DOLBY DIGITAL vs.DIGITAL SURROUND/THEATER SOUND
by Howard Ferstler

Many people believe that Dolby Digital, even at 448 kbps, is not able to deliver the musically truthful goods. And while 1509 and 754 kbps DTS is ahead of DD in terms of its data rate and lionized by some people for its home-theater abilities, even that technology is said to be musically inferior to what we have available with DVD-A. However, I believe that either of these two technologies can deliver the musical accuracy, with room to spare.

Indeed, most of the significant differences I have heard between the DVD-A, Dolby Digital, and DTS tracks on a number of DVD-A music releases I have auditioned for review in the magazine The Sensible Sound appear to not be the result of digital anomalies. Rather, they appear to be the result of mastering and mixing decisions. Notwithstanding the well-documented, sub-audible differences between these technologies, I came to this conclusion for two reasons.

The first involved the way the discs sounded during A/B listening comparisons where I had two copies of each. This allowed me to simultaneously audition them on DVD-A and regular DVD players that were connected to the same audio system. During these sessions, I felt that I could sometimes hear differences in surround ambiance and center focus above the bass range. However, the contrasts were so slight that I wrote them off as happening because of my inability to get perfect level matching accomplished during switchovers. During subsequent listening comparisons I continued to sometimes hear differences, but the source of those differences continued to be nettling.

My second conclusion involved the way the different versions measured when I employed peak-level-hold techniques with my AudioControl SA-3051 real-time analyzer. I did see some broad-bandwidth response-curve differences with some (but by no means all) program material. However, there is just no way that digital-coding differences could be responsible for artifacts of that magnitude or distribution.

In a number of my record reviews I have indicated that even when the DD and DTS tracks paralleled the DVD-A tracks with my peak-level readings, they were generally higher in average level than the DVD-A tracks. I assumed that the reason for this involved the way the Yamaha DSP-A1 processor/amp I was using at that time in my main system, in combination with the two players I used for comparing work, dealt with those very different kinds of inputs and outputs. I also noted that the DSP-A1 has bass management with its six-channel analog inputs (it is one of only a handful of processors that has this ability even now), thereby leveling the playing field during any kind of comparison with the digital inputs. Or so I thought.

Another artifact I mentioned involved the seemingly more powerful bass with the DD and DTS material. This was a mystery, because there should be no problem in that area at all. Digital differences notwithstanding, all three formats should be pancake flat into the low-bass range. However, I have belatedly discovered something relating to DVD-A bass performance with the combination of equipment I was using that I should have been aware of early on.

If one accesses the audio set-up menu on the player I use for DVD-A (an Onkyo DV-S939), they will discover that once they select the 6-channel-output mode, there will be the option of fine-tuning what has been chosen. While the player’s bass-management options will only work with DD and DTS outputs, the individual, channel-level adjustments will work with ALL the outputs, including DVD-A. The default setting is “zero” for all of them, and the only adjustment options involve the ability to cut the levels on each of the six. They cannot be boosted.

After a bit of experimentation, I discovered that if I backed off the five satellite level adjustments by -10 dB each and left the subwoofer adjustment at the zero-default setting, the relative bass balance with DVD-A program material would achieve parity with that of the DD and DTS source material. It would do this via both the digital outputs and the analog outputs. This characteristic may exist with any number of other DVD-A capable players.

Unfortunately, even with the satellite/subwoofer levels properly matched and the DSP-A1 applying proper bass management to all channels, I still managed to hear subtle differences between some DVD-A tracks and their DD and DTS counterparts. The artifacts were only apparent with quick-switch A/B comparisons, and would not ordinarily be evident with everyday listening. At times they were so slight that I was not sure if I was hearing differences or just imaging them. The reason for these subtle differences is pretty clear once you think about it, because the DSP-A1 does not have the ability to electrically compensate for different distances between the listener and the assorted satellite speakers with the six-channel analog inputs. It can do the compensating in the digital domain with the DD and DTS inputs, and even with two-channel analog inputs given treatment with DSP ambiance synthesis. However, it cannot do them with those particular analog inputs. You have to set those specific channel delays with the internal functions of the player itself.

