New age audio: more DVD-A technical observations. (Skeptimania).

In several of my record-review columns, I have mentioned that most, if not all, of the significant differences I have heard between the DVD-A, Dolby Digital, and DTS tracks on a number of DVD-A music releases were probably the result of mastering and mixing decisions on the part of the engineers and technicians doing the final-project work. 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 a release. This allowed me to simultaneously audition them on DVD-A and regular DVD players that were hooked 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, but 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.

The second involved the way the different versions measured when I employed peak-level-hold techniques with my AudioControl SA-3051 RTA. I did see some broad-bandwidth response-curve differences with some (but by no means all) program material, but there is no way that digital coding could be responsible for those kinds of artifacts.

In a number of reviews, I mentioned 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 felt that the reason for this probably involved the way my Yamaha DSP-A1 processor/amp (reviewed by me in issue 72), in combination with the Onkyo DV-S939 player (reviewed by me in issue 86) and Sony DVD-S360 player (discussed by me in issue 84's "Skeptimania" column) 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, 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 presented itself as 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. Along these lines, 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 you access the Onkyo player's audio setup menu, you will discover that once you 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 your only adjustment options involve the ability to cut the levels on each of the six. They cannot be boosted.

After diddling around, I discovered that if I backed off the five satellite adjustments by--10 dB each, but 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 output via both the digital outputs and the analog outputs.

In other words, in order to get the six-channel, analog outputs of the Onkyo, be they DD, DTS, or DVD-A, to achieve proper acoustic balance, compared to what I got with the DD and DTS digital outputs, I had to have the subwoofer output a full ten dB louder than the individual satellite outputs. I have no idea if this is an artifact of the player or a characteristic of a DVD-A technology whose parameters were not fully set at the time the player was designed.

In any case, if you have an Onkyo DV-S939 player, or any other DVD-A player for that matter, it might pay to experiment with the individual channel level adjustments with those six-channel outputs it uses for DVD-A.

Unfortunately, even with the satellite/ subwoofer levels properly matched and the Yamaha applying proper bass management to all channels, I still managed to hear subtle (often maddeningly subtle) differences between some DVD-A tracks and their DD and DTS counterparts. The artifacts were only apparent with A/B comparisons, and simply would not be evident with ordinary listening.

Then, one recent evening, while doing a bit less drinking and a bit more experimentation than usual, I discovered that when using its six-channel analog inputs, the DSP-A1, even though it has bass management and the ability to control global and individual-channel levels, does not have the ability to electrically compensate for different distances between the listener and the assorted satellite speakers with those analog inputs. It can do this 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 the six-channel 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 onboard 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 I reviewed, 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.

So, my conclusion about the supposed differences people have been hearing between DVD-A and DD/DTS releases of the same material, involves 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.

New Age Audio: Software News--OK, we just finished dealing with some bad news. How about some good news?

Well, 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 good as DVD-A, and that most of the time, due to hardware-related contingencies, they are in a position to sound better.

After all, if your surround processor is a 6.1 job with a "center-back" channel, you may be able to put that to good use for even better surround envelopment (particularly with certain pop-music presentations), something that cannot be done with the DVD-A feed. And of course, as I have noted, the DD and DTS tracks are not plagued by any kind of bass-management and delay/distance setting limitations. The technical problems with DVD-A discs involve the DVD-A tracks and not the DD and DTS tracks.

This is a great thing, because it allows owners of standard DVD players who have not yet sprung for a DVD-A player to get just about all the sonic thrills 5.1-channel surround can offer. In addition, the tracks containing the DD or DTS material will often have considerably more in the way of extra features, such as full-motion video, documentaries, etc. Heck, let's be realistic: in most situations they can forget about getting a DVD-A player altogether.

Anyway, I recently obtained three ambitious and interesting software packages from American Gramaphone, the company that produces the Mannheim Steamroller recordings. (For all intents and purposes, American Gramaphone "is" the Mannheim Steamroller.) Normally, I would review all such material in my "Scoping Software" column, but I will make an exception here with one of them--Fresh Air 8--because of how interesting it happens to be. The other two discs, Ambiance: Summer Song and Christmas Extraordinaire, although partaking of much of the technology and features found with Fresh Aire 8, will be reviewed later on in my "Scoping Software" columns.

These are two-disc sets, with the discs stacked one above the other on a spindle that is deep enough to hold both. One is an HDCD mastered compact disc, done in the usual two channel-form. As best I can tell, each of the CD releases is also available as a separate item for those who only own CD players.

