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DTS-ES Discrete 6.1 The Ultimate Backward Compatible Surround Format
By Shane Buettner
Preface
On June 15, 2000, Digital Theater Systems or DTS® formally introduced the DTS-ES Discrete 6.1 format. Soundtracks encoded in this format are 100 percent backward compatible with all current 5.1-channel DTS decoders as well as current Surround EX and DTS-ES compatible matrix decoders. In other words, in addition to a 5.1-channel bitstream, a matrix-encoded back surround channel also will be present on these soundtracks, which can be decoded by the current crop of matrix decoders on the market that are being used in conjunction with current Surround EX-encoded soundtracks. Obsolescence of current equipment is not an issue with respect to the introduction of this new format.
DTS also introduced DTS' Neo:6, a matrix-decoding algorithm that derives up to six channels of audio from any two-channel source; and DTS-ES Matrix 6.1, a DTS solution for decoding 5.1-channel soundtracks with a back surround channel matrix encoded into the left and right surround channels (i.e., Dolby® Digital Surround EX™). Both of these matrix-decoding algorithms are based on the algorithm used in DTS' theatrical DTS-ES Extended Surround adapter.
At the same press conference, Denon Electronics introduced the world's first component to carry the DTS-ES Extended Surround suite of features, the new flagship AVR-5800 receiver. This powerful new receiver is powered by Analog Devices' Melody DTS-ES decoder, which is implemented on a 32-bit floating point SHARC DSP engine. This device boasts a processing speed of 50MIPS (millions of instructions per second) and a computational power of 80 MFLOPS (millions of floating point operations per second.) The AVR-5800 uses two of these powerful DSPs to perform its dazzling array of processing and post-processing functions.
In addition, the first software products offered in DTS-ES Discrete 6.1 were revealed to be DreamWorks' DVD Signature Collection of The Haunting, tentatively scheduled for August, 2000, Don Henley's End Of The Innocence, which was released on June 30, 2000 as a DTS CD features the title track (only) mixed and presented in discrete 6.1, and Studio Voodoo's self-titled DTS CD which will be mixed and presented in discrete 6.1 and is scheduled to be released on August 15, 2000.
DTS-ES Logo
At WSR we've been following these developments closely, and with this article we intend to offer an overview of DTS-ES Extended Surround, including details on the new DTS-ES Discrete 6.1 format. WSR was invited to sit in on the mastering session for The Haunting, so we'll give you an idea of how a discrete 6.1 soundtrack is created. We will offer Q&A interviews with those involved in the introduction to this format at DTS and Denon Electronics. Further, we were able to obtain a pre-production sample of the Denon AVR-5800 and will share our observations of this new format first-hand, using the DTS-ES Discrete 6.1 DVD of The Haunting as well as two music tracks from the aforementioned DTS CD releases by Don Henley and Studio Voodoo.
The Past And Present
The Dolby Digital Surround EX format was co-developed by Dolby Laboratories and Lucasfilm THX® and made its theatrical debut with the release of Star Wars: Episode I&emdash;The Phantom Menace in May, 1999. Seven-time Academy Award® winner Gary Rydstrom is regarded as the driving force at Lucasfilm for developing this format which has expanded the surround sound experience to incorporate a third surround channel&emdash;the back surround channel&emdash;into the theatrical environment. With a Surround EX soundtrack the back surround channel is matrix encoded into the left and right surround channels of a 5.1-channel soundtrack and is matrix decoded much in the same fashion that the center channel was matrix decoded by the Dolby ProLogic® algorithm from the Dolby Surround® soundtracks of old. This matrix decoding can be performed by Dolby's own SA10 Surround EX adapter, or one of the other compatible matrix decoders on the market such as SMART Devices' CS-EX or Panastereo's SP23 Surround Adapter. The important thing to keep in mind here is that, while the original stems of these soundtracks are discrete 6.1, the soundtrack printmasters are matrix-encoded 5.1 soundtracks.
To date, 15 films have been released in Surround EX, with at least one more slated by the end of 2000. To put this in perspective, the numbers so far add up to 15 films released in 14 months since the introduction of the format. In addition to Star Wars: Episode I&emdash;Phantom Menace past releases include Toy Story 2, The World Is Not Enough and Gladiator. Current releases include summer 2000's X-Men and The Perfect Storm.
DTS responded to the demand for the Surround EX format theatrically with the DTS-ES adapter, a proprietary matrix decoder of their own design. Although the left and right surround channel signals are input in the analog domain, they are digitized and matrix decoding is performed entirely in the digital domain with 24-bit precision and full octave equalization (also in the digital domain.) Currently, 314 theatres are equipped with the DTS-ES adapter.
