In fact most, if not all, wine judging is at least single blind, and usually double blind. And wine judges spit it out to prevent the wine tasting better the drunker they get. But it's still only a collection of opinions!
MrT.
wrote
I don't care anymore. :->)
Seriously, the original issue was whether a room mode is a resonance. Well, actually, the original issue was whether a magic resonator can improve the taste of wine. :->) But THEN it became whether room modes are resonances. And they most certainly are by every definition I'm aware of.
--Ethan
All the time. Almost all serious judging of wine is done under single- or double-blind conditions. And, yes, there are some surprises, such as Two Buck Chuck Chardonnay recently winning a prestigious California wine competition, but far more often than not "the usual suspects" do very well in single- and double-blind conditions. It's (usually) not without reason that famous wines become famous, though one of the fascinating things about wine is that each year is a different story. And why do you think that you can't get good wine in a screwcapped bottle? Some very fine wines are bottled under screwcap, and many winegeeks applaud the move.
Mark Lipton
-- alt.food.wine FAQ: http://winefaq.hostexcellence.com
messagenews:Y-mdnfg_VJGkiwnbnZ2dnUVZ snipped-for-privacy@comcast.com...
one taster doing repeated tests, and between different tasters. Highly UNLIKE audio testing.
"Mr.T" wrote
More like alchemy. No specific methodology. Groping in the half-light, hoping to stir up a new science.
A religion is a group of people defending the boundaries of received wisdom. Science becomes religion when it stops making progress.
Denying the possibility of progress in audio electronics is the stock-in-trade of the defenders of the reproductionist faith. Now accuracy of reproduction is commonplace their agenda is complete: there's nothing left to discuss.
That's why the audio forums are dead. They are populated by geeks with nothing left to say, save to chat about other things and defend themselves against the New Scientists of the Golden Age.
cheers, Ian
Audiophool.
"Mike Tommasi" in news: snipped-for-privacy@mid.individual.net :
(Among the population of audiophiles, I take that to mean.)
The gadgets with absurd rationalizations and ?27,000 price tags are legitimate gripes. (I could give you more real cases I collected. For an invited talk about this at a big technical conference. I reported only examples abject even on their own terms. Like a $10,000 or so preamplifier that, inside, had only a commonplace audibly dubious amplifier chip selling for a few cents.)
But the flip side to this is underappreciated in the technical world IMO. Some of these consumer technologies are rather complex, and skilled technical people not specifically expert may not perceive or understand their subtleties. Years of training to model reality with mathematical abstractions chosen partly for their tractability exacerbates this problem. You find engineers and scientists arguing from a textbook model for a reality it doesn't fit.
The original audio newsgroup years (net.audio from 1982, called rec.audio after late 1986) were a showplace for these behaviors (and audiophile myths and ideologies). Dick Pierce parodied some behaviors skillfully (from years working on practical audio) in his classic "Audio anecdote" posting series that many people enjoyed.
Skin effect in speaker wires is an example. (Tendency of current to flow near the surface as frequency increases.) Not every engineer knows offhand that this effect can be electrically important even at audio frequencies, especially with long runs driving an often complex speaker impedance. Quantifying skin depth is an undergraduate EM homework problem (links below). But discussions online (and in my experience, offline too) were full of offhand technical assertions that skin depth equated to EM wavelength of the signal, or even to air acoustic wavelength. It's neither, but people would argue "technically" from either assumption.
An even purer example is multiplying by -1 (known identically in the signal world as "180-degree phase shift"). In 1991 someone asked online how to do
180-degree phase shift on a sampled audio signal. A few people answered accurately at once, but were submerged and/or attacked by opinionated, mutually hostile technical assertions whose sole commonality was to be unfailingly wrong. (Did you hear the line about a little learning being a dangerous thing?)-- Max
Online audio skin-depth note from 20 years ago:
Arithmetic erratum:
Well if you think speakers are now perfect, recording techniques beyond reproach, and even room acoustics now universally faultless, then I guess you would imagine "accuracy of reproduction is commonplace". The discussion of course would be by the many millions who disagree with that.
MrT.
With the same group of tasters, yes. Between a different group of tasters, not so much.
Not so different really. Neither group likes to admit their personal shortcomings.
MrT.
Mr.T wrote
Even if you are right, that's just three areas of legitimate debate, whereas once there were many.
Commonplace and ubiquitous or universal aren't quite the same. It is certainly possible to find music and speakers that have been produced by fools and cheapskates, and played in awkward places by idiots, but the technology to produce the best, from the point of view of reproduction, is well known and won't be otherwise for the foreseeable future. There is no possibility of progress in design.
So gripes about incompetently designed products may continue, but there still won't be anything new to discuss in the reproductionist camp. They've done everything they can and are at the end of where it's got them.
I don't come here often, I should admit, but in audio newsgroups in general, how often do you see legitimate technical debates? There was an exception in rec.audio.tubes but now that is dominated by reproductionists (and a valve oriented reproductionist is daft or dishonest IMO) genuine discussion has almost disappeared.
The reason I don't come here often, it occurs to me, is encapsulated in the name of the group. No point here I suppose in asserting that the key question regarding domestic audio systems is about purpose rather than execution.
Perhaps the same could be said of science, engineering, economics, even history. As Gordon Brown pointed out, the role of politicians is now to serve rather than to lead: when there is nowhere else to go, there are no reasonable alternatives to consider.
Now we have the engineering, it's time to redevelop the art, I think. Wrong place to say so...I guess a moderator would have shut me up before now.
cheers, Ian
If the ringing due to the transient response of the system were excited at one of the frequencies it contains, then the system would resonate. Resonance is what you get when the input frequency is close to a mode, no? The mere existence of modes is not enough...
