App Note:
Design Your Own 4-D Theater
Ten Easy Steps

4-D theaters offer many benefits to museums and other small and medium-sized venues: they're affordable, they're flexible, and they generate high guest satisfaction ratings. In short, a 4-D theater maximizes your return on investment. It's also possible to start small, and – as budget permits – gradually add features, such as better seating, in-theater special effects and so on.

Here's a step-by-step guide to designing your own 4-D theater.

Director
Alcorn McBride France

 
Equipment
Audio Digital Binloop
Video DVMHD
Lighting DMX Machine
Show Control V16+
WEBster
Software
Binloop Config
WinScript

Step 1. Select Your Media.

What is your show about? Will it change during the season? Will there be different presentations throughout the day? Showscan, Iwerks and Simex are just a few of the many providers of 3-D and 4-D films available to you. There are also independent producers. Or, in this day of powerful PCs and home-based graphics designers, you can even have your own custom film made, probably cheaper than you'd guess. A good place to start researching is the TEA's website at themeit.com.

Beginning the installation

Step 2. Identify Your Space.

The ideal theater space is one that is already dark, and that has a high enough ceiling to allow for a good-sized projection screen. Including aisles, you'll need about one square meter for each seated guest, or about half that if guests will stand during the presentation. Polarized screens are quite directional. The first row should be no closer to the screen than about 0.6 times the screen width, the last row no more than 2.2 times its width. Allow at least five inches of height change per row to provide adequate sight lines.

If your ceiling height and budget allow, you can raise the floor at the rear of the room (which means you'll need ramps outside the theater) or you can put in stand-alone stadium seating. Don't forget to allow space for wheelchairs. Try to envision guest flow. Separate entrances and exits work best, and people move faster if the floor slopes downward. Three minutes of extra "fill/spill" time can cost you 20% of your investment -- more if your film is short.

Step 3. Select Your Seats and Effects.

The seats for 4-D theaters may be individual or grouped. They may be hydraulic, pneumatic or electric. Electric models simplify installation and maintenance. Often, the seats contain special effects devices such as leg ticklers or air jets.

Strobes, water sprinklers, and fog are all popular 4-D theater effects. Most can be installed at minimal cost. Careful selection and programming of your show control system (see below) is essential, as a stuck water valve can ruin a theater – or even a building. Alcorn McBride and your audio/video integrator can help prevent such disasters.

Step 4. Treat The Room.

With modern video projection, there's no longer a need for a separate projection booth, so finishing the space consists mostly of painting it black. But there's one important step that is often forgotten, and that's applying appropriate acoustic treatment. The cost of an acoustic consultant is money well spent, but it's also not that hard to do it yourself.

Dimensions of space are relatively modest and the required goal is to make the room pretty "dead" acoustically with a very short reverberation time; any desired "live" characteristics can be added electronically in the sound distribution chain . Inexpensive foam and other sound deadening panels are available through most audio/video suppliers. The back of the screen must also be treated, with a baffle the size of the screen.

The sound system is identical to that of a movie theater. It's best to stick with the bi- and tri-amplified systems traditionally used in movie theaters, like those of JBL. Note that the enclosures behind the screen can be very bulky. Low frequency reinforcement is particularly large, but important. The number of speakers must be sufficient to ensure a homogeneous coverage of the seats. In the systems we design, each enclosure is fed by an individual amplifier channel. This allows precise adjustment and future changes.

The screen is installed on a framework generally fixed on the wall or the ground (or both). The fabric is pierced with small holes in order to allow the sound from enclosures behind the screen to reach the guests. The metallized fabric used for 3D is very fragile, so beware of vandals! It's best to locate the screen where it can't easily be accessed.

Wiring the rack

Step 5. Select Your Projectors.

While it's still true that you pay for resolution and brightness, the cost of digital projectors has plunged in the past few years, so it's tempting to rush right out and find a great deal. There's an important requirement for 3-D projection that you need to keep in mind, though. For the 3-D effect to work, two projectors must work together flawlessly, delivering the image through polarizing lenses set at right angles to one another.