THX brought Surround EX technology to the home theatre market under the moniker of THX Surround EX™. THX Surround EX is currently available in THX Ultra-Certified products only and employs the same Dolby ProLogic matrix decoding as Dolby's SA-10 adapter. THX Surround EX decoding is performed in the digital domain as a post-processing block, and compliant surround processors must allow individual time delay adjustments and bass management options for the back surround speaker(s).
Surround EX titles have been trickling into the DVD market over the last several months, starting with New Line's Austin Powers: The Spy Who Shagged Me, and followed shortly thereafter by DreamWorks' The Haunting. More recently, Universal's The Bone Collector was released on DVD with Dolby Digital and DTS Digital Surround soundtracks. Being sourced from the same Surround EX-encoded printmaster, The Bone Collector's DTS track carried the matrix-encoded back surround channel and could be played back using a THX Surround EX decoder or any of a number of "compatible" matrix-decoding adapters such as SMART Devices' CS-3X Jr, or ADA's 6.1 processor.
The Future: DTS-ES Discrete 6.1
With a solid and growing list of Surround EX-encoded releases out there, the demand of the creative community in Hollywood for using this new dimension in digital surround sound is clear. DTS has now developed a powerful new tool for the creative community to exploit when creating these soundtracks for home playback: DTS-ES Discrete 6.1. As the name implies this format allows for a discrete back surround channel as opposed to the matrix-encoded back surround channel of conventional Surround EX-encoded soundtracks. The primary advantages of DTS-ES Discrete 6.1 are those which any discrete format enjoys over a matrix-encoded format: precise sound effect positioning and imaging with no bleed of the back surround channel information into the left and right surround channels, and no collapsing of left and right surround information toward the back surround channel.
Before we get into how DTS-ES Discrete 6.1 functions, let's take a look at the other DTS-ES Extended Surround components, DTS-ES Matrix 6.1 and DTS Neo:6.
DTS Neo:6 is a matrix decoder that derives up to six main channels for any two-channel source, analog or digital. Two decoding options for Neo:6 will be offered in compliant decoders. One decoding algorithm will be tailored to surround-encoded material such as movie content while the other is tailored to stereo material that is not matrix encoded, such as traditional two-channel music. On Denon's AVR-5800, for example, the Neo:6 algorithms are appropriately named Neo: Cinema and Neo: Music, respectively.
DTS-ES Matrix 6.1 uses the Neo:6 matrix-decoding algorithm configured for 3-stereo mode for matrix decoding DTS Digital Surround-encoded 5.1-channel soundtracks that offer "extended surround" capability (a matrix-encoded back surround channel) such as The Bone Collector and DreamWorks' upcoming Gladiator on DVD. The matrix decoding is performed in the digital domain as any other post-processing block in compatible decoders.
How DTS-ES Discrete 6.1 Works
Conventional Surround EX soundtracks are mixed initially as discrete 6.1-channel soundtracks. The back surround channel is then matrix encoded into the left and right surround channels to create a 5.1-channel printmaster. The first step to creating a DTS-ES Discrete 6.1-channel soundtrack is to go back to the original 6.1-channel stems and create a discrete 6.1-channel master, a process covered elsewhere in this story with respect to the first DTS-ES Discrete 6.1 DVD title, DreamWorks' The Haunting.
Once the discrete 6.1-channel master is obtained the discrete back surround channel is encoded as extension file data that is attached to the "core" DTS Digital Surround 5.1-channel bitstream. The size of the DTS data frame and the data rates for the DTS-ES Discrete 6.1 soundtracks remain the same as they would for any DTS-encoded track: 1.2 megabits per second (Mbps) for CD/LD, and 1.5Mbps or 754 kilobits per second (kbps) for DVD-Video. The DTS encoder simply adjusts the compression rate of the other channels to accommodate the additional information containing the back surround channel, thereby lowering, to a small degree, the data allocated to the other channels and maintaining the existing data rates.
The DTS-ES Discrete 6.1 bitstream is encoded with a digital flag that alerts a DTS-ES Discrete 6.1 decoder to the presence of the extension data. Decoders can be configured to auto-switch to DTS-ES Discrete 6.1 decoding upon detection of this flag. The flag is essentially invisible to the current crop of DTS 5.1-channel decoders on the market, which "see" and decode only the DTS 5.1-channel core data.
This implementation takes advantage of the design flexibility of the DTS Coherent Acoustics codec, which has been developed to allow modifications and updates to new encoding technology such as discrete 6.1 on the encoder side but was also designed to keep the decoders relatively simple and thus future-proof. This goal is accomplished by putting all of the "intelligence" of the Coherent Acoustics codec on the encoder end, with the decoders merely following instructions embedded in the audio stream. Initially, DTS-ES Discrete 6.1 encoding will be performed by DTS using software-based encoding systems.
