Lexicon DC-1 Digital Controller/LDD-1 Dolby Digital Demodulator.

Manufacturer: Lexicon, Inc., 3 Oak Park, Bedford, MA 01730-1441; 781/280-0300

Price: DC-1, $4,995 (as tested, see text); LDD-1, $700

Source: Manufacturer loan

Reviewer: Howard Ferstler

One of the most interesting things about high-end audio is the penchant many enthusiasts have for diddling with their systems. The urge to diddle is a strong one, and I think I have discovered a device that will not only allow many enthusiasts to experiment, but will also allow that kind of playing around to deliver genuine benefits. In addition, I am talking about a component that will allow those who are not much interested in diddling (provided they ate willing to put up with a rather involved set-up procedure at the beginning) to enjoy audio and audio-video sound that just about defines the state of the art.

The Lexicon DC-1 has been on the scene for a couple of years, and in its primary incarnation is a rather basic, preamp/surround-processor unit (admittedly, with four surround channels, rather than the usual two), with Dolby Pro Logic decoding for movie use and a series of workable, DSP-generated hall, nightclub, and church simulations for audio-only use.

A more upscale model has been available with THX emendations for some time also, and then a still more advanced, Dolby Digital version was released. The basic version has a list price of about $2,000 (not bad for an upscale surround preamp), with the THX addition bumping the price up to about $3,000, and the DD addition running that on up to a rather heady $4,700. The more advanced THX/DD version also has some interesting DSP emendations for use with movie soundtracks and audio-only recordings that are in a class by themselves when it comes to producing a theater-like or music-hall environment in the home. This explains the rather substantial price jumps beyond that of the basic unit.

The latest version, which I am reviewing here and which retails for just under $5,000, not only has all the amendments noted above, but also incorporates DTS audio decoding.

Yes, DTS audio is here, and the DC-1 may be the best way serious enthusiasts will be able to enjoy that technology to fullest. I should point out here that if you decided to get one of the lesser-equipped versions (say, for example, you want to wait to see if DTS really takes off or is simply a flash in the audio pan, or if you opt for the absolutely basic preamp/processor version and then later on, after coming up with a winning lotto ticket, decide to go all out for home theater), you can take it back to your local Lexicon dealer to have it upgraded to any of the more advanced configurations. As best I can tell, the unit is modular enough to be further upgradable to even more advanced digital-surround discoveries in the future.

As I noted, the trait is more than just a surround processor. It is also an audio-video signal switching and routing device that can take the place of a typical outboard preamp. It does not have a phono preamp stage, which may limit its abilities in some circles, but it certainly does not limit them for me. While it does not have as many audio and video inputs as some other processors out there, the ones it does have allow a very high degree of signal routing and switching options.

The DC-1 has an impressive set of basic-audio specifications: eight analog-audio inputs (100,000-ohm input impedance), five composite video inputs, three S-Video inputs, four digital inputs (two coaxial, two TosLink), eight audio outputs (left, center, right, side left/right, rear left/right, and subwoofer, all with 100-ohm output impedances), two video outputs, plus outputs for analog recording, in addition to outputs for a second-zone system in another part of the house.

The processor does not have an on-board Dolby Digital RF demodulator, which is necessary to play the Dolby Digital tracks on AC-3 coded laserdiscs. For that job, you will need to get an outboard unit, such as Lexicon's own LDD-1. This LDD-1 worked flawlessly for me, but I should point out that many other, often lower-priced, brands would probably function just as well.

The processor sports 20-bit Delta-Sigma converters [current production models now have 24-bit converters. - KWN], for hookup to all but the most arcane digital transports, has a rated frequency response of 10 Hz to 20 kHz, has a rated harmonic distortion of less than 0.01 percent, has a signal-to-noise ratio of at least 90 dB, consumes 35 watts of power, and weighs in at a modest 10.5 pounds (4.8 kg). The dimensions are 17.3 inches wide, 3.6 inches high, and 11.5 inches deep. The DC-1 comes with a remote control that is actually easy to use, once the device is fully set up, if only because it is not encrusted with a multitude of keys. Movie buffs might note that the remote does not have a backlit feature, however.

