty decently with it. The ring behind the lens zooms the image and rotating the lens itself focuses the image. We wish these controls were electronic, but once it's set, you can forget about it.



Once the projector is connected, powered and aimed, take the time to calibrate it a bit. The AVIA Guide to Home Theater on DVD is an excellent tool for calibrating the video your projector displays. It's a bit on the Mr. Rogers cheesy side, but it's loaded with test patterns and tones for tuning your setup. Some of it is specific to the older CRT systems, but with it you can calibrate your video to meet NTSC standards. The colored filters (Gels) are used for blocking out the other colors so the levels of red, green and blue can be adjusted individually. Even with the great ratings of the Panasonic AE900U we used, it was very helpful for calibrating contrast and just a bit of color level tweaking.




Finished up, and tweaked with AVIA, we're getting the popcorn and kickin back. It was a hit with everyone, even a uh, friendly scorpion (with claws and stinger) came by to check it out. We kid you not. Texas, man, Texas.

Source Link- http://www.engadget.com/2006/05/23/how-to-build-yourself-a-front-projection-home-theater/