As mentioned earlier, existing DTS decoders do not recognize the flag for the extension data containing the discrete back surround channel. Rather, existing decoders will decode the DTS Digital Surround core 5.1 bitstream, which will also contain a matrix-encoded back surround channel to insure backward compatibility with existing Surround EX "compatible" matrix decoders on the market. One surround channel is phase-shifted +45 degrees while the other is phase-shifted &endash;45 degrees to enhance steering precision when active matrix decoding is employed and keep left and right surround information from collapsing to the back surround channel. The back surround channel information is then matrix encoded equally into each of the left and right surround channels at&endash;3dB.
So, what happens to the matrix-encoded back surround channel when the soundtrack is decoded by a DTS-ES Discrete 6.1 decoder? In addition to sending the discrete back surround channel extension data directly to the back surround speaker, the back surround channel is also put back into the left and right surround channels respectively, inverted in polarity at&endash;3dB, effectively subtracting the matrix-encoded back surround channel information from left surround total (Lt) and right surround total (Rt). In addition to providing the discrete back surround channel, a properly decoded DTS-ES Discrete 6.1 soundtrack restores the original left and right surround channels as opposed to a typical matrix-encoded/decoded Surround EX track in which the left and right surround channels are being actively matrix decoded. With the DTS-ES Discrete 6.1 soundtrack the artifacts typical of matrix decoding, namely the bleeding of back surround channel information into the left and right surrounds and the pulling of left and right surround channel information into the back surround channel, are eliminated. Properly decoded DTS-ES Discrete 6.1 soundtracks will offer superior performance not just in the discrete back surround channel but in the left and right surround channels as well.
Where We Go From Here
The DTS-ES Discrete 6.1 format is clearly a triumph for the flexibility of the DTS Coherent Acoustics codec, allowing superior technology moving forward while maintaining 100 percent backward compatibility with current equipment. DTS has clearly pointed the way with this new technology and all that remains to be seen is how the creative community, which has created the demand for this new feature of surround sound, will embrace it.
An interesting element of the introduction of the DTS-ES Discrete 6.1 format is that it's a rare case of a consumer format preceding a theatrical format. The challenge here is that the current theatrical extended surround format requires matrix-encoded 5.1-channel printmasters, not the discrete 6.1-channel masters required for the DTS-ES Discrete 6.1 format. One interesting development to note is that all indications at this time are that digital cinema will provide discrete channels for extended surround applications. It appears now that as digital cinema moves forward so too would discrete extended surround. Another interesting possibility is that DTS may develop discrete extended surround for theatrical use, which would also spur the use of discrete 6.1 masters. DTS' theatrical codec (which is an entirely different codec scheme than the more advanced consumer Coherent Acoustics codec) has always allowed for expansion of channels to eight discrete channels and DTS has already presented special venue eight channel DTS soundtracks.
Beyond that, it will be left up to DVD content providers and studios to go back to the discrete 6.1 elements to create new masters as was done with The Haunting. It will also be interesting to see if any content providers will become interested in offering their previously released Surround EX titles re-mastered in the DTS-ES Discrete 6.1 format. Two titles that immediately come to mind are Universal's The Bone Collector and Columbia TriStar's The Messenger: The Story Of Joan Of Arc. Both of these titles represented an outstanding sonic experience in matrix-encoded/decoded Surround EX and would only benefit from being presented in the DTS-ES Discrete 6.1 format.
Creating A DTS-ES Discrete 6.1 Master: "The Haunting"
A Surround EX soundtrack such as The Haunting is mixed as a discrete 6.1-channel soundtrack initially. From the original 6.1-channel stems the back surround channel is then matrix encoded into the left and right surround channels to create the Surround EX 5.1-channel theatrical printmaster. The creation of a DTS-ES Discrete 6.1 soundtrack requires a 6.1-channel master. To accomplish this, DTS' Director of Post Production Jeff Levison went back to the original 24-bit/44.1kHz 6.1-channel stems for The Haunting. Jeff chose to perform the discrete 6.1 mastering in one of the post-production rooms at Lucasfilm's fabled Skywalker Sound facility in Northern California's Marin County, and was kind enough to invite me to sit in on the session.
Before I get into the story, I'd be cheating if I didn't impart some of the excitement I felt during what was my first trip to "The Ranch." Like everyone who reads Widescreen Review, I absolutely love movies and movie sound. I was definitely on hallowed ground, walking the halls in which so many legendary soundtracks have been created. Well, to say I felt like a kid in a candy store might not be strong enough.