The bad news is that their price increases exponentially as a function of image size. The other bad news is that the 3D filters in front of the lenses filter part of the light, so you'll need projectors even more powerful than for a traditional theater. The traditional manufacturers are Barco and Christie. A good projector should provide even illumination, with no hot spots.

The projectors must be adjustable to the exact same rectangular boundaries, and must repeatedly fill that rectangle, even after months of use and many power cycles. Audio/video contractors such as RK Roden routinely work on projects with these constraints. It's best to leave the integration to such a company, because they will mount the projectors, calibrate them, and guarantee their correct function. Your integrator can also specify the screen material, which must accurately reflect the polarized light, without scattering it.

Plan on replacing both lamps at the same time, and within the limits recommended by the manufacturer. A lamp which explodes can cause major damage.

If your projectors are in a separate projection room, the window between this room and the theater needs a "port" made from special glass, made by companies such as Amiran de Schott.

The finished rack

Step 6. Select Video Sources.

Because you want to offer your guests a high quality image they can't find at home, your video sources should be high definition. You'll also want them to operate at the highest possible bit rate, as this affects the clarity of identical sized images – the higher the bit rate, the sharper the picture. Be careful to choose HD sources that are guaranteed to run in frame sync – most aren't. Alcorn McBride's Digital Video Machine HD is designed to precisely sync, and it operates at more than twice the bit rate of high-definition broadcast TV.

Step 7. Select Your Audio Source.

4-D theaters require surround sound to take advantage of the 3-D effect. The least expensive way to achieve this is by using a Dolby 5.1 decoder connected to your HD source. The decoder feeds analog audio to amplifiers, which distribute sound to the theater speakers. (See our theater application note for more details.) Significantly better sound – and more channels – may be achieved by using Alcorn McBride's Digital Binloop to source discrete audio tracks directly to the amplifiers. The Digital Binloop may also be outfitted with video cards for use in the preshow (see below).

Step 8. Select a Control System.

Operating a 3-D theater is a bit trickier than just pushing the start button on a DVD player. The left and right media must be started in precise sync, and remain that way throughout the show. Even boardroom control systems such as those made by Crestron and AMX are not designed to do this. Alcorn McBride's control systems are locked to the video clock, so we can guarantee perfect frame sync every time. That's why they're the standard throughout the world's theme parks.

Step 9. Consider a Preshow Area.

If your show will run continuously during busy periods you'll want a preshow area where guests can wait for the next show.

Preshows have many advantages. They familiarize guests with the topic and characters of the film they will see, lending the attraction more impact. They provide an environment for giving instructions about entering the theater, which accelerates the process and maximizes capacity. They provide a space for advertising or sponsorship, and important revenue source. Finally, they can be illuminated at a reduced lighting level, allowing guests' eyes to partially adjust to theater conditions in advance.

The preshow area should be about one fourth the size of the theater. Consider providing static displays or orientation video in the preshow area. With control and audio/video equipment already in place for the theater, the additional cost for a preshow is minimal. You should also provide a countdown clock to display the number of minutes until the next show. This can be an LED light bar connected to the theater control system, or it can be captioned right onto the video program.

The finished theater (as viewed without 3D glasses)

Step 10. Train Your Staff.

Would you agree to pay 20% more for your theater? Of course not. BUt that's what a poorly trained staff can cost you in terms of throughput. Enthusiastic, well-trained personnel can maximize both your capacity and your guests' experience. And well-trained maintenance personnel will keep your attraction operating perfectly, so that your investment is protected.

With careful planning and selection of the right equipment and vendors, your 4-D theater will be open in no time. You'll find it brings your guests back time after time for the exciting and unique experience it offers. Oh, and don't forget to take the time to enjoy the show yourself, once in a while, too!

If you have any questions, or would like to discuss your theater design with us, please give us a call.

See the finished Bellewaerde Theater in Case Studies.





3300 S. Hiawassee Rd.
Bldg. 105
Orlando, FL 32835


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