Bits Are Bits
Dear Gary: I find errors of reasoning and judgment in Issue 43’s coverage of DVD-Audio. In his article, “DVD-Audio—Boon Or Boondoggle?” Richard Hardesty writes: “SACD is the biggest single advance in audio quality that I’ve heard in the last forty years. DVD-Audio, on the other hand, has yet to demonstrate sound quality that is the equal of, let alone better than, the quality available from conventional CDs.” That doesn’t make sense. DVD-Audio discs could, if someone wanted, hold 16-bit/14.1kHz audio found on conventional CDs, so it is unnecessary for DVD-Audio to “demonstrate” that it is the equal of CD. That would be as pointless as requiring a long jumper to demonstrate that he can jump 20 feet after he’s already jumped 25 feet. The extra information available in 24-bit/96kHz cannot, by definition, make sound quality worse. It merely extends the frequency response and dynamic range of the system; it does not introduce colorations. If Mr. Hardesty finds DVD-Audio inferior to CD, that is because of problems upstream or downstream in the chain, not because of the format itself. The problem could be that 24-bit/96kHz A/D converters need to be refined; 16-bit/44.1kHz A/D converters, although that is less likely because those devices have been in mass production for a few years now. To my knowledge, there is to date no piece of music available on both SACD and DVD-Audio. Thus, Mr. Hardesty enthuses about SACD and dams DVD-Audio without ever having heard a legitimate comparison between the two. Hearing a Mariah Carey cut in stereo DSD and a Pat Metheny cut 5.1-channel 24-bit/96kHz, for example, does not allow anyone to make a meaningful comparison between the two formats. No legitimate and conscientious researcher, engineer, or reviewer would make comparative statements about two devices under test without hearing, through both devices, the same program material at the same level over the same reproduction system. Mr. Hardesty talks about how DVD-Audio requires receiver with a six-channel input, and how those are so rare, but then he states that “SACD players can be used with any amplifier or digital controller with stereo analog inputs, but you’ll lose fidelity if your digital controller doesn’t have analog pass-through capability…” How many A/V receivers have full analog pass-through? Only very small number, because that requires analog bass management be added in addition to the existing digital bass management (as Denon has done), or that no bass management is used in the stereo bypass mode. In comparison, almost every A/V receiver now available has a six-channel input, and that feature has been common for about two years. If your receiver has no analog pass-through, you are losing benefit of SACD, because the analog output of the SACD player will be converted to PCM (probably 20-bit/48kHz or lower) for processing inside receiver. And if you are content to limit yourself to two-channel sound as SACD owners do, you can use any DVD-Audio player in stereo mode, listening to 24-bit/192kHz stereo DVD-Audio discs, downmixed 5.1 channel audio (the downmixing facilities in DVD-Audio are extremely sophisticated), or the PCM stereo tracks (at any resolution the producers select) included on many DVD-Audio discs. And of course, Mr. Hardesty neglects to mention that once SACD goes multichannel as promised, it will require the same six-channel input he claims is not found on most receivers. Mr. Hardesty further states that “Matsushita …and Dolby… may be able to convince manufacturers, content providers, and the public of the need for yet another format that obsoletes their current DVD players.” First, the phrase “yet another” implies that a format was previously introduced that obsoleted DVD-Video players. Which format is it? Second, DVD-Audio discs can contain (and all currently do contain) Dolby Digital and/or DTS Tracks for backward-compatibility with existing DVD-Video players. When you play these tracks, you get full multichannel sound, and that is the reason most people will buy this format, not for the 24-bit/96kHz. Third, SACD also requires you to buy a new player, yet that player will likely be much more expensive than a DVD-Audio Player. There can be little doubt that DVD-Audio players will well for $300 street price or lower once Chinese manufacturers like Apex offer one-almost certainly within two years. Can such a quick price drop be confidently predicted for SACD? In Mr. Hardesty’s Pioneer DV-AX10 review, he states that 24-bit/192kHz PCM sounded “softer, not nearly as detailed as the sound from SACDs.” Elsewhere in the review, he states that the DV-AX10 uses a Burr-Brown PCM1704 192-24 D/A converter for each audio channel. The player is not equipped with a DSD D/A converter, and therefore must convert the DSD signal from the SACD discs into 24-bit/192kHz PCM audio, not DSD. He implies that SACD discs sound better than 24-bit/192kHz DVD-Audio discs on this player. I have a hard time believing, though, that a 1-bit/2.8-megahertz digital audio signal, having undergone a complex conversion to 24-bit/192kHz, could, as he implies, offer a significant advantage over signal that originates as 24-bit/192kHz. In fact, it would almost certainly sound worse. It appears that Mr. Hardesty is extremely (and for no good reason that he is able to convey) biased toward SACD and against DVD-Audio. I recommend you find a writer who is unbiased, more technically thorough, and capable of making a logical case. If one is not available, please at least edit Mr. Hardesty’s work so that is rises to the intelligence level of your readers. I don’t own SACD or DVD-Audio, by the way, although I have heard and been impressed by both.
