The 2011 Richard C. Heyser Memorial Lecture: "Where Did the Negative Frequencies Go?" Is There Something There?
Over the almost 35 years during which I have taken part in or organized listening tests, I have become convinced that what is fundamentally important is to respect the listenersto listen to what they tell me. Yes, there may be a trivial explanation for what they hear. But there may be something there. When I first heard of so-called LP "demagnetization"where an LP sounds better after being subjected to the action of, for example, a bulk tape eraserI was skeptical. But I didn't dismiss the reports; I just filed them away for further investigation, if and when I had the time: it is never clear where the science ends and the silliness starts!
Then, inadvertently, I took part in a blind test examining this very factor. I was visiting one of my reviewers, and while I was setting up my speaker-measuring gear in the vestibule outside his listening room, he was playing LPs to my assistant, Stephen Mejias. There was a short delay after one cut, then it was played again. From where I was in the vestibule, it had more bass.
"Was that a different pressing?" I yelled.
"No, we demagnetized the LP before playing it again."
Okay, so I heard a difference from something that, to the best of my knowledge, could not produce any difference.
Back to the first-principles thing. There are two facts:
1) The reviewer took the record off the turntable, "demagnetized" it, then played it again.
2) I heard a difference.
I could think of three hypotheses to explain these facts, one involving what was done, one involving what it was done to, and the third involving the listener:
1) Subjecting an LP to an intense AC magnetic field that decays over time does something that produces an audible change?
2) When you play an LP soon after an earlier play, the prior deformation of the groove walls changes the sound when it is played again?
3) As Stereophile writer Art Dudley has said, perception is not a linear continuum: The second glass of wine doesn't taste the same as the first, and the sixth glass of wine definitely does not taste the same as the second.
Which one (or more) of these hypotheses is correct? I have no idea. More work is required, and I am happy to leave that work to others. In any case, the cost of a Benjamin bulk tape eraser is low enough that if there is a real benefit from "demagnetizing" LPs, it is not going to break anyone's bank. So I filed away that day's events in my Perhaps file.
As I wrote in Stereophile 20 years ago, "If a tweak sounds unlikely but still costs very little, then try it. Why not? The price of admission is low enough that even if the effect is small, the sonic return on the financial investment is high. You can enjoy the improvement while reserving judgment on the reasons why.
"If the price is high but the explanation offered for any sonic improvement fits in with your world view, then try it. Your intelligence is not being insulted, and you can still decide that the improvement in sound quality is not worth the number of hours you have to work to earn the money to pay for it.
"But when the price is high and the explanation is bullshit, life's too short! File it away in your Pending tray until someone else you trust tries it out. Either the effect will be real and the price will fall as commercial success comes the inventor's way, or the effect will turn out to be as fictitious as the explanation."
But what puzzled me was the reaction of others when I published the account of this inadvertent blind test:
"You didn't hear a difference!"except that I did.
"There's nothing in an LP to be demagnetized!"except that the carbon black used to make LPs black is often contaminated with iron. (If that matters.)
"You were hearing what you expected to hear!"except that I had no expectations. I wasn't even in in the room, nor was I aware of what I was listening to. And as a listener, you must throw yourself open to what your ears are telling you without your brain intervening. The Placebo Effect works in both directions, in that it is possible for people not to hear what they don't expect to hearmore on this vexatious topic later.
All I had were my three hypotheses and an agnostic attitude as to which one of them was correct. To return to Richard Heyser, "I no longer regard as fruitcakes people who say they can hear something and I can't measure itthere may be something there!" I take seriously all tweaks that someone, somewhere has found to result in a sonic improvement. Some will turn out to be bogus, but there are those magic few whose effects are real. The absence of rational explanations for these effects shouldn't prevent audiophiles from appreciating their sonic benefits.
The Golden Rule for listeners: To thine own ears be true.
An example: When I was preparing Stereophile's Concert CD in 1994, I received reference CD-Rs from the mastering engineer, who awaited my approval of them before starting the plant's presses rolling. To my surprise, though the engineer had assured me he had not used any equalization or compressionall he did was to add the PQ subcodesthe CD-Rs sounded different from my masters. I ripped the CD-R data and compared them against the original data. Not only could I not null the production data against the archive file, the production master was longer by one video frame (1/30 second) for every 20 minutes of program.
Examining the difference between the files, I found that all the changes made to my data were at such a low level30dB or more below the analog tape hissthat you would think that whatever the mastering engineer had done, the differences introduced should have been inaudible. Yet what had alerted me to the fact that the data had been changed was a change in sound qualitya change that I heard even without having the originals on hand for an A/B comparison!
Such differences in sound quality are often dismissed as being due to expectation. But note that I was emotionally and financially invested in wanting the reference CD-R to sound the same as the originals. If I were to hear any difference, it would both cost Stereophile a lot of money to have the project remastered, and delay shipment of the CDs. In fact, it took time to work through the cognitive dissonance to recognize that I was hearing a difference when I expectedand wanted to hearnone.
Yes, what you think you are hearing might by dismissed as being imagination, but as the ghost of Professor Dumbledore says in Harry Potter and the Deathly Hallows, "Of course it's all happening in your head, Harry Potter, but why on earth should that mean that it is not real?"