Because the color correction system outputs four pairs of AES audio, a D to A converter is required for audio monitoring. Audio delay is also needed, as nearly all DLP video projectors are usually three to four frames behind the audio, and LCD monitors can be up to two frames behind, due to video processing requirements. To handle these needs, Pell installed a Lucid 88192 A/D and D/A converter and three Symetrix Deuce 722 digital signal processors in the audio path. These devices transparently solved these problems to deliver pristine frame-accurate audio.Only a few years ago, Pell would have specified a digital delay to solve this problem, but with the tremendous advances in DSP technology, no one makes a delay-only unit any more. After a little bit of research, Pell discovered that Symetrix has engineered the perfect solution.
The Symetrix Deuce 722 is a modest DSP unit with two inputs and two outputs that contains the most frequently used processing blocks found in their SymNet brand of full-blown, open-architecture DSP systems. And among those blocks, of course, are the simple, but wonderfully accurate delays he needed. Using his laptop and an Ethernet interface, Pell programmed the three 722s to deliver a fully coherent 5.1 channel delay. Critical to allowing the room to operate as either a color correction suite or a theater, the 722s also include user presets for easy switching between the Cine-tal (1.5 frames delay) and the SIM 2 HT-5000 (4 frames delay).
"The Lucid 88192 is stunning," said Pell. "It's like there's no conversion going on at all, and the system now has the flexibility to route any source to any destination, regardless of the format." The 88192 smoothly handles 192kHz sampling rates with bit depths up to 24 bits, and boasts eight analog inputs, eight analog outputs, four pairs of AES/EBU digital inputs and outputs, two ADAT light pipe inputs and outputs for all channels, and word-clock inputs and outputs. Input formats are user-selectable in pairs and all outputs operate simultaneously. "A true Clydesdale workhorse of digital audio!" adds Pell.
The Pablo Systems SIM 2 HT-5000 projector contains three sophisticated DLP chips with capabilities that underscore the fact that today's technology is the stuff of last decade's science fiction. Each chip contains nearly one million tiny mirrors that physically move to project the stellar image that is the hallmark of these projectors.
Providing a true, reliable reference for the image color is the job of the Cine-tal Cinemage LCD display.
"These timing issues will continue to pop up," remarked Pell, "so it's nice to know that there is a simple, inexpensive, and, yet utterly, professional solution. I plan to use the 88192 and 722s in all my future designs. And although this room didn't call for it, the 722 has a ton of filtering and equalization capabilities so I can tune future rooms without any additional outboard processors. That will save my clients money and make my job much easier!"
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