Now, while DVD-A players that have on-board DD (and possibly DTS) decoders can apply the appropriate delays to the various satellite channels with the DD (and DTS) outputs, most, including the Onkyo player, cannot do it with the DVD-A outputs. The Yamaha/Onkyo combination was doing fine with DVD-A material in terms of bass management and satellite/subwoofer level balancing. However, with that same DVD-A material, no compensating time delays for different speaker distances to the listener were being applied. On the other hand, it was being applied with DD and DTS sources.

Since I could not apply compensation delays with DVD-A at all, I temporarily zeroed out all the delays that the Yamaha was applying to the DD and DTS tracks. I then did a series of new comparisons, and the results were usually a subjectively perfect match between DD, DTS, and DVD-A. Unfortunately, not dialing in those delays meant that distance compensations were then improper with all of those playback modes.

So, have to conclude that the supposed differences some people have been hearing between DVD-A and DD/DTS releases of the same material, involve the maddeningly difficult task of getting (1) bass management, (2) satellite levels, and (3) channel delays all matched up. While it is easy to get things right with DD and DTS, it may be impossible to get them all proper with DVD-A in most rooms and with most speakers and processors.

And that, ladies and gentlemen, does not speak well for DVD-A, and shows how idiotic it was to not allow the DVD-A data stream to be automatically output in digital form, with a decoder installed in the outboard processor or receiver. Since I have not as yet had a chance to play with SACD, I have no idea if the problem exists with that format, nor can I be sure that every DVD-A receiver/player combination will also have it. But some obviously do.

OK, we just finished dealing with some bad news. Is there any good news?

There most certainly is. As I have noted above, it definitely appears that the DD and DTS tracks on DVD-A releases, as well as what we have with regular old DD and DTS music videos, have the potential to sound as subjectively refined as what we get with DVD-A. What’s more, a lot of the time they may actually sound better than DVD-A.

One reason involves the distance-delay issue. However, another reason involves simple channel-count numbers. If your surround processor is a 6.1 job with a “center-back” channel, you may be able to put that feature to good use for even better surround envelopment, particularly with certain pop-music presentations. This is something that cannot be done with the DVD-A feed. This is a wonderful thing, because it allows owners of standard DVD “video” players who have not yet sprung for a DVD-A player to get just about all the sonic thrills 5.1-channel surround music can offer

Up ahead, you will find four DD reviews and one DTS review. I believe that in terms of sound quality these transcriptions will hold their own against any of the better DVD-A releases that I have reviewed so far. In addition, they sound considerably better than quite a few other DVD-A transcriptions, some of which are technical dogs. All of these recordings, bad and good, are that way for reasons that have little or even nothing to do with digital technology.

The previously released, compact-disc versions of the material on the first three DVD items reviewed were originally encoded with Delos Records’ own VR2 brand of standard Dolby Surround. Those CDs sounded excellent on conventional, two-channel stereo systems. In addition, they could also be decoded with any Dolby Pro Logic or Pro Logic II decoder. With that processing they could deliver left, center, and right channels, with the center derived from the L+R part of the mix, plus a surround channel extracted from the 180-degree-out material coded on the left and right channels.

With earlier Pro Logic decoding, the extracted surround signal would still be in mono form, just like with Dolby Surround movies. This definitely worked against simulating a proper sense of larger-room space. However, with Pro Logic II decoding (particularly the “music” mode), the sense of hall space was considerably enhanced, and with a proper center-width adjustment (DPL II has that feature) the result could be much better than simple two-channel playback. Still, the big question is whether the processor-manipulated CD sounds as good as the DVD version?

The fourth item reviewed is a DVD music video featuring James Taylor. There is nothing esoteric about it other than a soundfield that is almost uniquely excellent. The review will explain why. The last item is a review of an Eagles concert that is also a music video. However, it is presented in DTS sound, and like the other items reviewed here it demonstrates that superior sound is now available to just about anyone with a DVD player and a DD/DTS decoder.

The speakers used during most of these reviews are situated in my main listening room. It is roughly 22 x 18 x 8.5 feet, giving a displacement of about 3,400 cubic feet. The main speakers are 12 feet apart and are located against one of the 22-foot walls, and the listening position is roughly 14 feet from that wall. There are also two other systems in the house, with each located in a room of roughly 2000 cubic feet. Most of my record reviewing for The Sensible Sound is done is done on the main system, but some is also done on the other two, particularly with certain smaller-scale programs.