As indicated, the DC-1 is both a diddler's delight and an audio curmudgeon's way to enjoy music as never before. However, those who do not care to diddle are still going to have to do a bit more when they first fire it up than simply sit back and listen. This is not some kind of easy-going, turn-on-and-listen piece of hardware. The old days are over.

Indeed, this DD/DTS version of the DC-1 has a somewhat elaborate set-up procedure that involves not only adjusting the initial surround levels, but also involves adjusting for listener-to-speaker distances, setting up the remote-zone feature, adjusting for different speaker types and sizes and crossover points and slopes, assigning surround modes to different inputs, assigning input names, assigning a proper speaker angle and listener position for the Panorama mode, adjusting the subwoofer peak limiter, setting up the A/ V sync delay (possibly needed if you employ a line doubler with your set; although I have one and found the delay necessary), and assigning or changing any frequency-response slope or loudness-compensation emendations felt to be necessary.

Doing this kind of complex set-up can be accomplished by utilizing the two-line display on the processor's front panel. However, for those who are not adept at such things, doing this way may seem as frustrating as working a Sanskrit crossword puzzle -- because you can only see one selected item at a time on the smallish panel. Going from one to the other is a hit-and-miss operation, although Lexicon provides a short, printed "quick reference" sheet that will help you navigate in the proper directions. Nevertheless, the job is much easier to do if a TV monitor is employed to display the DC-1's extensive on-screen menus, because you can see whole sets of options at one glance, and scroll through them as required. Once you have become familiar with the unit, the panel readouts will be more than adequate, and you should not find it necessary to always trim on your TV to configure the unit to play audio-only recordings.

When first shipped, the DC-1 has a set of default values assigned to each user-selectable effect. According to the company, those values were determined to be suitable for a wide variety of average home-theater and home-listening environments. However, as the operator's manual notes, each environment has its own unique set of characteristics, and listeners will also have their own ideas about how they want things to sound. Consequently, you can modify each effect, and can compare your modifications to the factory-default settings. This shows whether what you have done has improved things or created an acoustic mess. All changes can easily be deleted.

[ILLUSTRATION OMITTED]

All upscale surround processors have program-customizing features of some kind, but unlike some of them (for instance, the Yamaha DSP-A3090, which I own and reviewed in Issue 65, and the A3090's replacement, the DSP-A1, which I review below), the DC-1 is not loaded down with a huge number of elemental adjustments that tempt the user to get involved in experiments that will not pay off. While the DC-1's initial setup procedures look daunting, they are really not all that complex, and after a bit of time one should find the trait to be spectacularly easy to work with. The on-the-fly adjustments it offers once the initial set up is completed are exactly what you need to fine tulle assorted recordings and movie soundtracks.

Like all components, the DC-1 comes with operational instructions. These include the quick-reference sheet, a "Design and Theory" booklet, a basic owner's manual, and a specialized addendum for the DD/ DTS version. (Some of the DD material is also included in the basic manual.)

Before turning the unit on, it is important to carefully read the owner's manual. However, this book may be a tough read, and so I suggest that before tackling it the 'new owner carefully read the Design and Theory guide. These two books are probably the best short introductions a layman will encounter that deal with the complex job of simulating a live-performance milieu with a home audio-video system. Not only are all performance aspects of the processor discussed, but the reader will also receive a good background review of concert-hall and movie-theater acoustics.

Once you begin to fool with the processor and then go back into the manuals, the intuitive nature of the DC-1 will become more apparent, and in a short time you will be scooting through the menus as you learn more and more about how the device works. In addition, each scooting session will help to teach you more and more about why audio systems sound like they do, and also make you more appreciative of what this device is capable of.

