Part I: All About The Making of a DVD-Audio Disc 
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Written by Mark Waldrep, Ph.D.   
Friday, 01 October 2004

AV Education on RHT

Part I: All About The Making of a DVD-Audio Disc

Written by Mark Waldrep, Ph.D.

Readers of online publications like Audio Video Revolution often read reviews and comments regarding new releases on both SACD and DVD-Audio, the new multi-channel, high-resolution audio formats. There’s always the obligatory listing of tracks and a discussion of the sonic quality of each title and a breakdown of the features included on each disc, but rarely do consumers get details on the production procedures and challenges that go into producing a title in these new formats. It might be nice to know the recording process involved (analog vs. digital stages), the number of mixing choices made during a production and the depth of bonus materials that will be included on a disc. Well, as the producer of many DVD-Audio titles for my own audiophile label, AIX Records, and owner of a production facility that services the DVD production needs of other labels (Rhino, Sanctuary and Savoy Jazz, for example), I thought it might be interesting to explain and discuss the production realities behind a few DVD-Audio titles. The plan is to break down the process into three distinct phases: the pre-production planning, the actual recording, mixing and mastering, and the multimedia development/DVD authoring. This process is also relevant to other new technologies like DualDisc as well as music oriented Blu-Ray or HD-DVD discs but please note none of those formats are currently on store shelves quite yet.

In the interest of complete disclosure and fairness, I should state right out front that my personal preference in the “format war between SACD and DVD-Audio” skews in favor of high-resolution PCM over DSD. Let me share a few of my reasons for this choice. First and foremost is the fidelity of the sound delivered to our customers. While both formats have the potential to deliver audio fidelity that surpasses CDs, comments that I regularly receive from customers and the reviews that I read put our tracks at or near the top of most lists (we recently took Number One and Two in the list of the Top 20 “best multi-channel discs” in the May/June issue of DVD Etc. Magazine). Secondly, AIX Records has been producing multi-channel, high-resolution digital audio for many years and has developed a rather extensive capability for dealing with multi-track PCM audio. All other things being equal, the number of equivalent tools in the world of DSD is not yet as great. In fact, a large percentage of so-called DSD tracks actually existed at some point in their life as PCM. When I started making our products, the best available DSD system, the Sonoma from Sony, could record only eight tracks and all post processing had to be done in the analog domain, so going with PCM was a no-brainer. Thirdly, as any current AIX Records customer will attest, I am a strong advocate of delivering feature-rich discs to consumers. This means having video, photos, lyrics and much more on the same disc that plays the new high-resolution, multi-channel audio. As most of you are already aware, DVD-Audio discs usually contain a “DVD-Video” zone. Producers of DVD-Audio titles can choose to place Dolby Digital or DTS mixes in that portion of the disc for playability in DVD-Video machines, as well as video footage. SACDs are audio-only products; there is no provision for multimedia. The final reason why I chose to release titles in the DVD-Audio format instead of SACD is the vast number of players that can access the audio and video that we put on each disc. Currently, there are over 75 million DVD-Video players and 3.5 million DVD-Audio players (including factory installed car systems), compared to more than a million SACD players reportedly installed in the U.S. Don’t get me wrong, SACD can sound very good, especially for stereo music, but as a professional recording engineer and the owner of a specialty record label, I prefer to make and sell DVD-Audio titles.

I founded AIX Records in the spring of 2001 because I wanted to explore the emerging DVD-Audio format with music content that I would produce and own. Back in the spring of 1997, AIX Media Group was the first company to produce and commercially release a DVD-Video title. Yes, we had 100 percent of the DVD business for five days back in March of that year. Since then, we’ve produced many hundreds of DVDs for movie studios large and small and have maintained a healthy production company in the intervening years. The arrival of the DVD-Audio format offered an opportunity to produce AND own content. Since the cost of making an audio title pales in comparison to producing a feature film, since we have tremendous expertise in audio/music and since I’m an audio engineer/musician, the world of DVD-Audio seemed the right place to start a new venture.