Here is a list of the audio hardware currently in the main room:

Allison IC-20 (two, used as the main speakers).
Custom-made speaker, using eight Allison drivers (center speaker).
Allison Model Four speakers (four, used as surrounds).
Allison/RDL AV-1 speakers (two, used as back surrounds).
Velodyne F1800RII subwoofer (main subwoofer)
Hsu TN1220HO subwoofer (center-channel subwoofer).
Onkyo DV-S939 DVD-A player.
Sony DVD-S360 DVD video player.
Pioneer DVL-700 LD/DVD/CD combi player.
Yamaha RX-Z1 receiver.
Dbx 3BX dynamic-range expander (rarely used these days)
AudioControl Phase Coupled Activator bass synthesizer (also rarely used).
Rane THX-22 1/3-octave equalizer (for the two IC-20 speakers).
AudioControl C-131 1/3-octave equalizer (for the center speaker).
Hsu 250-watt power amp for the center subwoofer.
Carver M500, 250-wpc power amp for the main speakers.

The RX-Z1 receiver is set up so that its two, on-board, main 130-watt amps drive each panel of the center speaker, and its main-out signals are routed to the Carver M500. The receiver powers all of the surround speakers, and the total power available to all speakers is in excess of 2,000 watts. The receiver is a recent addition, and prior to it the system was centered about a Yamaha DSP-A1 processor/amp. The latter has been moved to my smaller system, replacing a DSP-A3090, which was then moved to my living-room system. Unlike the DSP-A1, the RX-Z1 does not have bass management with the 5.1 analog inputs.

The IC-20 speaker systems have ten drivers apiece (four tweeters, four midranges, and two woofers), with each group of four mids and tweets mounted vertically, MTTM style, on the top halves of 45-degree sideward angled panels. The woofers are at the bottom of each panel. One advantage of the woofer locations with the IC-20 systems is that mid-bass suckout artifacts are minimized, due to their acoustic relationship with the floor/wall boundary. IC-20 is capable of flat response to about 30 Hz if no subwoofer is involved. This is important when reviewing DVD-A releases on this system.

The custom center also has four tweeters and four midrange/midbass drivers, but no big woofers like the IC-20s. (The Hsu subwoofer takes care of center-channel bass.) The center speaker resembles an IC-20 sitting on a short stand.

The four Model Four systems each have two tweeters on 45-degree sideward angled panels, plus an upward-facing 8-inch woofer. They are located on the side walls, roughly 6.5 feet from the floor, with the front pair about three feet in from the front wall and the other pair about 10 degrees back from directly to the sides of the prime listening couch. The Model Four is capable of providing flat bass to about 45 Hz, although their bass feeds are normally routed to the main subwoofer.

The two AV-1 back-surround speakers each have a single tweeter and single woofer, and those are the same kinds that are in the center-front speaker. The back surrounds are four feet apart and roughly 7.5 feet from the floor. The system also has a Sharp LCD video projector ceiling mounted and aimed at a 4 x 8 foot screen that pulls down from above and latches to the back of the center speaker.

Here is a list of the audio hardware currently in the second-system’s room:

NHT M6 speakers (two, used as the main systems).
NHT VS1.2 (center speaker).
Radio Shack minispeakers (four, used as surrounds).
SVS 16-46PC subwoofer (non-standard driver installed).
RCA DVD player (about to be replaced).
Toshiba VCR.
Panasonic VCR.
Pioneer DLP 503 LD/CD combi player.
Yamaha DSP-A1 integrated amplifier.
Dbx 120 subharmonic synthesizer (rarely used).
Hsu Optimizer low-bass equalizer.
AudioControl Ten Series III equalizer (about to be replaced).
Mitsubishi 45-inch rear-projection TV monitor.

Here is a list of the audio hardware currently in the living room system:

NHT ST4 speakers (main systems).
NHT SC1 speaker (center channel).
NHT SB3 speakers (two surround speakers).
Hsu VTF-3 subwoofer.
Panasonic DVD-A120 player.
Panasonic VCR.
Yamaha DSP-A3090 integrated amplifier.
Sony 32-inch direct-view TV.