The DC-1 works best with eight speakers: left, center, right, left-side surround, right-side surround, left-rear surround, right-rear surround, and subwoofer.

Unlike the Yamaha processors, which have their four surround speakers preferably located in the four corners of one's listening room, the Lexicon unit works best with one pair of surrounds located to the sides of the prime listening position, 90 degrees to the left and right of the front-center speaker, and with a second pair located somewhat to the rear, ideally with each angled at about 150 degrees to the left and right of the front-center speaker. (This would be 30 degrees to the left and right of directly behind the listener.) This side/rear positioning is essential if you want some of the more specialized abilities of the processor to work to best effect.

OK, now that we have discussed the preliminaries, I want to give you a listing of the assorted "effects" the DC-1 can deliver, along with some of the manufacturer's comments, plus some comments of my own.

The unit has four DSP synthesizing modes, designed specifically for music listening: Nightclub, Concert Hall, Church, and Cathedral. All employ all four surround speakers, as well as the left and right mains, and all also blend the center speaker into the mix, although its output here is a simple L+R addition, and not a simulated discrete mix, such as what Dolby Pro Logic, or several of the other DC-1 music and movie modes, can deliver.

As one might expect, the biggest difference between the four involve the perception of room size. I found Nightclub to be quite good, although I felt that with some program material it was not markedly superior to either the Cellar Club simulation in my Yamaha DSP-A3090, or the Village Vanguard simulation available with the newer Yamaha DSP-A1. With some small-scale material, however, I felt it was better sounding than any of the other effects the DC-1 offers. Concert Hall was fairly reverberant, considerably more so than most of the concert-hall simulations available with the DSPA3090, and way more than most of those the DSP-A1 offers. Church was also pretty lively, and Cathedral was extremely large in scale.

In each case, I found that in my listening room it was desirable to turn down the surround levels a bit. This is easily accomplished with the excellent DC-1 remote control, and the need to do this kind of thing will certainly vary from listening environment to listening environment, and from recording to recording. I should also note that I have found it necessary to attenuate most of the preset, music-program surround levels of my DSP-A3090, as well, meaning that some of this criticism may simply involve my taste regarding desirable surround-ambience levels.

In addition to the speaker-placement differences, the DC-1's hall/club/church-simulation modes differ from the Yamaha approach in another big way: while the Lexicon reverberates and sends to the surround channels the hard-left and hard-right signals, as well as the phantom-center (L + R), and stereo (L - R) signals, processing them in full stereo, the Yamaha processors I have dealt with only reverberate and send copies of the hard L, C, and R signals to the surround channels. With the Yamaha processors, the pure, 180 degree out-of-phase, L minus R signals are not allowed to be reverberated and sent to the surrounds at all.

In addition, the DC-1 also appears to reverberate the front channels somewhat, whereas the DSP-A3090 and DSP-A1 mostly leave the signals going to the front channels unaltered. I assume the Yamaha idea involves minimizing any redundant reverberation as much as possible both up front and in the surround channels. The differences between the units, while often subtle with musical program material, are readily apparent when you feed them test-tone signals, such as will be found on the Delos Surround Spectacular test disc (DE3179).

Unlike the DC-1, most of the Yamaha DSP hall/room simulation modes do not include the center channel. However, a center fill, even a simple L+R integration, such as what the DC-1 offers with these particular programs, can help imaging considerably. In addition, the DC-1 allows you to independently preset center-channel levels for each effect, whereas with the Yamaha units, the center level in the movie-surround and concert-video modes that do employ the center channel can only be set globally. With the Yamahas, you can change the center-channel level in a given mode, relative to the other channels, but in doing so, you change the center levels in all the other modes by the same amount. This is awkward to deal with.

One might think that this different approach to DSP synthesis would result in radically different sound between the Lexicon unit and the Yamaha models. However, while there are differences, particularly when listening from off-axis somewhat (an advantage of the center-channel fill), and certainly with the test-signals noted previously, the reverberation already on the majority of musical recordings tends to mask the differences to a surprising degree. Once the surround levels are adjusted to good taste, both approaches work quite well, even though the surround-speaker layouts for each system are quite different.