Hank Morrison
Audio Review Editor Richard Hardesty Comments:
This letter raises some interesting questions about the current condition of our society and about the role that magazines play in disseminating information. Why are some people so angry? Is respect for the opinions and personal feelings of other individuals an antiquated relic of the past? Can magazines adequately serve both entry-level and more experienced readers with information that will enlighten the former without boring the latter? We live in a time when respectful disagreement and good manners seem to have gone out of fashion. It is currently fashionable for individuals with lots of pent up hostility to vent their aggressions without restraint. The victim may be a worker in a service industry, a magazine writer or any other individual who is perceived as one who won’t fight back. We get a lot of mail and not all of it is positive. Some communications, like this letter, are downright inflammatory. “Hate mail” seldom contains constructive criticism or carefully considered opposing views so I usually ignore it but I’m going to respond to this letter because some of our readers may have been taken in by the same promotional hype that seems to have convinced Mr. Morrison that DVD-Audio doesn’t need to prove anything. Morrison believes that he can learn all about how audio products sound from reading the spec sheets, and some entry-level magazines support that belief with “ivory tower” theorizing in lieu of actual observation. I can imagine that any subjective review of sound quality might not make sense to someone who believes that you can evaluate the sound of a digital component or format by counting bits. Bits are bits, right? More bits automatically sound better, right? An equal number of bits will sound the same regardless of the format from which they come, right? By this “logic” I shouldn’t have bothered to listen to these products at all. Morrison writes that “it is unnecessary for DVD-Audio to demonstrate that it is the equal of CD” and that “24/96 cannot, by definition, make the sound worse,” that this “merely extends frequency response and dynamic range of the system; it does not introduce colorations.” This is a naive viewpoint that demonstrates a lack of both technical knowledge and listening experience. Has he considered encryption, “lossless” compression and watermarking? You won’t find any of these things on CDs but you may encounter all three on DVD-Audio discs. Could his champion long jumper jump 20 feet with a 75 pound. pack on his back? Call me a skeptic, but the jumper would have to actually demonstrate that ability to me because I won’t accept the word of his agent. Sony and Philips promised us “perfect sound forever” when the Compact Disc was introduced. Now they offer us the Super Audio Compact Disc which they claim is even better. Apparently the CD wasn’t perfect after all. Dolby’s AC-3 data-reduced compression scheme was promoted as being “completely transparent to the original master.” Now Dolby brings us Meridian Lossless Packing (MLP) which must be even more than completely transparent or why would we need it? MLP can’t cause any audible harm, say the pundits, because it’s “lossless.” Encryption and watermarking are inaudible according to the developers of these technologies. These are all advertising claims, not facts. Experienced readers are aware that products don’t always perform as well as the advertising copy writers would have us believe. Experienced reviewers approach all new products with skepticism. Less experienced individuals may accept the ad copy without question. Entry-level magazines may parrot the product literature and declare that all the products you see advertised in their pages offer unquestionable advancements in the state of the art. Rather than simply accepting advertising hype, I utilize two sensitive instruments, which are permanently attached to the sides of my head, to see if new products live up to expectations. This process is called observation and it is the cornerstone of science. Information gathered by observation is known as empirical evidence. So far—and I clearly stated in my articles that these are preliminary evaluations made with a limited selection of software—DVD-Audio has failed to meet my expectations. If the format completely satisfies Morrison, couldn’t he just say so without attacking me personally? I have written extensively about the performance potential of both DVD-Audio and SACD. My articles have described the technical details and differences between these formats and I have written about the theoretic advantages of extended bandwidth and dynamic range. I believe that these articles were as technically thorough as the magazine medium allows. One of the articles in Issue 43 to which Morrison refers was an opinion piece (DVD-Audio—Boon or Boondoggle) and the other two were product reviews which he obviously didn’t read carefully. I’ll quote directly from my articles in Issue 43. From ...Boon Or Boondoggle “In my reviews of the Pioneer and Technics DVD-Audio players, I have tried to relate my impressions of the sound of the players and the sound of the DVD-Audio format. These reviews are a preliminary evaluation made under hurried conditions with insufficient data about the recordings, but I’ve done the best that I could under the circumstances. The opinions expressed about sound quality are mine alone and may be useful as a listening guide, but you should listen for yourselves and make up your own minds about the validity of this new format and the quality of these new players.” And from the article titled Audio Perfection “I’ve been listening to 96kHz/24-bit LPCM recordings on DVD discs [DVD-Video standard without encryption] at home for some time now, and they are very impressive, too.......If there is a format war we can’t lose. Each of these new technologies can represent the biggest single leap in fidelity that I have experienced in my decades in the industry.” And from the Technics DVD-A10 review “....I am fully aware that you can’t judge a recording format from one or two discs, and that recording quality and mix quality vary tremendously, regardless of format. Because of the limited selection of software, I can’t make any definite statement about the sound of DVD-Audio as a format at this time. All I can do is report on what I heard and let you draw what conclusions you will.” Pretty biased, huh? For the DVD-Audio player product reviews I used my reference Wadia 860 CD player as a benchmark for CD performance. After comparing the sound of well known CDs played on the DVD-Audio players to the sound from the same discs played on the Wadia, I listened to sample discs in other formats played on the DVD-Audio players and compared the sound to CDs played on the same player. I reported on what I heard. That’s about as scientific as subjective reviewing gets. As clearly stated and quoted above, these are my opinions. If and when I hear a good-sounding DVD-Audio disc, I’ll certainly write all about it. As I stated in the review of the Pioneer DV-AX10, “The Pioneer sounded similar to the Sony SCD-1 [when playing SACDs]..... which is not surprising since Pioneer uses the Sony chip set to decode DSD material.