I have reviewed quite a few of the listed audio products for The Sensible Sound and have  additional speakers and subwoofers in storage for use as reference systems when reviewing products that are similar in configuration and similar in price. Those include a pair of Dunlavy Cantatas, a pair of AR Phantom 8.3s, an SVS 25-31PCi subwoofer, and a Hsu VTF-2 subwoofer.

 

THE RECORDINGS

Delos DVD Spectacular.

Produced in 1997 (with musical excerpts recorded in 1996), this disc was the first in this series of DVD-music releases by Delos. Basically, it is a compendium of musical numbers and test sequences (there are no moving pictures with the musical sequences, or even stills, but the test sequences do have visual aids), done with the cooperation of Dolby Laboratories. The musical Engineering was done by John Eargle. The DVD production team was made up of John Eargle, Jeff Mee, and Ramiro Belgardt, with the assistance of Roger Dressler, at Dolby Laboratories. Delos DV 7001.

Right off, I should note here that all of the test sequences on this release are identical to some of the more straightforward and easier-to-use ones on the DVD demo/test disc that Dolby Labs has produced for professional use. However, one advantage this Delos release has over the Dolby item is that it comes with a passably decent instruction manual that explains, in everyday rather than engineering, terms, what some of the audio and video test sequences are, and what to listen for. Indeed, it was not until I got this disc that I learned how to interpret a couple of the tests on the Dolby Digital test disc I also have for home-theater set up. The test sequences are not in the same class as what is offered by the Avia test disc available from Ovation Software (the Avia disc is in a class by itself when it comes to workable tests for DVD enthusiasts), but it will do in a pinch. I should note that the disc can be purchased directly at the Ovation web site at http://www.ovationsw.com/

Some of the more basic and useful tests on the Delos release include assorted frequency-response sweeps, a 5-channel/Pro Logic auto-switch-testing sequence, and a very helpful polarity test, which can be used to determine delay adjustments for the surround and center speakers. There are also some basic video-test patterns, designed to check for interference between DVD audio and video signals.

One interesting thing I should point out involves the low frequency effects (LFE), or .1 channel. On this disc, it is employed with all of the Dolby Digital (AC-3) test sequences. However, it is not used with any of the musical material, including Tchaikovsky's 1812 Overture, which is the disc’s main musical feature. When I first got my copy, I was thunderstruck by the very concept of those cannons being downloaded into my system from the LFE channel. When I discovered that the LFE channel was not used, I was both curious and temporarily demoralized.

However, in series of phone discussions and letters, recording engineer John Eargle has pointed out to me that the requirement for a LFE channel comes from the 70-mm, mag-strip days of theater, when the five main channels were generally modulated to the hilt, leaving no room for special effects. Customary practice in Hollywood was to reduce the signal level going to the effects track by 10 dB and then boosting it back 10 db during playback. This practice has been carried over into the 5.1-channel specifications for digital film system in the theater, and by extension, into home theater via the AC-3 and DVD standards.

Indeed, the subwoofer channel is perhaps more workable in the home-theater context than in theaters, because so many home-theater rigs make use of small satellites and subwoofers. Because all home-theater systems with Dolby Digital capabilities can configure their processors to sum the low-frequency content of the five main channels for the subwoofer feed (indeed, this is probably the best way to configure any system even if the satellites are fairly large), there is really no need to use the LFE channel in music-only applications. As a matter of fact, transferring musical bass signals to the LFE channel may be counterproductive, because they will not have been recorded onto a separate bass track during the recording session. Rather, they would have to be filtered and sent to it during the post-production work, thereby opening up opportunities for numerous integration-related problems to develop.

In addition to the 448 kbps Dolby Digital recording of the Tchaikovsky 1812 Overture, as performed by the Dallas Symphony Orchestra and Chorus, this release has a recording of Carol Rosenberger playing the Piano Barcarolle, by Richard Rodney Bennet. The disc also has the 1812 in its Grammy nominated PCM digital form, which will allow the user to compare the two-channel version with the discrete-channel Dolby Digital version.