The DC-1 has three other music-oriented functions that I found to be interesting, and possibly superior to the straight DSP versions noted above.

One, Panorama, works similarly to the well-known Carver Sonic Hologram, crosstalk-cancellation process, and is also acoustically similar in subjective behavior to what is accomplished by the Polk SDA speakers. (The concept was worked out well before Carver and Polk, with an early implementation being patented by B.S. Atal and M.R. Schroeder in 1966.) Panorama is different in several ways, however. First, the center speaker is active, which provides a bit of center fill. Second, the surround speakers are also active, helping to fill out the room space behind the listener. Third, the cancellation signals themselves are also canceled by additional cancellation signals, which tends to tighten up the effect somewhat.

Panorama will not be everyone's cup of tea, although I rather liked what it could do with some recordings. (I had a Carver processor for years, and found it to often be useful.) It can expand the soundstage to often very wide, front-row perspective dimensions, and with some program material, particularly headphone-oriented binaural recordings, this can be exciting to experience. I will note that when I tried it out on my wife with normal, stereo recordings she complained about a feeling of pressure on her ears, and I have heard similar complaints from others. The somewhat phasey quality of the cancellation signals can do that to certain people. In addition, with some conventional program material Panorama can deliver a soundstage that is just plain too wide.

I found the two remaining functions to be the best of the lot for music-playback situations with most two-channel source material. Music Surround, which is only available on the THX and Dolby Digital versions of the DC-1, passes unprocessed left and right information directly to the left and right speakers, just as the Yamaha processors do in their hall-simulation modes. As with the DSP modes discussed previously, it also sends, a low-level, but un-steered, L + R signal to the center speaker, to act as a center fill.

However, the surround signals are not DSP-generated. What the surround speakers get is basically a copy of what is sent to the front speakers, somewhat delayed in time, and probably filtered to an extent. At times, they also seem to be slightly reverberated. The signals going to the rear surrounds are also delayed a few more milliseconds (by an adjustable rear-delay offset feature) than those going to the side surrounds. The result is an uncannily effective recreation of the stereo space of the hall where the recording actually took place, particularly if the listener sits fairly close to the usual sweet-spot location.

To my way of thinking, an even more effective music-only mode with many recordings is Music Logic. Also only available in the THX and Dolby Digital versions of the DC-1, this function combines unprocessed left and right channel signals with a carefully "steered" center, resulting in the best simulation of three hard front channels from two-channel source material I have heard, particularly with pop music. The well-controlled steering, similar in concept to what is employed with Dolby Pro Logic, only much better adapted to two-channel material, is especially effective if one is listening from off the sweet-spot axis.

With Music Logic, the surround channels get the same kind of stereo treatment as the Music Surround mode offers, although according to the owner's manual, this does not include the rear-delay offset feature, and the surround outputs do not seem to be reverberated. With a stereo pink-noise input, I also measured lower outputs from the side and rear surrounds, compared to Music Surround. Because of this, differences in surround ambience between the two functions were occasionally audible. At times, Music Logic seemed to have the uncanny ability to make a two-channel recording actually sound like it was a seven-channel program. The effect varies with the software, as well as with the way the speakers are positioned.

Lexicon thinks enough of Music Logic to make it the default setting for the CD input of the processor (you have the option to easily change this if you wish), and I can certainly see why. With two-channel source material, it is undoubtedly offers the best three-front-channel simulation I have ever heard from any processor, including what is available with either of the Yamaha DSP-A3090 or the DSP-A1 "Concert-Video" modes, which utilize their own brand of center steering.