But, like "feedback", it is a term with several degrees of looseness.
cheers, Ian
But none of the systems I described have "modes." None of them have a resonant frequency. Yet they still "ring" by one definition being bandied about.
Construct a waveform from the following series:
F(t) = sum 1/n sin(nwt), n = 1, 3, 5, ...
and limit n to some number, oh, maybe 11 or 19. The resulting waveform rings. Is it resonating? Does it have modes?
Now that is beyond a bold statement, completely silly I would say.
Sounds like the patent lawer who said 100 years ago that everything that could be invented, had been :-) Even $100k speakers have their shortcomings, so I'm not sure why you imagine those priced at what normal people can afford cannot be improved on? As technology improves, hopefully we will see the prices get cheaper. However there is still the not insignificant matter of personal preference, physical size restraints, and any number of other individual compromises.
Which is only said by those with no alternative vision of course.
MrT.
Could be. Certainly, if you build an analog filter with a cutoff that is even a fraction as sharp as the one in a modern converter, you'll end up with a lot of L's and C's. It looks something like a collection of resonant filters. For example, the CDP 101 used an analog reconstruction filter and a schematic of it was in the service manual.
I see a *big* dip, right at the cutoff frequency.
Aside from the transition band.
There are no doubt some resonant circuits in the circuit. Some may even be resonating in the bandpass. My recollection is that the final low pass filter is based on what's happening in the tape head gap, which approximates a filter based on delays.
Often high quality analog tape recorders do things to midrange square waves that are pretty nasty looking. People who wince at the minor damage that
44 KHz sampling does should go ballistic.
In some ways.
IIRs seem to have internal energy exchanges that seem to harken back to simple LC circuits.
Agreed.
We are far from doing everything we can or need to do in the acoustic domain. In some ways, we are just starting out.
Good point.
IME preference predominates when practical perfection is elusive. The natural enemy of preference is practical perfection.
Example: Phono cartridges versus CD players. For a long time phono cartrdiges were pathetic things that as a rule were far from being practically perfect. Near the end of the vinyl era, cartridges got to be pretty good, and people often made choices based on other things than their preferences in say bass and treble balance. However, CD players started out very good and only got better and cheaper. A/Bing CD players has been a very boring pastime for about 2 decades.
Leadership is still an evolving technology, and one that is very relevant to politics.
Ian,
This is a good distinction. I've heard people argue that modes and standing waves are the same thing. But they're not. A room mode is merely a propensity to vibrate, but it's not the actual vibration nor is it a wave of any type. Mode is short for "mode of vibration," so it describes what WOULD happen when excited, as you correctly observed.
--Ethan
Arny,
LOL, this is why the "analog tape rules" crowd cracks me up. If they'd just admit it's an effect they find pleasing, I'd be happy and we could go our separate ways in peace. But no, they argue that analog tape is "better" than digital recording, and then when they can't back it up with actual science that resort to name calling. Likewise for vinyl enthusiasts. :->)
--Ethan
Surely, a "mode" in this context is what we in the physical sciences refer to as a "normal mode"? That is to say, a characteristic vibrational frequency of a system. They are easily arrived at if one knows the forces on a system by diagonalizing a force matrix.
Mark Lipton
-- alt.food.wine FAQ: http://winefaq.hostexcellence.com
That should be true for square waves at any frequency, no? It's a classic problem of Fourier analysis: representing a square wave as a sum of sinusoidal waves, which is what happens in any DAC.
Mark Lipton
-- alt.food.wine FAQ: http://winefaq.hostexcellence.com
Exactly, that's the mathematical side of it. Any finite bandwidth in a signal path exactly implies protracted tails in its time-domain response to transient signals ("square waves"). The sharper the bandwidth is limited, the more the tails look oscillatory. (Like a particular form of a Gibbs effect in Fourier synthesis, Mark.)
The human side is that we do not hear via time-domain waveforms. Therefore they are not very useful or intuitive for understanding perceptual effects in a signal path. But they are unsurpassed for gee-whiz value. People unable to interpret them have expressed shock at the ringing responses of bandlimiting filters (in digital-audio paths) since the start of audio newsgroups or earlier. It belongs in an FAQ. (I wonder what they'd ever do if they saw the transient response of a loudspeaker!)
Actually they have much in common. In serious writing by professionals in the business of measuring what people actually hear, they take great care to exclude suggestive or prejudicial biases from audio testing. This can be much harder with fine audio measurements than with wine tasting, but that does not alter its importance.
Those professionals tend to be in businesses dependent on what people actually can hear (e.g., telecommunications firms) rather than on what they can be sold (e.g., consumer audio-equipment firms), as a broad rule with exceptions. For an enlightening example of the real perspective of highly technical engineers on perceptual quality measures, look at Jayant and Noll's classic 1984 text _Digital Coding of Waveforms._ (Just how important the human, perceptual measures are to serious engineers in this field seems to be a well-kept secret among hobby audiophilia and, for that matter, among nonspecialist engineers.)
It happened that one of the genuine Bell Labs experts on what people can hear -- working on the boundary between signal theory and psychoacoustics -- was also among the first and longest audio contributors on the Internet in the 1980s. "JJ" was scorned and disbelieved by skeptics for many years (though, be it said, he gave as good as he got). He still surfaces occasionally, sometimes incognito.
Cheers -- Max
JJ? You mean that short little curmudgeon Jim Johnston?
-- % Randy Yates % "Rollin' and riding and slippin' and %% Fuquay-Varina, NC % sliding, it's magic." %%% 919-577-9882 % %%%% % 'Living' Thing', *A New World Record*, ELO
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