After experiencing the musical selections on this disc, I can say without blushing that as far as I am concerned, Dolby Digital is fully capable of handling even fairly complex musical material with aplomb. The imaging was precise when listening from on or off axis, the clarity was exemplary, and the surround effects were all one could desire. Because the original version of this material did not employ a “hard” center microphone pickup, the center channel on this disc is a simple, somewhat subdued L+R blend. However, with program source material of this kind soundstaging deficiencies are minimal.

The 1812, as performed here makes use of a chorus, and during the performance their singing initially comes from the rear and sides of the hall, an effect that I found to be both somewhat gimmicky but also impressive. How realistic it will sound on a given system will depend upon how one’s speakers are set up. I also found that the center-rear-channel feature available on receivers like the Yamaha RX-Z1 can work fairly well if, again, the speakers are set up properly and the center-rear level is properly calibrated.

On the 1812, the hall ambiance appeared to be a bit more reverberant than what I am used to, and I backed off all of the surround levels a tad to get what I feel was a better sense of realistic hall space. However, I have never been in Meyerson Center, so I cannot say for sure what the acoustics are really like. If the purpose of having a strong degree of surround ambiance was to get attention of the listener, it certainly did the job.

The cannon shots on the 1812 did not have quite the wallop of the now classic Telarc compact disc version of 1812 (Telarc 80041), nor did they have the impact of a newer Telarc DVD-A release featuring the Cincinnati Pops Orchestra (Telarc DVDA 70541). However, John Eargle has informed me that the pyrotechnics (including the bells) were done in house, during the live performance, and not electronically overlaid later on. Hence, what you get is live-music realism and not electronically manipulated pyrotechnics. Hey, this is a music recording and not a movie, remember. Still, I did miss the punch of real cannons.

 

Delos DVD Music Breakthrough.

This five-channel, DVD-music release was originally produced in 1998. The performances involve a number of ensembles, including the Dallas Symphony, the Oregon Symphony, and the New Jersey Symphony, and the music includes excerpts from and complete works by composers as divergent as Korngold, Berlioz, Mussorgsky, Gershwin, and Kern. Engineer: John Eargle. 93+ minutes. Delos DV-7002.

Unlike some early DVD-music experiments (most of which were music videos), you can easily play this disc with your TV set turned off, at least on the five different players I tried. All that is required is for the user to put it into the drawer, hit the "close" button, wait a few seconds for it to cue up, and then hit "play." If you do turn on your TV monitor, you will see that the first two motions get you to an on-screen menu that default to the "play program" setting. On many previous DVD-music releases, you absolutely had to turn on your TV set to listen to the music, or at least to get it going, because specific, visually controlled menu commands were required. Not so, here, at least with my players. I should also note that this disc does not have any moving pictures. It is primarily a music disc, with some still images and not much else to look at.

Overall, this release is one of the best classical-music audio transcriptions available. While the center channel is "derived" from what appears to be a simple, non-steered, L+R mix, it is very well controlled and usually fairly subdued. More importantly in this case, the surround ambiance and the left-right spread go well beyond anything you would hear with a conventional recording played on a two-channel system.

A surprising number of 5.1 recordings, particularly reissues from two-channel originals, still employ a L+R, "derived" center channel like this one, or even a phantom center. This is because the master tapes we have on hand were mostly created with two-channel playback, or at least two-channel compatibility, in mind. However, as engineers begin to record for discrete 5-channel playback, and nothing else, I believe we will begin to experience extremely well-defined, independent center channels that will be able to greatly enhance soundstaging for individuals sitting both on and off axis. Engineers have worked for decades to perfect two-channel stereo, and it will take some of them time to creatively employ a discrete center channel to harden up the center. However, as techniques improve, soundstaging will become dramatically better than anything we have ever experienced during the two-channel era.

I compared some of the excerpts and selections on this release to the full-length, compact-disc versions I also happened to have on hand. These included The Sea Hawk release (Delos 3234), as well as the Berlioz Te Deum CD (Delos 3200). When played back with DPL decoding, the CD version of the Berlioz work was one of the best Dolby-matrix-encoded transcriptions I have ever heard, particularly when given the Dolby Pro Logic II decoding that is available with the RX-Z1. In addition, it was also one of the best sounding discs I have ever experienced when played back in straight, two-channel-stereo form. However, the excerpt transcribed to the Dolby Digital, DVD version we have here still has the edge. For example, while the CD I reviewed had wonderful ambiance with basic DPL II decoding, it could not generate discrete images out in the hall. The DVD version can do that handily, which resulted at times in a better sense of space. This was quite an accomplishment, given the exemplary character of the Dolby matrixed CD version.