Unlike with Music Logic, the Yamaha functions have a tendency to occasionally collapse the soundstage into the center speaker, particularly with pop music, or any acoustic-instrument material that does not have an inherently wide soundstage with a lot of hard-left and hard-right imaging to begin with. Music lovers might be inclined to consider the Music Logic function to be the most important feature the DC-1 offers. I would be hard pressed to disagree with them.

In addition to the music modes, the DC-1, of course, also offers a number of home-theater effects of very high quality. The standard, two-channel-input versions are based on the Dolby Pro Logic parameters most of us are by now fairly familiar with. Aside from basic Pro Logic decoding, the unit also includes the required THX emendations, but it also allows the user to modify those by offering the option of using monopole or bipole surrounds, rather than dipoles.

If the latter are chosen, the surround speakers are best located at the sides, in the well known THX manner, and the rear surrounds are inoperative when the processor is set to the THX function. If the processor is configured for non-dipole speakers, the rear surrounds are active when the THX function is chosen, and operate in conjunction with the side surrounds. Indeed, they play about 4 dB louder than the side surrounds at this setting. (In the dipole mode, the side surrounds play considerably louder than they do m the monopole mode, to offset the loss of the rear surrounds.)

In some listening rooms, it is possible that the use of four conventional surrounds in this semi-THX arrangement will result in better simulated theater performance than if a single pair of dipole surrounds are utilized in the usual THX style. Obviously, this will be good news for enthusiasts who are averse to using dipole surround speakers.

Great as all this is, it is possible to get evil better results with the processor's Logic 7 mode. This function, also only available with the THX and Dolby Digital versions of the DC-1, reproduces both musical material and film soundtracks with maximum separation, for an uncanny hall or movie-theater feel. In addition to its remarkable steering up front, Logic 7 deals with the surround information in such a way that a simulation of four discrete surround channels nearly results. (Like Music Surround, it employs a rear-delay offset to better acoustically separate the side surrounds from the rear surrounds.) With standard 2-channel, matrixed, Dolby Surround program material, the result is a remarkable three-dimensional hall/theater effect to the sides and rear that comes close to mimicking what one hears with 5.1-channel Dolby Digital and DTS soundtracks.

I should note here that in order to make the Logic 7, Music Surround, Music Logic, and the DSP-simulation modes work to best effect, it is necessary to follow the previously noted guidelines about positioning the side and rear-surround speakers. In my particular room, this would be impossible to do without rotating my entire interior 90 degrees, so that I would be facing the room's shorter wall. This arrangement would allow me to have the listening chair far enough from the rear wall to come up with the desired angle between the side and rear surrounds.

I temporarily did some serious speaker and, furniture shifting to accomplish this feat, and can say unequivocally that the results equaled, and in some cases surpassed, anything I had been able to achieve with my old setup. Unfortunately, the position of my laboriously installed, ceiling-mounted projector and pull-down screen, not to mention assorted doors and windows in the room, make it impossible for me to permanently utilize this kind of arrangement without doing a whole lot of architectural manipulations, but it was fun while it lasted.

Finally, the DC-1 is ready and able to deal with the latest, 5.1-channel, Dolby Digital and DTS soundtracks in a very capable manner. In addition to the usual, straight DD and DTS decoding (both of which work better than typical, simply because four surround speakers are employed, rather than the usual two), the processor offers a variety of THX 5.1, 5.1 Music, 5.1 Logic 7, DTS Film, DTS Music, and DTS Logic 7 modes that, by utilizing the smart-surround steering the processor offers, can sometimes make these two exciting movie and music formats sound even better. This is done by a combination of matrix steering and time delays, which helps to eliminate the comb-filtering that can result from using multiple surround speakers in a parallel hookup. Much of this will depend on the speaker layout and room acoustics, of course, but it is great that the processor allows the user to adjust the sound-field to such an extent.

