Working in the Front Line Page 4

Such attitudes tend to suppress freedom of thought and innovation. Furthermore, science is littered with discoveries which were largely accidental; had they been ignored simply because they did not conform to the status quo, the loss to mankind would have been incalculable.

Examples include the chance arrival of the airborne penicillium mold in a particular scientist's laboratory, while centuries earlier, Kepler had been attempting to solve the problem of planetary motion within the conventional paradigm. Ptolemaic and Copernican laws only allowed for purely circular orbits. Kepler's discovery that the orbits must be elliptical was something he could not wholeheartedly believe in, and he referred to it as merely a computational device, yet this discovery led to a wholly new framework of physics later developed by Galileo and by Newton.

"The active researcher must see beyond the imprisonment of the prevailing paradigm, and if so led by observation, he must be allowed to go beyond the boundaries of what is considered true or plausible."

"Science can benefit from a hint given by Nature only if there are open-minded scientists who grasp the significance of a hint."

"Serendipity supplies science with its blind edge...allowing transcend established frameworks of knowledge, established world pictures." (footnote 2)

This applies most strongly to the assessment and analysis of reproduced sound quality, where variables exist for which there is no good engineering framework.

Do CD players sound the same?
We will assume, for the purposes of argument, that all CD players under subjective consideration have correctly operating error protection, an excellently flat frequency response, near-perfect channel balance and separation, and, by present standards, negligible non-linearity or related distortions. Let us also assume that all have a low output impedance and a nominal output of 2V RMS for 0dB, full modulation.

Conventional wisdom tells us that these are essentially perfect sound sources; remember the original CD slogan, "Perfect Sound Forever." Yet my experience of a very large sample of 300 models, with approximately 30% of repeat auditions, has been that such CD players do not sound the same. Very little correlation can be shown between sound quality and exaggerated technology claims or lab measurements, even when the latter are of extraordinary sensitivity. For example, transfer linearity is routinely measured over a 115dB dynamic range, frequency response and balance to ±0.01dB tolerances, and distortion to a threshold 120dB below peak level.

However, great correlation is shown between the generic types of player, both in terms of absolute merit and detailed subjective characterization. It is accepted that there exists a genuine scale of absolute reproduced sound quality for audio equipment, which generally improves in proportion to the cost. In the case of CD players, a similar relationship for sound quality is also apparent.

Having begun a scale of subjective merit for loudspeakers using scores from 0-10, representing no merit at one end of the scale to the best possible at the other, I transferred this method of ranking to amplifiers. Some years and some 150 amplifiers and preamplifiers later, a problem developed. Equipment was improving, something regularly verified by returning to long-term references. The best-sounding models were now being marked in a more logarithmic fashion, bunched in the range between 9 and 10 on the scale. This could not continue indefinitely, and I decided to make the scale open-ended—to reassess the top performers, and to give them corrected scores which bore an observed proportional relationship to the earlier references.

Over the years, assessments have seen the current "state of the art" score move from the original "10" to "13," then to "18," and in 1990, to "24." The percentage ratings I give in published reviews are based on the state-of-the-art value in force at that time. A component currently earning a merit grade of 12 when auditioned, a budget design for example, therefore gets a worthy 50% overall rating in print.

A mental attitude can be adopted for assessing CD players which helps free the listeners from concerns about the medium and its fascinating technology. Since the music emanates from a constant source—the optical disc recording—and since it emerges at line level, fully equalized, it has proved to be convenient to consider a player as just another line stage in a quality preamplifier. A similar merit-assessment procedure and similar criteria are therefore used for CD players. Some 300 players later, this premise is still valid, and CD-player sound characteristics are closely allied to fundamental differences noted with various qualities and types of audio amplifier electronics.

The very first CD players scored in the 6-7 out of 10 range; they were clearly inferior not only to the best contemporary electronics but also to the better analog, black-disc turntables. This came as a huge disappointment to many enthusiasts, including myself, who expected great things from the CD medium, and who thought the merits of the technology were cut and dried. Though the early players were initially impressive sonically and most rewardingly automated, the pleasure gained from the silent surfaces and slick facilities gave way to subjective boredom and, ultimately, to significant listening fatigue. The syndrome I noticed with early CD replay is a common one among hi-fi fans, where the protagonist plays many excerpts from demonstration tracks, but never settles down to enjoy a complete performance.

Footnote 2: Kantorovitch & Ne'emen, Studies in the history of Philosophy of Science, Vol.20 (Tel Aviv).