I will note that top-quality surround processors, particularly ones like the Lexicon DC and MC series or the Yamaha units that are in my three systems, can do a pretty remarkable job of synthesizing hall ambiance from two-channel program sources by means of their assorted DSP modes. However, this DVD release did manage to do something that the two- channel CD release simply could not pull off, even with the most sophisticated DSP assistance from a top-grade processor. It allowed the organ part of the program to actually come from the rear of the listening room for really dramatic effect. Thus, during the initial part of the excerpt from the Te Deum, the organ and the orchestra actually answer back and forth from the front of the hall to the rear.

While reviewing this disc later on, I had a chance to again use the center-back channel offered by the Yamaha RX-Z1 that I recently installed in my main system. With that channel engaged, the centered-up organ sounds were somewhat better defined and more to the rear than with basic two-surround decoding. How well this comes across will depend upon the taste of the listener, the way the speakers are set up, and the shape and size of the listening room

 

Delos DVD Space Spectacular.

This 5-channel release contains complete performances of Also Sprach Zarathustra by Richard Strauss, and The Planets by Gustav Holst. The performances are by the Dallas Symphony Orchestra conducted by Andrew Litton. It was recorded in 1997, at McDermott Hall, Meyerson Center, Dallas. The engineer was John Eargle. 85+ minutes. Delos DV-7003.

Unlike DVD Music Breakthrough reviewed above, this release does require you to use your TV set, at least if you want to easily access the Holst material.

With the Strauss, all you have to do after initially hitting the drawer-close button on your DVD player (which closes the drawer and accesses the main menu) is wait a few moments for the TOC to appear and then hit "play." If you do this, Zarathustra will begin. However, getting to Holst is a bit more involved, and the job requires on-screen menu work. While my two smaller systems have manageable TV monitors that allow for this kind of menu hopping, my main system has the previously noted front projector and pull-down screen. I am loathe to use it just to listen to a music disc containing still pictures, and so I have an auxiliary 5-inch set that I use for accessing menus. Even those with big rear projectors or big direct-view sets might consider a second, smaller monitor for menu accessing musical program sources. Saves wear and tear on the big set. Radio Shack has pint-sized sets that will do just fine for under $100. Just remember that they must have monitor inputs to handle DVD video.

There is a helpful diagram on the back of the booklet that comes with this disc. However, although it shows you the menus and how to get on and off most of them, it leaves out the critical step required to jump past Strauss and get to Holst. Indeed, even if you use your TV monitor, it will take you a few seconds to figure out the ropes once you have accessed the chapter contents. They have only the Strauss material listed, and to get to the Holst program you have to key on the arrow on the right side at the bottom of the menu. Once you get there, hitting "play" will get you The Planets. After you get the hang of it, this operation could be done without a TV set being turned on, as long as you remember the keystrokes. Although this release is easier to work with than the first Delos DVD music release, DVD Spectacular (which absolutely required that the TV be turned on to get to the required programs), it is not as intuitive to work with as the Breakthrough disc.

Carping out of the way, I can get on with more important things and state here and now that technically this is the best recording of both the Holst and Strauss material I have heard. It displays sound quality that is equal to, or possibly even better than, many of the pieces on the above-reviewed Breakthrough disc. The presentation is borderline astounding, with very good detail, stupendous dynamics, and absolutely no Dolby Digital "artifacts" that I could detect.

As with the two other Delos releases, this DVD has no LFE channel. Consequently, if you have your subwoofer set up so that it only handles the low-frequency effects with movie material, you may lose substantial bass impact, unless your main speakers are very potent bass producers all by themselves. For best results with both this and other Dolby Digital DVD material (even movie releases that include an LFE channel), set your processor so that ALL the bass, and not just that from the LFE channel, goes to your sub.

 

James Taylor Live at the Beacon Theatre.

Recorded in May, 1998. DVD audio engineering by Frank Filipetti and John Alberts. Length: 109 minutes. Columbia Music Video (Sony) 50171.

