New Digital, One.

This column, or serial article, has some ambitious goals in mind, the first of which is to try and dispel some doubts and technical confusions which have grown both in the minds of part of the enthusiasts, and in the specialised press, traditional or web-based, regarding the new consumer formats for digital audio. Other goals and background ideas will be clear as the column proceeds. The column won't be, for the time being, a regular one, as the instalments, after this first background and clarification (trying to clarify both my and, hopefully, your ideas) parts, will be tied to the development of the high resolution software and hardware market. In this first instalment I will explain my perspective and I will briefly describe the two contenders for the high-resolution digital audio market; in the second instalment I will try to outline a brief history of the why and when we got to the current situation; in the third one I will talk about what can win or lose the battle for one or both formats - and I still think both can lose -, i.e. software availability; the fourth one will be the most technical one, as it will be an attempt at a technical description of the formats. This is the temporary plan, which can of course be modified by the events or by your feedback. After this planned phase, the column will be driven by the market situation - it's possible that, in a few months and after the announcements coming from the CES and around (namely, The Dark Side of The Moon and a significant part of Dylan's discography for SACD, the announcement of hybrid DVD-A/CDs and the decision of Classic Records in favour of DVD-A, new multi-format and non multi-format players) - the situation will be more readable, and by your interest.

Background

This column, the name of this site notwithstanding, is written by a two-channel (not multi-channel) kind of audiophile, who is also convinced that video interferes, at least a little bit, with the enjoyment of reproduced music, mostly of music played in real environments by acoustic instruments, and excepting musical theatre. I have been often more disturbed than helped by video while enjoying a classical music concert reproduction, disoriented by the necessary use of editing/cinematography techniques - which I still think are necessary, lest the director wants to incur in that "Fidel Castro speech" effect, a couple of fixed camera hours can have the best of the most dedicated spectator - which I think is the opposite of a realistic reproduction attempt, and this latter is what we all (heretics and Sakuma fans excepted) try to get, within the limits allowed by economical and technical conditions. A close up on brass while the sound perspective remains the same (and I surely don't ask for the sonic soundstage to be changed accordingly) vaguely, but still unpleasantly, upsets my involvement. I still have to explain why two channels. I want to make it clear, that this isn't a radical position - I don't think you'll find any in this "magazine". It's a temporary, conditions-determined choice, forced by real estate considerations, which I think are common between European apartment dwellers. My sensation is that multi-channel, the real, opulent one, made of n+1 dot m channels, was designed with larger surfaces than ours in mind, and that it requires dedicated, non shared, listening spaces. I have only recently seen space-saving quality solutions, such as the Gallos our Francesco Pampanoni has reviewed in our Zero issue, able to be installed in a layman room without causing a family crisis or an aesthetic mess. Furthermore, this classic two-channel choice allows for a fair, neutral field comparison between the new standards and the old champions, purely based on subjective performance. As our editor is wont to say, "first of all, listen in two-channels mode".

A brief survey on the contenders

If there's a war, it's because there are at least two contenders on a battleground (yeah, "Monsieur de la Palisse, Stephen sneered, was alive fifteen minutes before his death", sorry James J.). According to my plan as outlined above, this survey, while trying to be technically sound, isn't meant to be complete in any way: I will try to publish a more complete one in due course, what I need now are the basic facts, just to establish what we're talking about. The two contenders, I was saying, and every audiophile knows them, at least by name: on one side, SACD, on the other one, DVD-A. Common to both is the fact that the player which is required in order to take advantage of the high-resolution content can read normal CDs also; in DVD-A's case, the players also have the ability to read DVD-Video discs. SACD is the new standard proposed by the developers and owners of the most important patents for the CD format, Sony and Philips. Maybe because of this fact, SACD has had, from the start, the option of "hybrid" discs, compatible with old CD players, by the use of a technical trick which renders the high-resolution layer invisible and transparent to standard CD players, whose pick-up is only able to see the normal CD layer. However, this feature is only an option; time-to-market and technical difficulties in tuning the hybrid production lines have forced Sony and Philips to downgrade this feature to an option, and Sony Music is the label which is publishing most of their SACDs on non-hybrid, so called "single layer", discs. Speaking about the high resolution layer, SACD implements a coding and sampling standard (DSD) which is conceptually different from any other consumer format, including the "old" CD. A single bit sampling is used (CD uses 16 bits) at a very high sample frequency (2.8 MHz, CD uses 44.1 kHz). Technical details will be discussed in the planned dedicated instalment of this column; for the time being, I think that it's only needed to know that the bit rate (the output data stream) is grossly on a par with that of a 96 kHz/ 24 bit sampling on the same number of channels, and that SACD advantages are the fact that DSD D/A converters are much simpler than those used in DVD-A and CD, the fact that no digital filter is required - only noise shaping is - and the fact that DSD's distortion is in direct proportion with the intensity of the reproduced sound, as it is for vinyl (not in reverse proportion, as in CD and DVD, which are based on PCM coding). Multi-channel is part of the standard from the first published specification (the fact that, for a year or so from SACD's inception, discs and players have been stereo only was determined again by time-to-market considerations); it's a discrete multi-channel - compressed encoding standards such as Dolby Digital or DTS are not used - and, to squeeze the data into a disc, a proprietary lossless (such as the ZIP most PC users are familiar with) compression algorithm, named DST, is used. The multi-channel program is an option, as are pictures - I don't know about any disc on the market containing pictures -; the only required program for a disc to comply with the SACD standard is the two channel, high resolution one. Content protection is implemented by a physical watermark on the disc, which has not been cracked until today. As a further content protection system, no consumer recording deck is planned. It's less easy to talk about DVD-A in a coherent and simple way, considering the options and sub-options of the standard and its still ongoing evolution. DVD-A was meant to be the high resolution audio evolution of DVD-Video, which has almost completely replaced the VHS cassette from its market leading position in the video software market. But DVD-A has been delayed from the start by lengthy discussions on the features to be included and by still partially unsolved content protection issues. The proposing consortium includes a large number of companies, ranging from information technology hardware manufacturers to record labels. The system provides for a higher (about two times) bit rate than that of DVD-Video and SACD; this feature is used to store on the disc high resolution programs, which range from discrete six channel, 96 kHz/24 bit to two channel, 192 kHz/24 bit resolution; to comply with the bit rate and with program length considerations, a proprietary lossless compression system (MLP, Meridian Lossless Packing) is used. It is possible to include, in the same record, a Dolby Digital or DTS encoded track, or a 96 kHz/24 bit stereo uncompressed track, to allow the disc to be played by DVD-Video players, and to encode video or still picture content. The linear (i.e., discrete) multi-channel program can include hints that can be used by a DVD-A player to down-mix to two channels on the fly - in other words, a two channel track isn't compulsory, contrary to SACD, but players can extract an optimised, producer specified one from the multi-channel content if a hard coded two channel mix isn't included. As a content protection measure, an optional watermark can be included, allowing to track the origin of unauthorised copies; the content provider also has the option to inhibit high resolution data to be passed on by the players' digital outputs, downsampling them to (little more than) CD quality. One of DVD-A main current problems is the fact that it's not easy to tell what's inside a record case in terms of resolution and included mixes; to correct this, some software providers, such as DTS (with their record label hat on), are proposing standard labelling which try to inform the consumer about what he is buying. The fact that the format is not frozen yet can be inferred also by the recent announcement that hybrid DVD-A/CD discs will be produced; conceptually similar to the SACD hybrids, these discs will be "sandwiches" (one side of the disc will be a DVD-A, the other side will be a standard CD).

See you soon for the next instalment.