During the post-production process the new master needs to be converted to DVD standard 48kHz. The Neve DFC console used during the monitoring session could have been used at this point to perform the sample rate conversion. But after asking a few questions of Juan Peralta, the technician who was Jeff's console operator during the mastering session, Jeff found that the Neve's sample rate converter would truncate the 24-bit stems to 20-bit. Jeff really wanted to maintain the integrity of the 24-bit stems and decided he would instead maintain the 24-bit depth at 44.1kHz during the 6.1 mastering and would up-sample to 48kHz later in post-production.
All channels of the new master were monitored at 85dB, C-weighted, but the surrounds were input to the console at &endash;3dB to match the levels of the original mix, which had the surrounds monitored at 82dB. While the home theatre standard for soundtracks references an average volume level of &endash;20 dbfs (decibels below full scale,) Skywalker Sound references &endash;24dbfs to gain extra headroom during mixing. Using the Neve console, a hard limiter set at &endash;4dB was employed to reduce the maximum level in all channels and then 4dB of gain was used on the output side to get back to&endash;20dbfs at 85dB.
The stems for The Haunting are interesting in that there are five actual stems: music, effects, dialogue, Foley effects, and another stem dedicated to the children's voices that float through that grand and spooky old house throughout the film. These 6.1-channel stems were originally created on a Tascam MMR8 and had now been archived to DLT (Digital Linear Tape). Each of the five stems was uploaded to its own dedicated hard drive and the new discrete 6.1 master was recorded back to a Tascam MMR8. During this session the input to the MMR8 was monitored on the Neve console while watching and listening to the film one reel at a time, and listening for and fixing any pops and clicks that may have occurred from dropouts in the restore from the DLT, as well as looking for sync problems against the time-coded DigiBeta tape projected on a screen in the post-production room. Fixing a pop or click can be simple in the case that no sound is present on the stem that has a problem by simply muting over the problem spot. Other fixes involve isolating the channel and stem from which the pop or click emanates and essentially recording over it with sound from one of the other stems. For instance, one such artifact was found in the left surround channel of the "effects" stem. Juan simply mixed the right surround of the effects stem over the left surround, making that effect mono for that one ever so small instant of the soundtrack. In this case, the pop occurred during a sound effect that was panning from one surround channel to the other. Jeff and Juan made sure to listen to that tiny piece of the soundtrack several times after the fix to insure that the stereo image between the surrounds remained in tact and effective.
It's very important that the steps above are carried out with great care as the potential definitely exists for those involved to accidentally record over a sound effect or a piece of dialogue while patching in to fix another problem in the manner described above. Jeff and Juan watched and listened to the film once more in its entirety, one reel at a time. This time monitored playback was sourced from the new discrete 6.1 master via the MMR8's output, closely monitoring for any dropouts on the newly recorded master. The goal to leave Skywalker, with a pristine discrete 6.1 master of the highest quality at 24-bit depth, was accomplished.
DTS' Jeff Levison And Skywalker Sound's Juan Peralta Creating A Discrete 6.1 Master For The Haunting
Encoding
So, Jeff has now sent the Tascam MMR8 discrete 6.1-channel master on separate reels down to Southern California for further post-production work and eventual DTS encoding. In the days following the print mastering session at Skywalker, some interesting information came to light. Apparently, when the original theatrical printmaster for The Haunting was created there was some concern about the prodigious amount of deep bass energy present in all (three) surround channels throughout this aggressively mixed film. The filmmakers essentially worried that the movie theatres out there did not have surround channel amplifiers and speakers that could handle the deep bass extension at the high levels and low frequencies that The Haunting's soundtrack demanded. So great was this concern that a special software program was used that acted as a multi-band dynamic bass processor. I'm over-simplifying here, but this software essentially moved bass frequencies that hit very low frequencies at very high volume levels and moved them from the surrounds to the LFE channel to prevent overload and clipping in the surround channels. This step was employed during the creation of the original matrix encoded 5.1-channel Surround EX printmaster, as it was created from the original stems. Jeff decided that since this solution was employed when creating the theatrical printmaster that he needed to take similar action when creating the DTS-ES Discrete 6.1 soundtrack to accurately represent the filmmakers' intent.
In the meantime, the separate reels of The Haunting's soundtrack had been put together and conformed against the video of the film at Pacific Ocean Post in Southern California. The conformed master was then uploaded to a Sonic Solutions workstation by Ric Wilson at Digisonic for sample rate conversion to 48kHz. The left, right, and center channels of the new master were then output directly from the Sonic Solutions workstation into the multichannel digital interface on Jeff's PC. The three surround channels and the LFE were routed first through a BSS Soundweb, configured for digital domain operation, upon which the bass processing software mentioned above was employed in the same fashion that it had been during the creation of the theatrical printmaster to prevent bass overload in the surround channels. This extra effort on Jeff's part insured that the DTS-ES Discrete 6.1 soundtrack is truly as close as it can possibly be to the original theatrical printmaster while also restoring the discrete back surround channel that the film's mixers created.