Yes, this is the DVD music video some of you may be have already heard about and hopefully also heard. It is as good as some critics say, and it does two things very well. First, it delivers a fine performance, with exemplary sound. Second, it shows that Dolby Digital at 448 kbps is capable of all the fidelity that anyone needs, data reduction notwithstanding. Until you listen to this disc (well, watch it, because you need to at least access the video to operate it with some players), you just do not realize what is musically in store for us in the new, 5-channel age.

I tried it with all three of my systems, and one of the more notable things is the surprisingly deep bass on some tracks. Most of the time this is pretty subtle, but if you have a serious subwoofer you will most certainly hear it. Another notable thing is the use of a truly discrete center channel. This is not some kind of L+R blend but instead is a true center feed that is capable of delivering all the advantages of a discrete center. Some will dispute the advantages of a “hard” center, but there are good reasons why it can work extremely well with material that features a centered soloist.

With a “phantom” center, such as we have with conventional stereo, the listener receives four arrival clues. That is, each ear hears each speaker, with the ears further from each of them getting a somewhat delayed signal. On the other hand, with a genuine centered performer or genuine center channel the listener receives only two arrival clues. Each ear hears only the sound coming directly from the center. While the half-left and half-right images will still be phantoms, there is no doubt that centered-up soloists will be more realistically reproduced by a genuine center channel than by a phantom feed.

Of course, there are qualifications with any system, and two of those here involve the quality of the center speaker and its location. If it is inferior to the left/right mains the center sound may not be all that good. And even if the center speaker is a good one, if it is located at a radically different height from the left/right mains (say on top of a big TV monitor) the soundstage will simply not be realistic.

This problem with center-speaker quality and center-speaker location may be one reason why some recording engineers still prefer to not fool with a center channel. They realize that the all-important center information may be severely compromised during playback on some systems. Of course, some engineers simply do not like the center channel even when the speakers are high in quality and optimally positioned. Old habits die slow deaths, sometimes.

In any case, on this disc the center feed is exemplary and we can thank outstanding engineering for the results.

 

A Fine DTS Release.

The Eagles: Hell Freezes Over. DVD music video. Originally recorded in 1994, with DTS remastering ca. 1998. On-site engineering by Elliot Scheiner. 99 minutes. Geffen 5479.

An interesting thing about this release is that it first appeared as a compact disc (Geffen 24725), although the CD is shorter than the DVD. (The latter has an extra track that was not on the CD version.) Another interesting thing is that I happen to also have that CD version, and so I was in a position to do an experimental series of quick-switch comparisons between it and the DVD video.

Doing a rapid-comparison with the PCM two-channel tracks and the 5-channel tracks on the same disc would be impossible, because to switch from track to track you have to access the disc menu and make the switchover the slow way. Doing it with a separate compact disc was made even easier thanks to the RX-Z1’s quick-switch input feature, which allowed me to rapidly switch from the DVD to the CD, and simultaneously switch from basic DVD playback to any number of DSP ambiance enhancements with the CD version.

I should also re-emphasize that this is a DTS music video DVD, and not a DTS CD. Consequently, in order to access the above-noted menu you actually need more than a DVD player. You also need a TV monitor hooked up to your audio system. Without a monitor, you are up the creek if you want to get this disc rolling properly no matter what kind of audio hardware you might happen to have.

When you first cue up this disc you will find that the beginning tracks deal with the details of the reunion and do not have any music at all. You can skip through these sections if you want, and a few tracks into the production things get rolling along quite nicely. I should also indicate here that the compact-disc version has more printed information in its accompanying booklet than what was available printed on the DVD version’s container. The various tracks on the CD are also in a different order from those on the DVD, which I found odd.

Initially, I was struck by the soundstaging refinement, clarity, and detail delivered by this transcription. The audience sounds come mainly from the surround channels and there is some nice hall reverb out there, too - putting the listener into a live-music environment. Besides audience noises, there is also some instrumentation placed in those surround channels.

Now, I have to admit that I do not ordinarily favor performer/instrument sounds happening in the surround channels, if only because it does not simulate a live-performance situation. (An exception would be Berlioz, who in his Requiem has brass bands in the corners of the hall). However, in some situations it is at least interesting and attention getting. Because rock music is kind of fabricated to begin with (with many recordings I would imagine that the recording engineers are probably more talented than the performers), the effect will certainly be enjoyed by some listeners. In any case, the surround instrumentation on this release was not overdone, and so I can live with it.

