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Lexicon MC-12 and MC-12B
MC-12 & MC-12B New Product Q&A ~ Part Two

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SMR: The addition of component video switching is welcome, especially if one has a suitably equipped display device. Can you tell us a little more about its implementation? For example, are on-screen menus available via the component outputs, has provision been made for a separate synchronisation signal (carried by a fourth interconnect), is any format transposition available (composite to Y/C, component to Y/C etc.,) and perhaps most importantly, does the video circuitry have sufficient bandwidth to accommodate high-definition sources?
Andy Clark: There are four component video inputs. Three with RCA connectors and one with BNC connectors. The output utilizes BNC connectors with 75-ohm impedance. The switcher does not include a provision for synchronization signals, but the composite video switcher could be used simultaneously to switch a synchronization signal. The bandwidth of the component video switcher is not limited and can handle any type of input. It was designed with a wire in = wire out philosophy to retain signal quality. The unit does not include a scaler, so it will not convert S- and composite video inputs into component video outputs. The OSD will function on the component video output as long as there is a 480i component video input signal.
SMR: You mentioned earlier that the MC-12b had balanced outputs; does it also have balanced inputs?
Andy Clark: No. It is always recommended to use digital inputs for optimum performance.
SMR: Can you tell us a little more about the MC-12B's balanced architecture? There have been numerous SMR Forum discussions of late about how not to implement balanced outputs so members will be particularly interested in the Lexicon solution. For example, is the MC-12B equipped with dual differential digital to analogue converters? How does the unbalanced MC-12 differ, is the balanced D/A architecture in place but only driving single-ended outputs?
Andy Clark: Both the MC-12 Balanced and MC-12 use the DACs in dual differential mode for the Main zone. The Main zone DACs output two balanced signals per channel. The positive signal of one is combined with the negative signal of the other reducing noise and improving performance. This signal is then sent to an unbalanced level control to prevent level mismatches from occurring at this stage. We looked at using two level controls per channel to maintain a balanced signal at this stage, but the small variances from level control to level control would have led to level mismatches between the positive and negative signal. The unbalanced signal is then sent to the RCA outputs. On the MC-12 Balanced the same signal is simultaneously sent to a balanced driver which creates a balanced signal for the XLR outputs. This design takes full advantage of the dual differential mode of the DACs without introducing level mismatches between the positive and negative signals of each main output.
SMR: Zone 2 operation has long been a source of confusion for DC- and MC- owners, specifically the inability to output a Zone 2 signal from a digital source whilst simultaneously listening to the full surround experience in the main room. Will the MC-12 address this issue?
Andy Clark: Yes. There are separate digital receivers, Analog-to-Digital and Digital-to-Analog converters for each zone. This eliminates many of the resource issues that were confusing to MC-1 users. We've also made it easier to control the separate zones with a front panel design that provides input buttons for all three zones. The remote control also provides extra banks of commands for easy control of the three zones.
SMR: Lexicon has an enviable upgrade record, the DC-1 is still supported and new formats are always embraced when there is sufficient demand. But perhaps the most annoying aspect of the upgrade process is the need to disassemble one's system and arrange for the replacement of one or more EP-ROMs. Other manufacturers, TAG McLaren and Meridian for example, distribute their software by more user-friendly means. Have Lexicon addressed this issue within the MC-12?
Andy Clark: Yes. The software is contained on a flash memory chip and can be upgraded from a PC via the RS-232 port on the back panel. The flash memory was also designed onto a removable card so the software can be replaced the old fashioned way - by simply replacing the card. This is useful if a PC is not available to perform the upgrade.
SMR: So now we can upgrade the MC-12 using a laptop and RS-232 link? Why has Lexicon's standpoint on this method of operating software distribution changed since the introduction of the MC-1, when the idea was considered and rejected?
Andy Clark: Market demand. Everyone (end users, dealers, installers, and reps) was asking us to provide software upgrades that didn't require system disassembly. We didn't make the change on the MC-1 due to the availability of flash memory - in allocation at the time due to the explosion of mass-market electronics (Wireless phones, PDA's, etc.).
SMR: And on the subject of upgrades, does the MC-12 have a 'card-cage' architecture along the lines of a Meridian 861 or Theta Casablanca? If not, from a hardware standpoint, how do you plan to embrace future technologies, a digital interface for DVD-Audio or SACD for example?
Andy Clark: The MC-12 architecture is expandable. There are three internal connectors for additional boards. It's not a "card-cage" design since that implies PC based architecture. The MC-12 is an embedded architecture of our own design. On the back panel, there is a small removable access panel that allows new input and output connectors to be added should they become necessary for digital outputs on DVD-A or SACD players. Rumors persist that DVD-A players will include digital outputs within two years. One can only hope.
SMR: Speaking of DVD-Audio and SACD, I notice that the MC-12 has a 5.1 analogue input array, obviously largely because both formats require analogue connections if the full resolution of the recording is to be retained. But if a true analogue bypass is to be used, does that also mean that we are forced to bypass the system's bass management and time alignment settings, or can they be applied if one wishes?
Andy Clark:

We included an analog bypass that can be applied to the 5.1 analog input and the stereo analog inputs. When engaged, the analog input is sent directly to the level control and then the analog outputs. This bypasses all of the processing including crossovers, bass management, and speaker distance compensation. If these features are desired with analog inputs, simply defeat the analog bypass and they can all be used.