At this point, the entire discrete 6.1 master was loaded onto Jeff's PC, which is equipped with a software based DTS encoder. A last step required before the final DTS encoding is matrix encoding the back surround channel into the left and right surround channels to insure backward compatibility with existing 5.1 Surround EX "compatible" matrix decoders. The left surround channel was phase-shifted +45 degrees, while the right surround channel was phase-shifted&endash;45 degrees entirely in the digital domain. Digital domain phase shifting allowed Jeff to avoid phase shifting the back surround channel as well, which would be required if the phase shifting were performed in the analog domain. Jeff encoded the back surround channel evenly into the left and right surround channels at -3dB.
The discrete 6.1 master is then encoded as a DTS-ES Discrete 6.1 bitstream file, which was authored onto the upcoming DreamWorks DVD of The Haunting, due for release in August of 2000.
Sneak Peek At the World's First DTS-ES Discrete 6.1 Receiver: Denon's AVR-5800
Following the introduction of the DTS-ES Discrete 6.1 format and Denon's AVR-5800, WSR was able to get a first look at a prototype of this powerful new receiver along with some early production samples of The Haunting and two music tracks mastered in DTS-ES Discrete 6.1.
The THX Ultra-Certified Denon AVR-5800 is so feature-laden that I'm doomed to merely attempting to highlight the most prominent features. The AVR-5800 carries seven channels of on-board amplification, allowing one or two speakers to be deployed to reproduce the back surround channel. Each of these seven channels is rated at a whopping 170 watts per channel into 8 ohms, over the full frequency spectrum of 20Hz-20kHz. The AVR-5800 employs dual Analog Devices' SHARC-based 32-bit floating point DSP processors for DTS-ES Discrete 6.1 decoding as well as Dolby Digital and all other decoding and post processing functionality. Included is THX Surround EX processing as well as DTS-ES Matrix 6.1 for decoding 5.1-channel DTS soundtracks with extended surround capability and DTS Neo:6&emdash;the matrix decoding algorithm that derives up to six channels of sound from two-channel material and operates with analog or digital signals. Digital to analog conversion is supplied by 16 Analog Devices' reference AD-1853 24 bit/192 kHz DACs operating in differential mode to provide two DACs per channel to each of the AVR-5800's eight channels.
The AVR-5800 boasts eight S-video inputs and three sets of component video inputs. There are three coaxial digital inputs, no fewer than six Toslink optical digital inputs, and one Dolby Digital RF digital input for those of you who still have some Dolby Digital LaserDiscs. There are two digital outputs. There is not one, but two sets of 7.1 channel inputs for upgrading to any future formats (Heaven help us) that have yet to be realized or even conceived. There are full 7.1 channel pre-outs for use with outboard amplifiers. The AVR-5800 can also be configured to operate two sets of surround speakers, and that is in addition to its ability to be used with one or two back surround speakers. As if all this weren't enough the AVR-5800 comes with Denon's new AKTIS RC-8000 Programmable LCD Remote Control and Charger Base/RF Relay Station. Didn't I tell you this thing was loaded? I'm sure I'm neglecting a million features here but trust me, if you can think of a desirable feature, Denon's included it in the AVR-5800!
Now, I only had the AVR-5800 for a week. During this time, DreamWorks supplied me with a very early check disc of the DTS-ES Discrete 6.1 DVD of The Haunting. DTS supplied two music tracks mixed in the DTS-ES Discrete 6.1 format: the title track from Don Henley's The End Of The Innocence, which should be in stores by the time you read this, and a cut called "Fire" from Studio Voodoo's self-titled upcoming DTS CD. Both of these tracks will be available on DTS' year 2000 audio demo CD.
Listening was confined mostly to these DTS-ES Discrete 6.1 tracks and the Dolby Digital DVD of The Haunting which was used for comparative purposes in the review of the DTS-ES Discrete 6.1 DVD of The Haunting that appears elsewhere in this issue. I did not have time to thoroughly investigate the DTS Neo:6 algorithm or much of the other functionality of the AVR-5800. This was not intended to be a review of the AVR-5800, but a first look at a prototype receiver and the first DTS-ES Discrete 6.1 software available. I will be conducting a full review of the Denon AVR-5800 when production units become available in August.
That being said, I did use the AVR-5800 as the heart of my system, including as an S-video switcher, for the week it was here and it performed flawlessly on all accounts, with no operational glitches. Sound was clean and dynamic, with solid imaging, especially in the DTS-ES Discrete 6.1 format. I will reserve more comments for a full review, but the bottom line is that the AVR-5800 did everything I asked it to do and appears to be a terrific component.