“ Morrison’s rant about the Pioneer converting DSD to LPCM is simply wrong. DSD doesn’t require conventional digital to analog conversion and the Pioneer player has native DSD decoding on board. The rest of his letter is filled with so many confusing and misleading statements that I’m not quite sure where to begin. Here are the facts about analog inputs on AV receivers and digital controllers. All analog inputs, whether two channel or six channel, do one of two things. Either the analog signal is converted to digital at low resolution eliminating any sonic advantages offered by high resolution music formats like SACD or DVD-Audio, or the analog information is passed directly to the volume controls bypassing all digital processing. (This subject is thoroughly covered in my series on digital controllers in WSR.) Owners of systems based on AV receivers are unlikely candidates for upgrade to high resolution music formats as most receivers have insufficient resolution to take full advantage of even the current CD format, but the fact remains that the vast majority of the installed base of receivers are not compatible with the DVD-Audio format which requires six analog inputs for “high resolution” surround sound playback. Owners of systems based on separate stereo preamplifiers or digital controllers are much more likely to desire new, higher resolution music reproduction formats like SACD or DVD-Audio, and there are virtually no six channel preamplifiers or digital controllers with six-channel analog inputs in the installed base of these components. All stereo preamplifiers have analog inputs and most high quality digital controllers offer stereo analog bypass and are compatible with stereo SACD but are not compatible with DVD-Audio if, as Morrison says, surround sound is the primary selling feature of the later. Morrison’s statements about SACD being limited to two channels are incorrect, too. Although Sony originally introduced SACD as a stereo music format for “purists,” Direct Stream Digital technology has always supported multichannel recordings. Philips has recently introduced six-channel SACD players and Sony introduced two at the 2001 International Consumer Electronics Show (CES) in January. I have quite a selection of multichannel SACDs in my possession now. (Article upcoming.) SACD players don’t downmix multichannel recordings to stereo— a process that music producers abhor. Multichannel SACDs include a separate two channel mix along with the multichannel mix to allow uncompromised stereo reproduction. My comments about yet another format refer to the DVD player evolution. The first DVD players didn’t support DTS. The next generation lacked component video outputs. Then came progressive scan capability. Some early adopters may have purchased 3 or 4 DVD players already and now the major Japanese manufacturers are asking average consumers who are completely satisfied with CD-quality sound to buy yet another DVD player. Consumers with receiver-based systems will experience little sonic improvement from high resolution formats and we already have surround sound on DVD-Video discs in the form of Dolby Digital and DTS Digital Surround. The question that I posed in the opinion piece was simple (although Morrison didn’t understand it). What new benefit does DVD-Audio offer to consumers? In his zeal to attack me, he failed to provide any answer to that question. SACD is obviously aimed at a different market and general consumers will probably have little interest in the format but WSR’s motto is “the best that it can be” and SACD meets that standard in my opinion. I’m an audiophile and music lover and I make no attempts to disguise that fact. SACD is a music delivery format that offers outstanding sound quality based on my listening experiences. SACD has demonstrated dramatically better sound than what CD can provide. I have a compelling reason to buy an SACD player while others may be more attracted to DVD-Audio. Must we choose sides and write defamatory missives about those in the opposite camp? As an equipment reviewer, shouldn’t I write about both SACD and DVD-Audio? As a person, am I not entitled to have a preference? All of my statements make perfect sense to me and they are based on actual listening experiences. Morrison’s “logic” would have us believe that a $300 Chinese DVD-Audio player will offer state-of-the-art audio performance because bits are bits. Maybe it is Morrison’s personal bias or lack of experience that makes my point of view seem illogical to him. I think I am writing on the intelligence level of my readers and that most of them understand these subjects better than Mr. Morrison does. WSR readers can scan the manufacturer’s spec sheets for themselves and don’t need a magazine article that repeats numbers which are touted in every product ad. According to their letters, they want to hear the subjective impressions of an experienced listener who can compare the sound of a new product or format to an established reference standard component or format. That’s what I am and that’s what I tried to do. Opposing viewpoints written by thoughtful, considerate readers are welcomed by WSR but I think that personal attacks and “flames” are best left for the juveniles on the Internet. This is a serious magazine written by and for discriminating adults. I believe that adults in a civilized society can have differing opinions and still treat each other with respect.
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