One of the things that distinguishes a dedicated audiophile from Joe Q. Public is that he has some notion of what audio fidelity is all about.
The typical buyer of a "steeryo" is seeking nothing more than pleasant or exciting sounds, and is easily satisfied because he has no greater expectation of audio than this. The audiophile, however, is aware that reproduced sound can resemble (more or less) real, live sound, and he is driven in a continual search for that ultimate truth ("fidelity to the original") even while realizing, intellectually at least, that it is unattainable.
Because he understands what the word "reproduction" means, the audiophile thinks in terms of a relationship to an original sound. This original is, of course, the sound of live music, and the touchstone for its reproduction is accuracy. Unfortunately, though, we don't really compare the reproduction with the real thing—because we can't. Only a recording engineer can saunter back and forth between the real thing (which takes place in a studio or hall) and the reproduction of it (in the control room with its monitor system). We audiophiles must be content to compare the reproduction with what we remember to be the sound of live music. Even the amateur recordist must carry the memory of that original sound home with his tapes in order to evaluate them.
And that memory may not serve us that well. Few of us have learned to listen with enough attention and skill to be able to break live sound down into its components and to observe what each sounds like. Most of us remember only an overall impression—the gestalt of the thing. And many of us must admit, to ourselves at least, that we have not heard live music for years or, worse, never at all. For the vast majority of audiophiles then, the reference standard is not the absolute sound of live music, but an imagined ideal—a mental picture of how we remember its having sounded or how we would like it to sound. At this point, accuracy becomes a dubious criterion because of the vagueness of the original to which we compare the copy. System evaluation becomes a (simple?) matter of "it's good if it sounds good."
The problem with this is that one man's good is another man's distortion. Different people listen to and assign different orders of importance to different aspects of reproduced sound. Thus, while two very picky listeners may agree that a system has good bass, good highs, and a colored middle range, they will disagree as to how good the system is if one happens to be critical of highs and lows while the other is critical of the middle range.
In short, we really don't have any way of reliably assessing the accuracy of reproduced sound. Even a recording engineer cannot be confident of the sound of his own recording, because what he hears in the control room depends on his monitoring equipment, which is no more—and is often less—accurate than a home system. (Many pros do not, in fact, aim for realism at all, but for what they call a "commercial sound"—one that will sell. Thus a recording may not even have the potential for sounding realistic.)
All this does not, however, discourage audiophiles in their search for the Holy Grail of musical accuracy. There are a couple of approaches from which to select. The casual audiophile, who has more interest in music than the ultimate in fi, will usually choose a record label whose releases he favors for their musical values, and will tailor his system to sound best with most of that label's recordings. Discs from other labels may sound good on this system too, but it will be a matter of luck, and bear little relationship to accuracy.
Perfectionist audiophiles, on the other hand, usually aim for maximum accuracy in the playback system itself. The idea here is that, if the system accurately reproduces what is on the recording, the best recordings will yield the most natural sound. (This philosophy has the added benefit of rewarding those record manufacturers who strive hardest for realism.)
This seems like an elegantly simple solution, but there's a flaw. In order to ascertain the accuracy of a disc's reproduction, we must have an original to compare it to. But we can't compare it to the sound that was fed into the master-tape recorder, because that sound was gone forever when the recording session ended. The closest we can get to that original signal is the one that comes from the recorder when the tape is played back. That, after all, is the signal that was used to cut the disc, and if the disc sounds the same as the tape, then we know our record-playing system (the arm, cartridge, and preamp) is accurate. Right? Not necessarily—the record cutting and pressing system was optimized based on a comparison to the original sound, but with probably a completely different phono system than the one you use at home.
Before approving a new release, a record producer is sent a test pressing of it (footnote 1), which he then plays through his reference system and compares with what he hears directly from the master tape. If they don't sound alike, he tells the cutting engineer to make appropriate equalization corrections for the final release cut, or to simply re-cut the disc with the same equalization.
Wouldn't this ensure that his disc sounds like the original tape? Not quite, because it is more than likely that his phono system and preamp have significant colorations, which will make the disc sound different from the way it "actually" sounds. Why, then, should our perfectionist record producer trust his playback system? Because he carefully chose it to make his records sound as much as possible like his tapes!
We've all heard of Catch 22, but in case you're unsure of its meaning, it is about circularity—in reasoning, causality, and Ultimate Truth. Circularity exists when A is a function of B, while B is determined by A. A popular example of circularity is the chicken-or-the-egg question. Then there's the apocryphal "Timbuktu Paradox," which relates the story of the retired sea captain who fires a cannon every day at the precise moment the town hall clock says 12 noon, while the town-hall custodian checks his clock every day by the sound of the 12 o'clock cannon.