Each box also contains a DVD that has a DVD-A program on one side and a DD/DTS program on the other. It makes sense to use both sides, in contrast to most other DVD-A releases that have everything on the same side, in dual-layer form. With the latter, if you put the disc into a DVD-A player it may not be able to access the DD/DTS tracks at all, at least in 5.1-channel form. It may default to DVD-A, and stick to that mode. You may not even be able to pull up the DD/DTS menu. With two sides being used, you can play the DD/DTS side in a DVD-A player and access all the standard video functions.

The DVD-A material, except for the menu and a few video stills, are free of embellishments. It is a true audio-oriented presentation, and Fresh Aire 8 (which, taking all of its double-disc materials into consideration, contains more than four hours of program material) is one of the first DVD-A discs I have encountered that works nearly as smoothly as a compact disc, at least for the 5.1-channel outputs. You just put it in your DVD-A player, hit "play" a time or two, and off you go, with even the track readouts and timings working just fine. If you have a speaker/room and processor arrangement that can deal with DVD-A properly, this can be a wonderful, no-television-set, audio experience.

However, the DD and DTS side of the Fresh Air 8 disc is considerably more ambitious than the DVD-A side, going well beyond what one would typically encounter on a music disc of any kind. The same audio program is included, although the DD/DTS side has some dramatic full-motion video embellishments that might prove distracting to some.

I did a series of peak-level readouts between the DD and DVD-A material, and the two curves pretty much paralleled each other. They also sounded similar in quality (if I zeroed out the processor delays with the DD/DTS tracks, so that they matched what was happening with the DVD-A tracks), although I did not have multiple copies of them with which to do rapid A/B comparisons. For safety's sake, let's just say that the DD and DTS programs did not give up anything audibly significant to the DVD-A programs.

Well, to be truthful, if one wanted to just turn the TV off and listen to the music on the DVD video side, the dramatic embellishments on some of the tracks would tend to get in the way, I think. The beginning musical track and part of the final musical track are interlaced with video-dialog material that sounds out of place if you do not turn on the TV monitor. There is nothing like this on the DVD-A side, which is music only. However, some of the music-video material is captivating, if only because of the stunning looking women in the Greek-philosophy tracks. Trust me on this.

Digressing a moment to talk a bit about sound quality, Fresh Aire 8 has to be a must for any enthusiast who wants not only clean sound from his program material but who also enjoy crystal-clear treble and an impressive bass line. The bottom extension, in particular, was clean and deep (sometimes really deep and powerful, particularly on the "Big Bang" track), and even though this is electronic music (admittedly, the London Symphony Orchestra is dominating on certain tracks), I can recommend the material in any of its digital iterations as fit for auditioning speaker systems, including the most serious of subwoofers.

Even the placement of instruments in the surround channels worked just fine in this case, although for me doing that sort of thing with standard classical and acoustic-instrument music remains unsettling. With Fresh Aire 8 (as with a number of pop-music 5.1 releases now available) the disc itself is an art form, rather than a way to simulate a live performance. Obviously, recording techniques have become polarized into two different creative forms, and this appears to not be a bad thing at all.

Getting back to the offerings on the DD/ DTS side, the presentation has much more than the music-video material. First, it has a series of additional, full-motion video dramatizations that highlight the philosophical concept of "infinity" that is the theme of Fresh Aire 8. Much elaborate work went into putting these snippets together, and the disc also has a segment that shows how the work was done. Gaffes include, however, dramatizations showing assorted, non-contemporaneous Greek thinkers debating each other. For example, Aristotle did not party with Thales, because 200 years separated them.

Another feature allows one to access a series of brief lectures by assorted academics outlining the historical, mathematical, artistic, philosophical, physical, and religious underpinnings of the concept of infinity. Although the commentaries are shorter than one might like, and will not enthrall experts in those fields with new and complex revelations, there are some interesting tidbits. For audio buffs, there is also a discussion of the high-end nature of the Fresh Air series by Chip Davis, the composer/producer/engineer who started it all over two decades ago. Davis also expounds on many of the philosophical themes the disc presents, and also discusses the way some of the video material was done.

Overall, the two-disc Fresh Air 8 package, which lists for $25, is the first digital-audio offering I have encountered that begins to exploit the full musical and educational nature of what the new technology offers. That the music it contains is superbly recorded, quite diverse in style, and often wonderfully entertaining is only partially why I recommend this material for audio/video freaks.

-HF