HELPING HISTORY TO REPEAT
By now, most people who purchase CDs are aware of the coding designations which indicate whether the CD was processed from digital or analog master recordings. While the codes are in broad use, a number of record companies have resisted this system because they feel many consumers will reject any CD not made from a digital master. Unfortunately, this is indeed a factor, for many people refuse to buy CDs which are not inscribed with the DDD code that indicates a digital pedigree.
I prefer to think of these analog/digital CD codes as an audio sophistication index. The truly knowledgeable audiophile and music lover knows that the digital origin of a recording is no guarantee of high-fidelity sound quality. Yes, Virginia, many superb-sounding, brilliantly engineered recordings were made before the advent of digital processing! Those who insist that their CDs carry the DDD imprimatur are denying themselves access to a vast treasure trove of music. I have pointed out that, prior to the CD's introduction, only a fortunate few had master or first-generation tapes to provide ultra high-fidelity music reproduction far beyond what was available from the very best phonograph systems.
Nowadays, when you buy a CD made from an analog tape recording, you can be fairly certain that the record company has used the original session master tapes, not the so-called "cutting masters," which were several generations removed from the original masters and were subjected to equalization to cope with technical constraints of the vinyl phonograph record. Needless to say, the digitally processed CD glaringly revealed all the sonic artifacts of this "quick and dirty" transfer method. Consumer complaints and competitive motivation forced the record companies to use original session masters in their analog-to-CD transfers. As a consequence, critics and consumers alike noted the improved quality of the sound on the CD, as compared to the sound of the same recording on the vinyl disc. In the transfer of original analog tape masters to CD, no generation losses, incremental increases in tape noise, or other sonic degradations occur. Thus, for all practical purposes, the CD is not a copy of the original analog tape master, but the sonic equivalent of the master itself!
Of course, there is still the matter of the condition and technical quality of the original session masters. Dolby A NR was introduced in 1966 and was quickly adopted for both classical and pop recording. But what about all the recordings made prior to 1966? After all, we had been recording direct to disc for decades, and had been mastering on tape since 1950. To transfer recordings of this vintage to CD, record company engineers have to juggle a lot of factors and decide whether to copy the original recordings "as is" sonic "warts" and anomalies notwithstanding-or apply some remedial processing to attenuate tape noise, hiss, and impulse noise. If some engineers opted for processing, most of the so-called "single-ended" noise-reduction systems produced modulation effects, which many people found more objectionable than the noise on the recording! Thus, at present, analog transfers to CD from Dolby A masters are generally quite good in respect to background tape hiss, while those made from pre-Dolby tapes and discs range from "tolerable" to distracting and annoying.
A wealth of musical riches exists in the vaults of the record companies. If these recordings could be transferred to CD using some sonically transparent processing that significantly improved their sound quality, this would open up a new world of musical enjoyment for consumers (and extra profits for the record companies). Enter the giant Philips recording and electronics company of the Netherlands, and an enterprising American company, Sonic Solutions, of San Francisco. Philips has been recording the great artists of the musical world for decades and, of course, is part of the company which co-developed the Compact Disc. Thus, it was to be expected that while currently engaged in an ambitious program of new digital recordings, they would also reissue their enormous analog catalog on CD. And, in fact, they have established a lower priced Silver Line series of CDs, featuring fairly recent analog recordings, a great many of which are encoded with Dolby A NR. Now, however, Philips is issuing what they call Legendary Classics on CD. The initial 15 discs, in the main, not only have historical significance, but are drawn from analog recordings considered to be extraordinary performances by some of the world's greatest musicians. Some of the performances go all the way back to direct -to-disc recordings, while others are on analog tape predating Dolby A NR. Obviously, with recordings of this nature, there were both steady-state and impulse-noise problems, and this is where Sonic Solutions stepped in with their unique new digital noise-reduction system. Called NoNoise, this system is claimed to remove tape hiss, hum, surface noise, clicks, pops, and other anomalies without adversely affecting the integrity of the original music signals. Philips engineers transfer the original master tape or disc to a new professional digital audio tape, which is sent to Sonic Solutions. There, the digital data from this tape is transferred to large computer disks, and Sonic Solutions engineers assess noise problems using special analytic programs.
If the recording contains clicks and pops, Sonic Solutions employs a program incorporating techniques developed in artificial intelligence research.
It identifies the clicks or pops, and recreates sound to replace the area they occupied. Since this work is reconstruction rather than removal, the precise duration of the original performance is preserved.
To reduce surface noise or tape hiss, Sonic Solutions engineers analyze the spectral composition of the underlying noise floor. Over 2,000 points in the audible spectrum are measured to yield an accurate estimate of the unwanted noise. A special computer program then uses this estimate to perform "microsurgery" on the sound, reducing the noise without affecting any subtlety in the original.
Over 53 million separate computations are performed on each second of sound. After processing, the "de-noised" version is rerecorded on a new digital tape. This tape is now the master for the usual processing to CD. In a manner somewhat analogous to digital tape editing (in which sections of the signal can be stored in a memory, and edits can be rehearsed until seamless, before committing to the final edit), the Sonic Solutions processor thus can manipulate and operate on the noise artifacts while in the digital domain.
The first CDs of the Legendary Classics live up to their name. How about a pairing of Maurice Ravel, in 1932, conducting the Lamoureux Orchestra on his famous "Bolero" and Sergei Prokofiev conducting the Moscow Philharmonic in a 1938 performance of his "Romeo and Juliet, Suite No. 2"? Compact Disc, of course, and mono, too! What an opportunity to hear their ideas on these famous works! Another CD features Sviatoslav Richter performing Mussorgsky's original version of "Pictures at an Exhibition" and other works, recorded in Sofia in 1959-mono again! Among others on this series, there's Pablo Casals--once more in mono-performing in Beethoven's "Archduke Trio," Bonn, 1958. I recorded Casals' last traversal of the Dvorák cello concerto, in stereo, in 1959, and speaking of that piece, the Legendary Classics line includes the great performance by Emanuel Feuermann (New York, 1940). Another gem is a 1962 recording of Pierre Monteux conducting the Amsterdam Concertgebouw in Beethoven's "Eroica." Yet another is the great George Szell conducting the Concertgebouw on Beethoven's Symphony No. 5 and Sibelius' Symphony No. 2 in 1966 and 1964, respectively.
(Here we have stereo recording.) The other Legendary Classics CDs are of equal stature and interest. They will be available in the U.S. soon.
Several British critics have reviewed Legendary Classics-the Mozart Requiem with Karl Bóhm conducting the Vienna Symphony Orchestra (recorded in 1956), Stravinsky's "Soldier's Tale" with Igor Markevitch conducting (1962), and Schubert's "Die Schóne Müllerin" with Gérard Souzay (1964). As reported in Gramophone, the reviewers were highly impressed by the recording quality and felt the NoNoise process did a particularly effective job of cleaning up these older recordings while leaving the musical values intact.
I am anxiously looking forward to these Legendary Classics CDs. If the NoNoise system lives up to its promise, it will afford all of us the opportunity to savor some great performances, with sound far surpassing that which was available when the recordings were originally issued.
(adapted from Audio magazine, Aug. 1988; Bert Whyte)
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