For a 5.1-channel input, the L-C-R channels are sent to the Front L/C/R outputs, the Surround L/R channels are sent to the Side and Rear L/R outputs, and the LFE channel is sent to the Sub L/R and LFE outputs. For stereo inputs, the L/R channels are sent to the Front L/R outputs.

SMR: And what about Lexicon's proprietary processing modes, would it be possible, for example, to process a 5.1 DVD-Audio source, input via the analogue 5.1 array in Logic 7 mode and take advantage of all the MC-12's available channels?
Andy Clark: For 5.1 analog inputs there isn't any processing available. We do, however, route the surround channels to the Side and Rear L/R outputs and the subwoofer channel to all of the subwoofer outputs to take advantage of the 10 active channels.
SMR: What about two-channel analogue sources, do they undergo A/D conversion?
Andy Clark: Yes, unless you activate the analog bypass. Then it passes the signal directly to the level controls then to the Front L/R outputs.
SMR: You've already mentioned the MC-12's RS-232 serial port and it's role in system software upgrades, but can it also be used for system integration using a Crestron or Panja interface? A small but useful serial control program was developed for the MC-1 by an SMR Forum regular, but from an official standpoint the ports were left floundering by the wayside. Can we expect an improved level of support for the MC-12's RS-232 interface?
Andy Clark: The MC-12 serial control protocol will be provided on our website. It's misleading for a company to "officially" support something that is not an industry standard and is subject to change without notice. We will work with Crestron and Panja so they can prepare control programs for their products. Many installers will also write their own programs. We have received positive feedback from the install community on our implementation of serial control. It works very well, thanks to input from the folks from Media Systems in Boston, MA. We also worked closely with Panja and Crestron to provide them with everything they needed so they could write the necessary drivers to integrate the MC-1 and DC-2 with their respective systems.

Within the SMR (official) Lexicon forum, we've seen a number of questions crop up time and again, so this is probably the best time to revisit some of our old favourites. Does the MC-12 provide:

The ability to toggle quickly between the analogue and digital inputs of any given source?

Andy Clark: No, but the unit will automatically switch to an analog input whenever there isn't a valid digital input.
SMR: The ability to turn THX Re-EQ on and off without entering the THX 'Effect Adjust' menu?
Andy Clark: No, but you will be able to turn THX Surround EX on and off without entering the mode adjust menu.
SMR: The ability to assign custom loudspeaker configurations to any given input - all channels 'Small' with a subwoofer for DVD and the front L/R channels 'Large' without a subwoofer for CD for example?
Andy Clark: No. The crossovers should be set based on the capabilities of the speakers, not based on the input selection. The speakers in a system can either handle certain low frequencies or not. This does not change with input selection. If the goal is to avoid bass management in the processor, then full range speakers should be used for at least the Front L/R outputs.
SMR: The ability to store pre-set listening mode custom configurations (the equivalent of the old CP Series user-banks)?
Andy Clark: No.
SMR: The ability to apply modes such as Mono Logic to 48kHz or even 96kHz material?
Andy Clark: Yes. All available surround modes work at all sampling frequencies.
SMR: And last but by no means least, greater crossover flexibility? Users have often dreamed of a larger number of crossover options, rather than the three (plus full-range) we have within the DC-1, DC-2 and MC-1. There have also been numerous requests for adjustable crossover slopes, is the MC-12 suitably equipped?
Andy Clark: Yes. There are x-overs every 10Hz from 30-120Hz. They are all 24dB/octave except for the THX 80Hz crossover which utilizes a 12dB/octave slope per their specification.
SMR: Finally, when the MC-1 was introduced, Lexicon were already researching small room equalisation but it was decided that the added cost would be prohibitive for a platform retailing around the $6,000 mark. It was being considered as an option however, so now Lexicon have announced a more expensive and more powerful platform, will we also be given the option of parametric equalisation?
Andy Clark: We have received several requests to offer this feature and agree that, if done right, would bring down the final barrier to reference quality playback in most listening rooms. The development would be significant and a business case would have to be approved. This means that the potential market and selling price would have to justify the significant development costs. When there is an installed base of MC-12's and substantial market demand for this, we will make a decision.
SMR: Many thanks Andy for participating in this Q&A. If folks have further questions, they can get in touch either via the Lexicon web site or within the official Lexicon discussion and support forum:
Go Back To Part One

If you have comments, questions or suggestions for Lexicon about the new MC-12 and MC-12B visit the SMR Lexicon Discussion & Support Forum!

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