Below, I will make some observations about how the DTS-ES Discrete 6.1 format sounds compared to matrix-decoded extended surround. The only way to do this properly, especially with The Haunting, was to listen to the same material using both decoding methods. But this still couldn't produce an exactly apples-to-apples comparison. The AVR-5800 prototype did not allow me to switch back-and-forth between DTS-ES Discrete 6.1 decoding and DTS-ES Matrix 6.1 decoding with the DTS-ES Discrete 6.1 material I had on hand; it decoded discrete-flagged material only in discrete. I don't know if this will be the same with production units, but it wouldn't surprise me. Being able to matrix decode Discrete 6.1 soundtracks is something that's of interest only to reviewers like me who are trying to evaluate the new format's performance.
When reading these observations, keep in mind that I did the discrete 6.1 listening with the Denon AVR-5800 while the matrix-decoded playback was through Denon's THX Surround EX-equipped AVR-4800 (review in progress). I won't give away too much about either receiver, given that I want you to read the full reviews in an upcoming WSR issue, but the primary differences between the two receivers revolve around the more muscular and dynamic sound of the AVR-5800. Not that the AVR-4800 lacks dynamic capability, but the AVR-5800 is clearly its superior in that regard. I was interested most in the spatial and imaging-related attributes of the new format's performance, and that is where my comments are aimed.
Another thing is that all of the DTS-ES Discrete 6.1 encoded material I used played back flawlessly as matrix-decoded 5.1 DTS Digital Surround on the Denon AVR-4800 as well as my reference Lexicon MC-1 processor. I used three different brands of DVD players (Panasonic, Pioneer and Sony) that I had on hand with each decoder and the results were uniformly perfect. Backward compatibility wasn't an issue whatsoever.
 DTS-ES Discrete
As mentioned above, my impressions of the DTS-ES Discrete 6.1 version of The Haunting, and how it compares to the previous Dolby Digital Surround EX-encoded DVD, are included elsewhere in this issue. The focus here is how the DTS-ES Discrete 6.1 material listed above, decoded discretely, compares to matrix-decoded playback of the same material.
In the case of The Haunting, the differences between the discrete and matrix-decoded playback are the most apparent. In addition to the back surround channel effects being more prominent and better defined in the soundfield, the left and right surround channels imaged noticeably wider and also seemed to resolve low-level detail in a superior fashion. In Chapter 10, "Creaking Pipes," there is a sound effect that pans from right surround, through the back of the room, and through the left surround into left front. The DTS-ES Discrete 6.1 put this sound effect, as it moved through the left surround into the left front, farther out in between those speaker positions than I've ever heard an effect placed in my room. It sounded as though it literally came from another room in the house. The matrix-decoded playback of this spatial effect is much less dramatic, and did not recreate this effect with the same impact as the discrete.
There is another sound effect in this same scene, where Hugh Crane's ghost makes a sort of breathing sound that's intended to be behind Eleanor, chasing her. With the discrete 6.1 this effect images much wider in the left and right surrounds, and the effect really fills up the entire back of the room, making it a much more convincing holosonic effect than did the matrix-decoded playback. The matrix just didn't place these effects spatially in the back of the room to such a startling degree.
With respect to the back surround channel specifically, the discrete 6.1 also offered improvements. In Chapter 4, "The Red Room," a large door closes behind Eleanor. This effect was more finely resolved and just a bit more "real" sounding than with the matrix-decoded playback. The sense of the room was portrayed just a hair more convincingly. Later in the film, in Chapter 22, as Crane's ghost is sucked toward the doors of purgatory, a vortex swirls throughout the entire soundfield. The rear of my room in this scene was fully energized with the discrete 6.1, creating a finer sensation of ethereal forces pulling Crane back to where he belonged. This entire effect is realized in a more detailed and exciting fashion with the discrete 6.1 rendering superior low-level resolution in the surrounds and especially the rear of the soundfield.
As mentioned elsewhere in this article, I was fortunate enough to listen to the uncompressed 6.1-channel 24-bit/44.1kHz master of The Haunting in one of Skywalker Sound's post-production rooms. This was a jaw-dropping holosonic experience that I'll not soon forget. The improvements offered by the DTS-ES Discrete 6.1 format are not night-and-day differences over the matrix-decoded playback, but are apparent and significant nonetheless. While the matrix-decoded playback of the DTS-ES Discrete 6.1 soundtrack of The Haunting provided a convincing facsimile of the 6.1-channel master, the discrete 6.1 playback was a more faithful reproduction. The DTS-ES Discrete 6.1 track, properly decoded in its discrete glory, is without a doubt the best reproduction of what I heard from the discrete 6.1-channel master. It is superior to matrix-decoded playback of the DTS-ES Discrete 6.1 soundtrack and dramatically superior, in all respects, to the previous Dolby Digital Surround EX-encoded DVD mastered at 16-bit depth.