Planning a DVD-Audio Title: Audio Considerations
The DVD-Audio specification provides a great deal of flexibility to both artists and producers. With flexibility comes choices that need to be made prior to the actual production: recording, mixing, mastering, graphic design and authoring. For a moment, let’s forget about any of the non-musical elements and deal with the choices in the audio arena. As with the DVD-Video specification, the use of Dolby Digital or PCM is common, with DTS often included as an optional format. The number of channels depends on the type of production and the available space on the disc. A typical DVD-Audio disc includes a 5.1 channel Dolby Digital surround mix and a two-channel “stereo” PCM track, both of which can be played on a standard DVD-Video machine – the PCM stereo can even be at 96 kHz/24-bits! These tracks would be placed in the DVD-Video “zone” for complete compatibility with the millions of home theaters in the country. The real benefit of using the DVD-Audio format is its “advanced resolution” capability. By omitting the movie MPEG-2 stream, a 5.1 channel surround mix at 96 kHz/24-bits can be included. At this resolution, it is necessary to use a lossless type of data compression to keep the required data bandwidth within DVD transfer rates. Advanced Resolution DVD-Audio streams are therefore encoded using Meridian Lossless Packing, or MLP. Alternatively, producers can choose to use 48 kHz/24-bits avoiding MLP or even mix and match the sample rates to keep within the bandwidth boundaries, although I’m not aware of a single product or authoring tool that includes this capability.
The options for audio encoding discussed above are employed at the tail end of the production process. Nobody is actually recording their tracks using DTS, Dolby Digital or MLP; these are simply the schemes used on the delivered discs. The other part of the pre-production process involves the particular production path that the audio will undergo on its way to the disc. Remember the days when CDs first appeared and the RIAA designed a coding system to indicate whether a disc was recorded, mixed and mastered in the analog or digital domain? Consumers could read the AAD or DDD designation and have some sense of the production path that was used on the album. Sadly, purchasers of both SACDs and DVD-Audio titles aren’t privy to the type of recording equipment and processing that the audio undergoes prior to encoding. Basically, there are only three choices.

The first and most common way to encode a disc is to identify and locate an archival analog tape and recast it as a “high-resolution” DVD-Audio or SACD. Ideally, the right multi-track master and accompanying documentation can be found and then used by the original engineer/producer/artist to create a proper 5.1 mix. Unfortunately, this doesn’t happen very often. The master tapes may be difficult to find, poorly documented and the original participants unavailable. The big companies have done a pretty good job of producing new mixes of these catalog albums by hiring experienced engineers and involving the artists in the process. The fidelity of the original analog master, however, is never eclipsed when starting from existing tapes. Consumers do get the sound of the studio master, an experience that they’ve never had at home before, but ultimately the quality of the sound is established at the time the musicians sit in front of the microphones.

The second option is to take tracks that have been recently recorded in a low-resolution digital format, for example 48 kHz/24-bits or even 16-bits, and upsample them to a higher sampling rate. There are some very expensive processors that do this sort of work, but the results are rather vaporous and unconvincing. With the arrival of Pro Tools and other digital workstation environments, this method has become common as well. Believe it or not, my production studio has actually taken a manufactured CD and created a 5.1 channel, “advanced resolution” 96 kHz/24-bit audio master for another label to release on the DVD-Audio format. Seems a bit misleading to me, but take a listen and you be the judge.

Finally, there’s the approach that I decided to take with our productions. Start from scratch. Since my label is a completely new company, we don’t have an archive to dip into in order to make DVD-Audio titles, nor do I endorse the limitations on fidelity that come from starting in the analog or low-resolution domain. My opinion is that in order to launch an exciting new format, you have to fully exploit the benefits of that format. In the case of DVD-Audio and high-resolution audio, it seems obvious that making new recordings with live musicians is the most reasonable choice when producing new titles. After all, the music exists in the air only at the time of the recording, not from an analog capture of it using technology that in some cases is 30 years old. It makes a difference.

In part two, we’ll talk about the planning of the bonus features that can accompany a disc. In the meantime, if you have never heard a DVD-Audio disc, try ordering one from Amazon and play it back in your DVD player. Even DVD-Video players can get you some exciting audio results. Other than my own discs, I like The Beach Boys’ Pet Sounds, Vince Gill’s High Lonesome Sound, America’s Homecoming, and REM’s Best of disc. There are over 750 amazing titles out there on most major and many smaller labels. Hopefully, you will get as hooked on this new audio format as I have.

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