Lexicon MC-12 surround-sound processor Page 2

Inside, the MC-12 uses 24-bit/192kHz D/A converters—two for each channel, which Lexicon says increases the signal/noise ratio by about 3dB over the use of a single converter. Four powerful SHARC 32-bit DSP engines are used to process most surround modes, though an additional Cirrus Logic Crystal chip is used in conjunction with the SHARC chips to decode DTS, DTS-ES, Dolby Digital, and Dolby Pro Logic II audio signals. Lexicon points out that three internal expansion slots provide the opportunity to add processing capability for almost any number of surround modes that might come into play months or years from now—including, perhaps, modes that take advantage of the two additional Aux output channels the MC-12 offers. (Like its predecessors, the MC-12 does not include a Dolby Digital demodulator for laserdisc players; Lexicon has long sold an external demodulator.)

The DTS ES processor (which offers a 6.1-channel setup, including provision for a rear center channel) supports both varieties of the new format, matrixed and discrete. Not included at present is DTS Neo:6, which reformats a 2-channel signal to a 5.1- or 6.1-channel audio stream, just as Dolby Pro Logic II and Lexicon's own Logic 7 formats do. Andy Clark says that the Neo:6 software upgrade will soon be available for free (though Lexicon believes its own software, already included, does the job better).

Incoming analog audio signals are converted to digital (unless the analog bypass is used) at 24 bits/96kHz, and the signal is processed in that format no matter what is done with it thereafter—passed out as a stereo signal or run through one of the surround matrixes. Lexicon says DADs (2-channel discs recorded at 24/96) are accepted at that format and processed all the way through in the same resolution—once again, no matter whether they're played back in stereo or in a multichannel format.

Many MC-12 buyers will likely opt for one of those third-party do-all, touch-screen remotes often found in upscale home theater systems. While the remote that comes with the processor is a generally flexible and completely backlit number that works quite well, I liked the MC-1's remote better. One feature of the older model that appealed to me was an oversized, glow-in-the-dark button that turns on the remote's backlight. You can't miss it in the dark, and once it's pushed, everything else is readable. The MC-12 remote's light button is a tiny one at the top left corner. The new remote's light comes on if you press any button—but that means that if you can't remember where the light button is, you could change inputs or affect formats or something else unintended while trying to turn on the light. It's a small complaint; otherwise, the new remote is perfectly fine.

A Shift button allows users to access a host of additional commands—for example, pressing both the Shift and THX buttons turns the EX parameter on and off. Several pages of the instruction book list all of these Shift commands; it would be almost impossible to remember all of them. The MC-12's rear panel includes ports for wired control.

I've had an opportunity to have a look at several high-end processors in recent months, including the Sunfire Cinema Grand II (reviewed in the September 2000 issue) and Theta Digital's Casablanca II (reviewed by Fred Manteghian in July/August 2001). Both of those have their benefits and liabilities, but the Lexicon MC-12 handily bettered both of them—and any other I'm familiar with—in at least one area: ease of operation. The Sunfire I found less than intuitive in setup and a bit quirky in use. The Theta was a bear to set up. In fact, you should ask your dealer to do it. And unless you love this kind of tinkering and dependence on a book-length instruction manual, once the Theta is set, don't try to change it.

The Lexicon, on the other hand, was a dream to set up and use. For one thing, the front panel has a button for everything, something neither of the other processors offers. If you want to record the signal from your CD player, simply press the CD button in the Record bank on the front panel. When pressed, the button lights up. What could be easier? Offering dedicated input buttons for all of the Zone 2 outputs greatly simplifies this feature, which allows you to use the processor for speakers in a second room. (On Lexicon's older processors, the Zone 2 feature was always confusing.) And the onscreen menus for installation, setup, and system configuration are thoroughly intuitive, though the MC-12 offers many more options than its predecessor. Some of them sent me to the easy-to-use instruction book to determine what they did.

One complaint: If you use component video as your main output on the MC-12, the onscreen menus are virtually useless for everyday use. On older Lexicon processors and the MC-12, you're given the choice of overlaying the onscreen menus on a full-screen blue background or as white letters painted over the program material. Obviously, the second option is far less obtrusive. But when you use the component outputs, the unit allows only the full-screen blue option. That makes no difference during setup, but if you're watching a movie, say, and decide to turn up the volume, the Lexicon will overlay the entire screen with a bright blue background, showing the volume-control bar graph at the top (or middle or bottom, as you choose). After two seconds, the blue screen will fall away with a loud click of a relay in the processor. All that is obtrusive and unacceptable.

Lexicon's Andy Clark acknowledged the problem but said they had no choice. The component signal is actually three different signals, so it was impossible to mix the onscreen message text with the video. (The older processors lacked component-video inputs and so didn't have this problem.) When designing the machine, he said, Lexicon had the choice of offering this flawed onscreen menu—or of not offering onscreen menus at all for the component output. Clark said the company considered the latter option, but decided users would appreciate having the onscreen menus during setup. That's what I concluded as well.

Of course, you can always use the setup menus (or ad hoc, with buttons on the remote) to turn off the onscreen menus so they never appear. In fact, because of the limitations described above, the MC-12 comes with the menus turned off in the component mode. If you're using the component outputs, you'll have to run through the setup menu on the front-panel display to activate them. This can be a bit confusing, given the limited size of the screen.

Moreover, the component inputs provide an onscreen display only with 480-line interlaced signals because the internal signal generator uses only that format. The component inputs and outputs can handle any sort of signal now available, such as 480-line progressive or even 1080i HDTV, which means you can route those signals through the processor for switching like any other. But with those higher-bandwidth signals you won't have access to the onscreen display. Still, even with these limitations, remember that front-panel messages mirror the onscreen displays. (HD and 480p signals can't be fed through the S-video or composite inputs, so this limitation is not a factor with those.)

A trickle of surround receivers is just beginning to appear that incorporate internal video decoders—devices that convert both composite and S-video signals to component, so that only one set of (component) leads is needed to route signals from the receiver to the video display. But the Lexicon does not have this feature—nor does any other surround processor we know of at this time. You'll have to use separate component, S-video, and possibly composite connections from the Lexicon to your TV, video processor, or whatever, if you have sources using each of these output formats. This means that every time you switch between devices using the different outputs, you'll have to change inputs on your TV, video processor, or whatever. That could be a minor inconvenience.