Myth Statement
Measurements do not reveal fidelity

Many audiophiles like to embrace the myth that measurements cannot tell you what something will sound like. They like to reflect on the Total Harmonic Distortion competition that amplifiers follied with in the 1970's. True, in the early 70's THD was the only "quality" specification used, but it soon proved to be insufficient. If you look at the complete history, you would find that in the mid 70's a new quality measurement was introduced. This was Intermodulation Distortion. Striding for low THD's engineers chained together many gain stages in series and closed a global feedback loop around them. Intermodulation occurs when the distortion cancelling feedback signal arrives too late to make a complete cancellation. With the introduction of IM testing, the THD wars ended abruptly. And those horrible sounding amplifiers, started to sound nice again. We can all thank Crown corporation for that. You can google it: Crown IMA Intermodulation distortion meter.

History teaches us a couple of things. First it shows that no 2 people hear the same thing the same way. There were many who thought those 0.00001% THD amps sounded fine. But there were others that were certain something was wrong with them. For those that had doubts, some stayed with older designs while others pushed on and found a technical reason and a solution to their dissatisfaction. That is how progress works.

The moral of the story is, when you make the right measurements, you get the right answer. And when your ears tell you that something is wrong, hard work will generally find a measurement to match it. There is never any justification to not measure. None. If Crown never did the hard work, we would still believe that the only way to get good sound was with zero global feedback. And while there are those that still believe that, Crown proved that there was another way.

The same goes for turntable drive systems. When early direct drive designs were criticized for audible abberations, many turned away, and went back to belt drive while some of the larger companies took a look at how the motors were being controlled. There are many ways to control the speed of a motor, the main issue seems to be whether to read the platter speed with a linear generator or to make simple updates to the speed once or twice per revolution. The updating method, still used today, will produce wow and flutter numbers greater than 0.1%, the linear generator method drops that an order of magnitue to 0.01% which is truly lab grade by any standard.

There are those who will wax on about cogging and "hunting for speed" that all direct drive systems supposedly suffer from; But how then does all that cogging escape the wow and flutter test? Why are we lead to believe that only belt drives benefit from the "flywheel" effect! Of course all drive methods benefit from the flywheel effect. And not all direct drive systems hunt for speed.

One might suggest that this vanishingly low W&F measurement is just like THD, that something else, even more audible may be hiding from the measurement? And they would likely be correct. This is the cogging or hunting for speed they like to talk about. But that behaviour, if it exists, can be captured by the weighted Peak Wow and Flutter test. And as far as I know, only Technics evaluates and specifies a peak wow and flutter measurement.

So what makes the 1200 different from others? Just look at the owners manual specifications.

What led me to question all this was a review that appeared in a very popular magazine_1/. Within the review of a $6K belt drive table, a wow and flutter test measurement was taken. They would not publish the wow figure saying that they felt the number too high and likely the result of the test record being off center. But they then go on to say that they "confirmed the excellent flutter measurement of 0.15%". Well, that's not exactly correct because the maker states that wow and flutter combined is 0.15%, not flutter alone! With average flywheel effects wow is typically 6 times greater than flutter 2_/ . So while they did not give us the wow measurement, one can surmise from the flutter measurement that the wow was closer to 0.9%. The measurements actually show the 'table to be "out of specification". Was it defective? Not according to the review which was generally upbeat and positive.

This experience apparently discouraged the magazine from publishing any further turntable measurements. That's too bad. It should have encouraged them to do more. What has happened to our hobby that allows a $1.7K table from 1988 to completely smoke a $6K table from 2004 on technical merit? The answer is simple, it is the abandonment of measurements from the review process. The over reliance on the myth that measurements do not reveal fidelity.

1_/ Stereophile Vol.27 No.3, March 2004; Musical Fidelity M1 turntable & SME M2 tonearm
2_/ Audio Magazine July 1988 Review Well Tempered Turntable (Wow 0.12%, Flutter 0.02% Pg. 62)

More Measurements
What the hobby needs is more measurements, not less. Manufacturers should be able to explain why their products measure the way they do. Unfortunately it would appear that the hobby is more interested in letting the customer decide rather than giving the customer more information to base his/her purchase decision on. The problem with not having a performance baseline, is that it invites anyone and everyone to participate while leaving the customer at a decided disadvantage. And the editorial side of the hobby is no better. While we still see lots of measurements on cd players, and speakers etc, analog gets a free pass. Why is that?

Some important measurements:

  1. Wow and Flutter weighted and weighted peak
  2. Speed accuracy and drift
  3. Rumble, weighted and unweighted
  4. Tonearm bearing friction
  5. Plinth resonance testing
  6. Phono cartridge stylus dimensions
  7. Phono cartridge stylus effective tip mass
  8. Phono cartridge tracking ability

In summary
If your current turntable runs at a different speed each time you turn it on, ask yourself, how will you make sure the next one you buy is better in that regard? If your current cartridge mistracks on say, 5 records in your collection, ask yourself, how will you make sure the next one you buy doesn't increase that number? Because the way things are now, and with few exceptions, there is almost no way to answer those questions without first spending money. And while spending more money generally gets you a better refrigerator or automobile, it does not guarantee better analog audio.

We all know and agree that components "sound" different. And you have every right to choose a turntable because it has a certain "sound". But if you are trying to achieve a neutral lab grade analog playback system, one that lets you truly hear the cartridge and nothing else, you should be able to make that determination as well... before you spend money. And the only way you are going to do that is with the help of measurements, specifications and a review process that incorporates them along with subjective listening. Ed Long used to do just this very thing when he wrote for Audio magazine.

Myth Explained.