As I noted above, one interesting thing I did was to cue up that two-channel CD that I have and compare it to the DTS version. In straight stereo there really is no comparison. The CD has no discrete center, of course (although the DTS version does not have a particularly strong center feed, either, and the disc could almost be classed as a borderline 4.1-channel mix, at least on some tracks), and it also has no surround channel. However, oddly enough, the bass line of the CD sounded considerably more potent than what I heard with the DTS version. The CD was sometimes maybe a bit too bass potent, as a matter of fact.

The RX-Z1 has a bass-management menu for DTS (as well as for Dolby Digital, of course) and you can access that and either attenuate or boost the DTS low-frequency effects channel by up to 10 dB. (You can only attenuate the LFE with Dolby Digital, with zero as the normal setting.) After a bit of diddling, I ended up boosting the DTS LFE level the full 10 dB available. When I did so the bass was quite well balanced and it actually was cleaner, sometimes deeper, and often more realistic sounding than the bass on the CD. The reason for the needed boost has to do with the different set-up standards for DTS movie and music releases. Elliot Scheiner has informed me that this was his first 5.1 recording and he was concerned about the use of the subwoofer channel. Apparently, he was also talked into using a pair of not-perfect subwoofers that made his mixing work even more difficult. In any case, the real problem was the DTS movie/music settings and not the mixing job, per se.

After listening to the compact disc version in straight stereo, I then engaged some of the RX-Z1’s surround-synthesis functions to see if I could make the quality of Scheiner’s two-channel CD approach that of his 5.1 channel DTS version. I had the best luck with the Yamaha’s “Classical/Opera” mode, which combines Dolby-like steering up front with DSP ambiance synthesis in all four of the surround channels that this processor offers. To get that mode to work to best effect with the CD, I had to attenuate the center level by -3 dB. Otherwise, the disc’s sound-stage spread was compromised by the Dolby-type steering.

I find that this 3-dB-cut technique is a good idea when using the Yamaha Classical/Opera mode to deal with nearly any two-channel-music program material. However, I also tried the processor’s Dolby Pro Logic II (music) mode with the CD, and that was also aesthetically a technical match for the DTS version, without needing to back off the center level. DPL II actually had a better sense of center focus than the DVD version, due to the excellent steering involved. DPL II also allows for some adjustments that help to refine the soundstaging to a remarkable degree.

The results with both the Classical/Opera and DPL II (music) modes were excellent, and except for audience noises and instrumentation not showing up in the surround channels, the CD sounded pretty much as good as the DVD with that kind of diddling applied. Note that I did not say the same. I said “as good.” I think that the DTS version would have had a distinct edge if it had exhibited a somewhat better focused center channel. However, as I noted, this was not the case with this disc.

 

Summary.

As I have noted, these are not the only DVD music discs I have reviewed. I have had a chance to audition maybe five dozen multi-channel discs of all kinds, with perhaps half of them being DVD-A. Some were new recordings that sounded sensational. Some were reissues that sounded sensational. Some were new or reissued releases that sounded pretty bad. However, with all of them, the DD and DTS tracks were easily as workable as the DVD-A tracks. And in many cases the duplicate-performance, two-channel PCM compact-disc versions I also have on hand were able to sound as good as the 5.1 (or 4.1, or 4.0) versions. Sometimes they sounded even better, provided they were given sensible DSP ambiance processing.

However, the reasons they sounded better had nothing to do with the digital technologies involved. Rather, they involved the recording techniques and the way those techniques interacted with my listening rooms and surround processors. The three important things I have learned while fooling with these new technologies are:

Multi-channel recordings of any kind (even if they are DSP synthesized from two-channel compact discs) easily have the ability to sound better than what we get with two-channel-only playback.

Data-reduced recordings do have the ability to capture enough recorded music and ambiance to deliver high-quality subjective realism.

Even DVD-A releases can sound pretty bad if the engineer does not know what he is doing, or if the material is taken from original two-channel mixes that exhibit what would be considered "dated" sound by today's standards.

H.F. (September 2002) (for a bio of Howard Ferstler, click HERE)