Note that DTS has not standardized on the LFE level, meaning that for DTS music CDs you would probably do best to listen in the DTS Music mode, which automatically attenuates the LFE level by the required 10 dB. However, note also that the Logic 7 surround-channel matrix decoding, which can fill out the surround channels possibly a bit better than the straight-surround signals, does not work in this mode. You do get the decoding with DTS Logic 7, but, as noted, the LFE level is not correctly attenuated in that mode, which would make many DTS CD recordings sound bass heavy.

Consequently, for the best performance with some DTS music CDs, you might at least try DTS Logic 7, while temporarily attenuating the LFE level by 10 dB. (This is a pain in the neck, in my opinion, but blame DTS, not Lexicon.) I should note that the degree of Logic 7 matrixing applied in any of the 5.1channel formats is slight, So many listeners will be more than satisfied with DTS Music, which still has the basic stereo surrounds. The non-standardized behavior of DTS program material may account for some of the mixed comments the format has been receiving.

I submitted this processor to a number of recordings during the few months that I had it. These included two-channel stereo and Dolby-matrix-encoded test and demo programs from the Delos Surround Spectacular set, The Digital Domain (Elektra 60303), and Stereophile Test Disc 3 (STPH 006). I also auditioned basic stereo musical recordings such as Peter Warlock's Capriol Suite (Delos DE 3132), Shostakovich's Symphony Number 8 (Delos 3204), John Rutter's Requiem (Reference Recordings RR-57CD), Mozart's Quartet Number 22 (Delos DE 3192), Billy Dean Fire In the Dark (Liberty 98947), King of Instruments (Delos DE 3503), the John Basile Quartet's The Desmond Project (Chesky JD 156), and K.T. Oslin's Love In A Small Town (RCA 2365). In addition, I checked out two binaural releases from Newport Classics: Strauss's Also Sprach Zarathustra and Saint-Saens' Symphony Number 3 (10001), plus Stravinsky's Le Sacre Du Printemps and Rachmanininoff's Symphonic Dances (10002). Finally, I also listened to and viewed a number of Dolby Digital music videos and DTS-coded compact-disc releases. These included the Dolby Digital transcriptions of the Tchaikovsky 1812 Overture, from the Delos DVD Spectacular release (DV7001), as well as a large number of DD and DTS releases, some of which you will find reviewed in this issue's Scoping Software column.

While I am sure that many of our readers are mostly interested in the musical performance of the DC-1, I should at least briefly note that I also tried a variety of laserdisc and DVD movie programs, in both standard Dolby Surround, Dolby Digital, and DTS formats. These included The Rock, Stargate, Diehard 3, The English Patient, Blown Away, Daylight, Gettysburg, The Fifth Element, Evita, Jurassic Park, Goldeneye, Terminator 2, Aliens (both standard Dolby Surround and DD versions), Crimson Tide, and Dante's Peak. In each case, I felt that the advantages of 5.1 audio were readily apparent, although the Logic 7 function of the DC-1 had the uncanny ability to often simulate 5.1 audio with standard Dolby Surround program material.

I should also note here that the differences between the DD and DTS movie program material I encountered appeared to mainly involve main and surround-channel equalization, in addition to somewhat higher surround levels with DTS. In no case would I be willing to say that the differences were attributable to the different coding schemes. Mastering philosophies overwhelmed the digital differences. Both formats sounded terrific.

Anyway, I can state without equivocation that the Lexicon DC-1 is the finest surround-sound device I have ever tested. A number of other units can match it in terms of Dolby Digital and DTS performance, and with certain kinds of hall-ambience simulations. However, if it is set up in a proper listening room, none can surpass it when it comes to dealing with the extraction of ambience from Dolby, matrix-encoded software, and none can even approach it when it comes to simulating a well-imaged soundstage with two-channel program material.

It is an expensive sucker, but if your listening room can accommodate its speaker-layout requirements, and if you can also afford the necessary outboard amplification (and outboard AC-3 demodulator if you want to listen to Dolby Digital laserdiscs), and you have a real interest in simulating a live-music environment in a home-listening situation, or you want the best in home theater, you would be crazy not to purchase the DC-1. -- HF