What in fact does a record sound like? Think for a moment before answering. It has no sound at all. Hold one up to your ear, and what do you hear? Nothing, of course. To hear what's "on" a recording, you have to reproduce it through a phono system. And what does that phono system really sound like? It sounds like the record with various things added or subtracted. And the music goes 'round and 'round..
There really isn't any way of knowing precisely what is the sound of a record or its player. This is one reason why, in this age of high technology, audio continues to be such a cabalistic field. Where knowledge fails, mysticism moves in.
But just because we cannot make absolute assessments of disc-reproduction accuracy doesn't mean we should abandon the accuracy criterion altogether, any more than we should all stop trying to be good people just because we can't be perfect. There is, in fact, a way we can get reasonably close to the ultimate truth about an analog disc and its player, and that way believe it or not is through the Compact Disc.
The CD has all along been touted as an absolutely accurate recording/playback medium, no doubt to the embarrassment of those manufacturers who so promoted it. Even the mass circulation hi-fi magazines have been reporting that some players sound better than others, and that the best are getting better as time goes on. But another question that has assumed growing importance is just how good the Compact Disc system actually is, because the answer to that question will determine how far the CD can go towards needs of the audiophile who cares about accuracy (footnote 2).
Numbers of audiophile-oriented record manufacturers have been claiming that the CD sound is "virtually indistinguishable from" the sound of the original master tapes. Even allowing for a certain amount of hyperbole (footnote 3), this would seem to indicate that a CD may offer us the most direct path back to the sound of the original master recording. But how much does a CD sound like its master?
To my knowledge, the only investigation of this was done a couple of years ago by England's Hi-Fi News & Record Review. Those listening tests involved direct comparisons between the sound of some Decca CDs and their digital master tapes. The test results were not felt to be entirely conclusive. While there was agreement that the CDs sounded pretty much like the original masters, there was some disagreement as to how important were the minor differences noted.
HFN/RR's experiment is already outdated anyway. Since that time the audio quality of the best CD players has improved dramatically, while many of professional recorders have stayed the same. And the conditions of HFN/RR's tests were not quite the same as an analog disc/tape comparison, because a set of spurious electronics were introduced into the "original" signal: the digital recorder's playback circuitry.
When mastering from analog, the original signal—that is, the signal feeding the cutting system—is already in analog form and can be auditioned directly. But in CD mastering, the original is in digital form, and stays that way up until the time the disc is played in your home. In order to compare the original (digital) with the playback (analog), D/A conversion must occur at the output of the recording deck. And there's the catch. That D/A converter and audio section was not present in the chain that delivered the original signal to the CD. In other words, when we make a CD/master-tape comparison, the "original" sound is being processed by electronics which are different from those used for the CD playback, and the former may not be as good as the latter.
Professional recording equipment is notorious for having less than perfectionist-quality audio circuitry and parts. That's why every recording studio that aims for the best sound customizes its tape decks. Some consumer CD players, such as the Meridian and Mission units, probably produce a better sound from CD digital than do the decks used to master those CDs. So it is more than likely that, if HFN/RR were to repeat those tests today, the CD sound would emerge as the clearcut winner, and would actually be judged better than the "original tape."
Under the circumstances, though, it is likely that such comparisons between the master and the consumer product are more reliable for digital recordings than for analog ones, because there are no mechanical transducers involved. Bad electronics can do some nasty things to digital sound, but they tend to have relatively little effect on the spectral balance of the sound—the balance between bass and treble, and the absolute high-end content. Thus, while we may still quibble over other aspects of CD sound, there is little doubt but that what we hear from a CD is much closer in spectral balance to the master tape than what we hear from an analog reproduction of the same recording.
This is why I adopted CD as my "standard" for judging most aspects of the sound of analog signal sources. Where CDs contrast consistently with what I hear from analog, I assume (on faith, you might say) that the CD sound is closer to the truth in spectral balance and low-frequency quality. If that CD sound is not "good," I do not assume that the better analog sound is "right." Instead, I adjust the other components in my system—the loudspeakers, in particular—until the sound I hear from CD in the listening room is as close as possible to what I remember of live music. This then becomes my standard for evaluating analog sources. The sound I get from analog is of a very high standard, and it has very similar spectral balance to digital sources.
The CD is still not what I consider to be anything like an "absolute" standard, but I do believe it is the closest approach to such an absolute that we're likely to find. It's certainly better than wondering whether the lovely sounds I get from some analog discs are the result of almost-perfect everythings in the chain, or merely a fortuitous mating between gross system colorations all the way from the microphones to the loudspeakers.
http://www.stereophile.com/asweseeit/363/