> The logical fallacy here is to equate "disc quality" with the perception of music.
Ah, yeah, that's the point for those of us who must make a living dealing in facts. I think most of
us operate under the assumption that the higher the disc quality (ie lack of digital errors and
mechanical stability), the more output = input. As I've said repeatedly, if the input is of bad
sonic quality, digital media and digital conversion will certainly preserve and not mask those flaws
as much as older analog technologies, which add distortions (some apparently very euphonic to some
people) and mask or "soften" some flaws at the input end (again, this is found to be euphonic by
some people). So I again submit that many of the "digital sucks" crowd are igorantly confusing bad
human craft and bad human decisions on the input end with what they hear on the output end and
blaming the machine.
But, let's see if we can put these different world-views to some quantifiable testing. Bruce, I
really want you to take Jerry's offer. What's to be afraid of -- I think some very interesting
things could be learned by everyone involved and Jerry has made a very generous offer of his time
and equipment. I suggest we can use test gears and test ears. You guys buy two copies of a few
commercial CD's -- choose a couple of titles each, and I think the tests would be best if you chose
something you're familiar with and consider a decent-sounding recording. Keep one copy wrapped up or
have it dropped-shipped to Jerry (in other words, Jerry should test it right out of the shrink-wrap,
so it goes into his machines just like it came out of the store). Take the other copies and apply
these various treatments, keeping careful notes as to what treatments were applied. I think you'd
want to stick to one type of treatment per disc but maybe not? Let Jerry submit both discs to his
rigorous tests (please research Jerry's lab if you don't believe me that his tests are rigorous).
Then I would let a third party take possession of the discs (trust and verify, ya know) and all of
you make your way to the ABX comparison setup of your choosing (there was a very good one designed
by the Boston Acoustic Society described in a recent JAES article). Listen and find out first of all
if there IS an audible difference between treated and untreated discs. And if there is, let everyone
keep careful notes as to what they prefer. Then let's compare the results with Jerry's scientific
analysis of things like error rates and mechanical stability. Perhaps we can learn a few useful
1. what variances in laser-disc interactions are effected by polishing? Do they create higher or
lower error rates? Do they effect laser mechanics at all, and if so positively or negatively
vis-a-vis error rates? Is there an audible difference in ABX testing between polished and unpolished
2. does shaving the edge of a disc improve stability? Does it effect error rates or laser-disc
interactions? Is there an audible difference in ABX testing?
3. I guess we should ask if degaussing outright ruins a disc -- Scott's experience seems to indicate
yes but I suspect the kind of degaussing sold as a "treatment" uses a much less intense magnetic
field. So, if the disc isn't outright ruined, is the error rate or mechanical stability effected? Is
there an audible difference in ABX testing?
4. finally, and this would be the most interesting factor to examine -- I dare say it fringes on a
"perception" study -- was there much agreement about any differences in sound? This would be
particularly interesting and I'll certainly admit surprise if there IS a statistically relevant
perceived differences in sound but no statistically relevant differences from Jerry's tests. I doubt
that will happen but I'm never saying never.
5. this one is also very interesting, at least to me -- are discs found to have higher error rates
or less mechanical stability in Jerry's tests preferred sonically in the ABX tests? This gets into
the question, are there euphonic "problems" in digital systems akin to the harmonic distortion in
tube gear that some find euphonic? Again, I doubt this but again I'm never saying never.
So, what do you say guys? Let's see if we can get the laboratory and the listening room to meet in
the middle here. I bet if someone forwards this thread to the BAS guys who wrote that JAES article
they'd be game to get a crowd together for ABX testing. The only way we'll get answers is to do some
testing. Jerry's opened the door, Bruce you should walk through it.
Extra gravey -- this might make a very good ARSC convention presentation.
-- Tom Fine
----- Original Message -----
From: "Bruce Kinch" <[log in to unmask]>
To: <[log in to unmask]>
Sent: Wednesday, January 23, 2008 3:42 PM
Subject: Re: [ARSCLIST] Ampex ATR-102 opinion (was MD5 Hash Generators
> On Jan 23, 2008, at 6:28 AM, Jerry Hartke wrote:
>> Some writers have technical skills, while others spin out profitable junk
>> for acceptance by gullible editors and readers.
> Full disclosure, I have been an a occasional reviewer for both print and on-line audio journals.
> It is not a profitable avocation, and I have never claimed technical expertise beyond that
> available to any informed consumer. I don't consider anyone who investigates any issue gullible
> per se, which is unfortunately the frequent opinion of many who claim special knowledge in any
> field. That seems arrogant to me. However, having access to CES and other venues, I have not
> infrequently heard effects I cannot easily explain. Not all such changes seemed to be
> improvements, and some that were hardly seemed worth the cost. But then I drive a Mazda, not a
> Porsche for the same reason. I have friends who disagree and preferred to pay the difference. Are
> they gullible, or just happy?
>> De-gaussing (there are no
>> ferromagnetic materials in a disc), polishing (introduces millions of
>> microscratches that distort the laser beam), and trimming (can worsen track
>> eccentricity or unbalance), have the potential to degrade, but not improve,
>> CD or DVD disc quality.
> The underlying assumption here is that a class of objects produced by multiple agents at the
> lowest possible cost will have no functional flaws that can be remediated after market. The only
> other consumer category I can think of that makes such claims would be the purveyors of religious
> texts - the Bible, the Qur'an, and whatever the Scientologists keep by bedside and toilet.
>> If this remains an issue, Media Sciences would be
>> glad to participate in a controlled test on a few discs, both before and
>> after the "improvements", at no charge and then publish the results online.
>> Please contact me if you wish to participate.
> The logical fallacy here is to equate "disc quality" with the perception of music. I switched from
> physics to psychology as an undergrad because the girls in class were prettier. But I quickly
> realized that while the physics lab experiments were straightforward, experimental psych projects
> in perception had a lot of independent variables that could not be controlled. I appreciate that
> in itself can drive some people crazy.
> Again, there is ample documentation that some but not all auditioners can and will hear a change
> from a variety of treatments, tweaks, and widgets. Some perceive the change as a worthwhile
> improvement, others don't. That is normal, not something to get huffy about. If you are curious
> about such things, please do look into them.
> That this topic keeps re-surfacing, I suspect, is the result of a certain lingering
> dissatisfaction among listeners familiar with the sound of acoustic music in real space with the
> electronic and and particularly digital reproduction of that music. The response is essentially a
> desire to find something - anything - that will ease that disappointment. Tom Fine started the
> discussion by blaming the engineering, not the technology, for the the problem. I take a broader
> view, as I believe the limitations of CD reproduction are obvious in comparison to higher
> definition digital as well as analog, to say nothing of the real thing.
> Conversely, many folks (like my kids) who grew up listening to amplified instruments and entirely
> digital media have different criteria. They prize the loud, the clean, and the convenient. Here
> the iPod trumps even the CD. The logical extension of a "bits iz bits" definition of perfect
> sound is to have the marketplace decide how much more data can be thrown out and still fool a
> listener into thinking it is music.