How About Some Music?
Switching to the music tracks encoded in DTS-ES Discrete 6.1, I'll start by saying that the Don Henley "End Of The Innocence" cut provided a much more subtle 6.1-channel experience than The Haunting or the Studio Voodoo cut. That is not to say that this cut is not very active in the surrounds, because it is. But it's a very tastefully mixed piece that expands the soundfield to a full 360° without being aggressive with panning or steering music into and out of the surrounds. Quite a bit of the piano is firmly anchored to the rear of the room in this piece, but it really stays there, along with some vocals and other primary information. I really can't say that the discrete 6.1 playback offered any substantial improvement over the matrix decoding with this piece. With both decoding methods the mix was conveyed effectively. At times, I thought the piano had a bit more sparkle and a bit more realism with the discrete 6.1 decoding, but this was definitely subtle.
Studio Voodoo's "Fire" was a completely different experience. This world music (to emulate Dr. Evil, "I don't know music genres, OK?") boasts a very wild and aggressive mix, and the discrete 6.1 decoding offered definitive improvement over the matrix-decoded playback. Throughout this cut, percussion and other instruments appear in the surrounds, including back surround, which very effectively energized the rear of the room. In parts of the song, there is a swirling musical effect that I'll call a "warbling" sound, for lack of a better term. This effect images much wider and fills the rear of the room more convincingly with the discrete 6.1 playback. Toward the end of the cut, there is a vocal that moves from right front to the left rear of the room. This voice made a very convincing arc through the room with the discrete 6.1 playback while falling shorter toward the back of the room with the matrix-decoded playback.
A Lasting Impression
Some degree of the improvements noted in favor of the DTS-ES Discrete 6.1 decoding could be attributable to the superiority of the AVR-5800 over its sibling. Improvements in amplification could certainly improve imaging capability and spatiality, and perhaps the DACs in the AVR-5800 offer superior resolution to those in the AVR-4800. While that may be part of the story, I heard enough from the DTS-ES Discrete 6.1 decoding to convince me that the format itself is a real improvement. The differences between the discrete 6.1 and matrix-decoded playback of the DTS-ES Discrete 6.1 material sampled were more significant than the differences between the two receivers, in my opinion. The biggest surprise to me was the noticeable improvement in performance of the left and right surround channels in this format. This is not to underestimate the importance of the discrete back surround channel itself, which is significant. But the left and right surround performance represents an immediate and large spatial improvement as indicated above.
This initial experience reminds me of the other format births I've witnessed over the last several years. Whether it's Dolby Digital on LaserDisc, DTS on LaserDisc, Dolby Digital DVD or DTS DVD, and now the DTS-ES Discrete 6.1 format; the introduction of a new format is always exciting and exasperating. Exciting with the promise of increased performance capability and exasperating waiting for decoder options and software to hit the market in force. This first taste of DTS-ES Discrete 6.1 has definitely left me waiting eagerly for the software and hardware support that will follow.
Denon's David Birch-Jones On The AVR-5800
Denon Electronics' Marketing Manager, David Birch-Jones talks about the Denon AVR-5800, the world's first component to incorporate DTS-ES Discrete 6.1decoding, which is powered by Analog Devices SHARC-based DSP processors. The AVR-5800, the DTS-ES Discrete 6.1 format and Analog Devices' decoding solutions were introduced at a press conference on June 15, 2000.
Shane Buettner, Widescreen Review: Why was it important for Denon to lead the industry with the first DTS-ES Discrete 6.1 capable component?
David Birch-Jones, Denon: We were the first to introduce a processor with Dolby Digital and THX 5.1, and we were the first to introduce a receiver with Dolby Digital/DTS and THX 5.1 (in the AVR-5700), and we were the first to introduce a receiver with THX Surround EX in the AVR-4800, which also features DTS ES compatibility. This adds to Denon's list of home theatre industry firsts.
WSR Buettner: David, could you elaborate on that and give our readers more insight on the genesis of this project and how it came to be that the AVR-5800 and the DTS-ES format were co-introduced at the same time?
