The Past Is Prologue
All of us are inexorably shaped by our personal histories. Baby-boomers like me lived through constant improvement in the reproduction of images and sound; as a result, we cannot escape from the idea that technological progress is inexorably allied to commercial success. My first record player was an acoustic wind-up model that played 78s. I am old enough to have lived through the change not only from radio to monochromatic to color TV but also, of more importance to this music lover, from the 78rpm record to LP, from LP to CD, from CD to SACD and DVD-Audio, and from SACD to DVD-A to Blu-ray and HD-DVD. I went from listening to mono records and broadcasting to the stereo experience from all media. Though I was not impressed with quadraphony when it was introduced in the mid-1970s, modern multichannel can offer a superbly realistic experience, as described by Kal Rubinson in his bimonthly "Music in the Round" column.
With the launches of Super Audio CD in 1999 and DVD-Audio in 2000, for the first time music lovers were offered media capable of capturing and playing back audio data with sufficient resolution and bandwidth to be capable of audio transparency: the culmination of the trail of improvement. Yet neither has succeeded in the marketplace. Instead, the public has voted with their money for downloads and convenience. With the exception of sporadic releases such as the Beatles' Love and a limited role in in-car sound, DVD-A is moribund. The advent of SACD led to a renaissance in classical recording quality—Telarc, Pentatone, Channel Classics, Harmonia Mundi, Linn, orchestral labels such as the San Francisco Symphony, even DG, RCA, and Sony (see "Recording of the Month," p.133), are all releasing discs that surpass the sound quality available from the "Golden Age" of classical recording. But classical record retailing is in the doldrums. SACD may survive in that specialist niche, but that survival is a limited form of success, I feel, suggesting that a new direction is necessary.
"New Directions in High Resolution Audio" was the title of a conference organized by the Audio Engineering Society and held at London's Queen Mary University at the end of June. I had been invited by DSP consultant Vicki Melchior to give a presentation at the conference; as I have found it much easier to make predictions about the past than about the future, I decided to offer some possible explanations for the commercial failure of the existing hi-rez audio media, before handing over to my colleagues on the panel—Arcam founder John Dawson, Linn recording engineer Philip Hobbs, Professor Malcolm Hawksford of the University of Essex, consultant Steven Harris of BridgeCo and one of the first engineers to point out the audio effects of word-clock jitter—to look at the future of hi-rez music playback in the home.
I have examined many of the reasons for the market failure of DVD-A and SACD in previous editions of "As We See It," and while there isn't room to reexamine those reasons here, I urge readers to check out what I wrote in May 1998, September 2000, May 2001, and May 2005. But the main reason for the media's demise, I believe, is what I wrote in this space in October 2002: that while both offer a wide range of features, many of those features failed to be perceived as benefits by would-be customers. "If the record industry doesn't allow SACD and DVD-A to offer people what they want," I concluded, "there is no law that compels them to become customers, no matter how much the record industry appreciates the new formats' benefits."
To succeed, a new medium needs to be different in kind, not just offer more of the same—even if that more is more better. And the potential for being better doesn't mean, of course, that that potential will be realized. Many of what were released as "high-resolution" recordings on both DVD and SACD had no more dynamic range and/or bandwidth than the same recordings on CD. Many of the universal players at both low and high prices had no more dynamic range than a regular CD player (though they did have the increased bandwidth). Both factors rendered the benefit of hi-rez audio encoding moot, meaning that high-performance multichannel capability was the only feature of SACD and DVD-A that had a chance of being perceived by consumers as a benefit.
Except that: 1) the majority of the relatively small number of customers who appreciate high sound quality are currently satisfied with two-channel; and 2) while the mass market does appreciate multichannel playback, even with compromised sound quality, it currently does so only in the context of video playback.
Meridian's Bob Stuart wrote a decade ago, echoing earlier work by the Acoustic Renaissance for Audio, that without noise-shaping, a minimum of 58kHz sampling and a word length of 18.2 bits were necessary for audio to be PCM-encoded with audible transparency (footnote 1), and there was a consensus at the AES conference that hi-rez audio encoding does offer a sonic improvement compared with the 16-bit/44.1kHz-sampled CD standard.
In his keynote address, for example, preeminent engineer Peter Craven demonstrated how digitally transferring a 78 of an electrical recording of an aria from Puccini's La Bohème, recorded live at Covent Garden on June 8, 1926, improved in sound quality when the sample rate was increased from 44.1kHz to 192kHz. Though it was difficult to hear in the reverberant lecture hall, at the highest sample rate, the inevitable surface noise, crackling, and distortion did indeed seem to float free from the mono image of the singer and orchestra compared to the lower rate, at which the noise and distortion seemed more wedded to the image.
In October I will write more on Peter's ideas about why this should be. I will end this month's essay by quoting, from a paper given at the conference, the results of experiments on the audibility of high sampling rates: "To achieve a higher degree of fidelity to the live analog reference, we need to convert audio using a high sampling rate even when we do not use microphones and loudspeakers having bandwidth extended far beyond 20kHz. Listeners judge high sampling conversion as sounding more like the analog reference when listening to standard audio bandwidth." (footnote 2)
So that's that, then.
Footnote 1: Robert Stuart, "Digital Audio for the Future," Audio, March 1998; reprinted in expanded form as "Coding High Quality Digital Audio" on Meridian's website.
Footnote 2: Wieslaw Woszczyk and John Usher of McGill University, Jan Engel of the Centre for Quantitative Methods, Ronald Aarts and Derk Reefman of Philips, "Which of Two Digital Audio Systems Meets Best with the Analog System?" Proceedings of the 31st International AES Conference, London, England, 2007.