Birch-Jones: It was a function of two things: the compatible timetables and the desire on Denon's part to commit the resources of its engineering team to work with DTS to co-develop the system. Around the time we started development of the AVR-5800, DTS' intentions (with the DTS-ES Discrete 6.1 format) revealed themselves and our chief engineer, Mr. Ichikawa, thought that would be interesting, given the synchronicity between their (DTS') roll-out plans and our timetable with the AVR-5800. Mr. Ichikawa and his engineering team worked with the Analog Devices people and triangulated with the DTS folks to implement the algorithms within the dual-SHARC form. This meant customizing and tweaking the code to make sure the new decoding algorithms fit within the processing power of the (Analog Devices) dual-SHARC implementation.
WSR Buettner: What do you say to those consumers who have already invested in the Denon AVR-4800, now that the AVR-5800, with its enhanced capabilities, has been introduced?
Birch-Jones: We believe that the AVR-4800 provides, at its price point, the best balance of surround decoding capability, sound quality and amplification capability, as well as system upgrade capability, with user assignable power amplifiers, 7.1-channel pre-out jacks and 7.1-channel inputs. At $2,000 we don't think there's anything out there that surpasses it. We think the AVR-4800 is a very high-value component, and the AVR-4800's ES-compatible decoding works very well with the new DTS ES 6.1 discrete releases. The thing consumers need to know is that the DTS-ES Discrete 6.1 format is completely backwards compatible with DTS 5.1 decoders. That cannot be stressed enough. It's further evidence of the creative ability of the consumer electronics business to advance the state-of-the-art while, at the same time, protecting the investments of the existing consumers. I believe this case with DTS ES 6.1 Discrete is another stunning achievement of our industry as a whole.
WSR Buettner: David, you mentioned 7.1-channel inputs on the AVR-4800. These inputs are included on the AVR-5700 as well as several other models in your current line. Do you have any plans at this time to develop an outboard DTS-ES Discrete 6.1 adapter processor that could be used with these inputs? Birch-Jones: At this time we do not have any plans to introduce an outboard adapter. WSR Buettner: In parting, what else do you want to tell our readers about the AVR-5800?
Birch-Jones: High-end, big bucks, separate processors eventually will have as good a front-end as the AVR-5800. As a processor and audio-video switching front-end it beats any and all comers at any and all prices. The fact that it comes with seven amplifier channels and a super-cool remote control, that's a nice bonus.
WSR Buettner: Thanks David, we appreciate your time!
DTS' Lorr Kramer On DTS-ES Discrete 6.1
Widescreen Review asks Lorr Kramer, DTS' Director of Special Technical Projects, some questions about DTS' latest technical achievement, the DTS-ES Discrete 6.1 format.
Shane Buettner, Widescreen Review: What was the impetus for developing the DTS-ES Discrete 6.1 format?
Lorr Kramer, DTS: There was an existing format&emdash;extended surround&emdash;being generated by the studios. Our goal is always the best delivery system possible. We asked ourselves if there was a way to deliver these tracks, avoiding the compromises of a matrix, yet preserving compatibility. And that's what we did.
Extended surround was not our idea. Our idea was to do it right.
WSR Buettner: The printmasters used for typical extended surround soundtracks are matrix-encoded 5.1 tracks, while the new DTS format is discrete 6.1-channels. Is DTS working with the creative community to facilitate the creation of discrete 6.1 masters?
Kramer: From a creative perspective, in extended surround the additional channel has been created. The question is, was it archived as discrete? We are definitely encouraging saving that discrete back channel as input to our system.
WSR Buettner: Will digital cinema have an impact on the above?
Kramer: Yes. All the work we know of assumes all channels will be discrete in digital cinema.
WSR Buettner: Are there plans for a theatrical DTS-ES Discrete 6.1 format?
Kramer: Don't forget that we are already delivering eight discrete channels in special-venue film presentations. There's no technical difficulty whatever for the DTS system. But the equipment installed for feature film exhibition would need changing, which is a practical impediment. Therefore, I don't expect DTS discrete 6.1 in feature-film theatres in the immediate future, but we are planning for additional channels, all discrete, further down the road.
WSR Buettner: Have recording professionals in the music industry expressed interest in mixing in the Discrete 6.1 format?
Kramer: Yes. Some have tried it, some are thinking about it, and of course some have never worked in 5.1, much less 6.1. We present it to artists as simply another creative opportunity with the essential advantage of backward compatibility.
WSR Buettner: How does DTS Neo:6 compare to other matrix-decoding algorithms currently on the market, such as Lexicon's Logic 7 or the Fosgate Six-Axis algorithms?
Kramer: A fundamental difference is that the others generate two side channels and two rear channels, which is not a theatrical format, whereas Neo:6 generates the theatrical channel configuration of two surround channels and a back channel. The operational aspects of Neo:6 are proprietary and we will discuss them soon, but not now.
WSR Buettner: Thanks Lorr, for sharing your knowledge of this new format and its application!
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