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Top Ten Audio Lies


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30 replies to this topic

#1 of 31 OFFLINE   MarkStash

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Posted January 25 2004 - 03:49 AM

Link lifted from a thread in Audioholics.com

I read most of these points debated herein. Would be curious to hear reaction/s and rebuttals. He refutes bi-wiring, cables, speaker burn-in advantages, etc. Interesting read.

http://bruce.coppola...enAudioLies.pdf

#2 of 31 OFFLINE   Jack Briggs

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Posted January 25 2004 - 07:15 AM

This sort of discussion is not "Basics" material, which is why I'm moving it to A/V Sources.

#3 of 31 OFFLINE   RobertR

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Posted January 25 2004 - 08:24 AM

I'm in basic agreement with everything he says. What I object most to in audio is the strong tendency among many people to reject the scientific method in favor of personal anecdotes, marketing pressure, and outright mysticism.

Here's a similar document dealing with audio "urban legends" and some of the psychological basis for them:

http://bruce.coppola...rbanLegends.pdf

and a more technically oriented one:

http://www.dself.dsl....o/subjectv.htm

#4 of 31 OFFLINE   Chu Gai

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Posted January 25 2004 - 11:07 AM

To which I'll add the following link...

http://2eyespy.tripod.com/

where one can read about audio myths from someone who obviously has some financial means.

#5 of 31 OFFLINE   Nathan Stohler

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Posted January 25 2004 - 11:09 AM

Thanks, Mark. That was a pretty good read. I'm just trying to figure out why a 4-page pdf is 11 MB!

#6 of 31 OFFLINE   Mark All

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Posted January 25 2004 - 12:36 PM

Good link Chu, although the poor guy seems to be subject to some of the same delusions the rest of us are anyway. He's using Nordost interconnect cables instead of Radio Shack cables. Also, why does he insist on having his amps on stands? Something wrong with the floor? Posted Image

I hadn't seen the Legacy speakers anywhere outside of magazine ads before. They look pretty good in a real setting.
Audio, ergo sum.

#7 of 31 OFFLINE   Jonathan Dagmar

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Posted January 25 2004 - 02:49 PM

Gee. 11 mb? Sorry, I don't have time for that.

I sure hate it when people use PDF files for no reason.

#8 of 31 OFFLINE   Angelo.M

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Posted January 25 2004 - 03:22 PM

Couldn't open the link Mark provided.

I think my Tice Clock is interfering with my Internet connection!

Or is it my Shakti Stone? Perhaps I'll paint my router green...

Posted Image


#9 of 31 OFFLINE   Chu Gai

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Posted January 25 2004 - 09:35 PM

Eyespy used to post (maybe still does) over in audioreview.com in the forums. He owns what he does not for the reason because it may sound better but as he's stated there on numerous occasions, because that's what he wants. In other words it's a matter of personal preference as opposed to sonic virtues.

Yeah, that's one hell of a pdf. I don't think it needed that much resolution.

#10 of 31 OFFLINE   Garrett Lundy

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Posted January 26 2004 - 01:17 AM

I must be new here.... how was painting things green supposed to make them sound better?
"Did you know that more people are murdered at 92 degrees Fahrenheit than any other temperature? I read an article once. Lower temperatures, people are easy-going, over 92 and it's too hot to move, but just 92, people get irritable."

#11 of 31 OFFLINE   Stephen Weller

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Posted January 26 2004 - 01:37 AM

Quote:
how was painting things green supposed to make them sound better?


It's True! It's because green is in the middle of the visible light spectrum, the photons are faster on average. Faster than red, but slower than blue.

It's not easy being green.












[rant]Sorry! I just couldn't wait until April 1st!!![/rant] Posted Image

#12 of 31 OFFLINE   Jack Briggs

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Posted January 26 2004 - 03:56 AM

And it gets tough coming up with more cynical, pseudoscientific nonsense to push on gullible people.

I think my Tice Clock is interfering with my Internet connection!


No, Angelo. It's a karmic thing, I am certain. The Tice clock is supposed to bless only your audio system. Or your Internet connection may be interfering with the Tice Digital Clock's ability to massage and bless soundwaves in your listening room. Best to move the computer to another area of the house. Karma is everything.

#13 of 31 OFFLINE   Chu Gai

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Posted January 26 2004 - 07:07 AM

With myths, the evidence never materializes (pun intended). Despite decades of research to uncover some of these things we're told it's just around the corner or that it's beyond testing or that it's just not understood or that science isn't evolved enough to understand it. We all wait for the smoking gun. The explanations run the gamut.

The difference is obvious.
It takes very careful listening.
Some people's hearing is better than others.
It takes very resolving equipment and your equipment just doesn't cut the mustard.
You've never heard my system, it's completely analog.

In the end it comes down to an insult and an upturned nose that'd make a foreign waiter proud. If you've got an opposing view, you're just not with it.

#14 of 31 OFFLINE   Saurav

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Posted January 26 2004 - 09:32 AM

Looking through the "Science and Subjectivism in Audio" link that Robert posted, there's one specific point in the 'Articles of Faith' section I don't agree with.

Quote:
"Sinewaves are steady-state signals that represent too easy a test for amplifiers, compared with the complexities of music."

This is presumably meant to imply that sinewaves are in some way particularly easy for an amplifier to deal with, the implication being that anyone using a THD analyser must be hopelessly naive. Since sines and cosines have an unending series of non-zero differentials, "steady" hardly comes into it. I know of no evidence that sinewaves of randomly varying amplitude (for example) would provide a more searching test of amplifier competence.

I believe this outlook is the result of anthropomorphic thinking about amplifiers; treating them as though they think about what they amplify. Twenty sinewaves of different frequencies may be conceptually complex to us, and the output of a symphony orchestra much more so, but to an amplifier both composite signals resolve to a single instantaneous voltage that must be increased in amplitude and presented at low impedance. The rate of change of this voltage has a maximum set by the frequency response and amplitude capability of the channel and is not generally greater for more complex signals; you do not get hgher slew rate with bigger orchestras. You must remember that an amplifier has no perspective on the signal arriving at its input, but literally takes it as it comes.

I don't think that is correct. Off the top of my head, I can think of a few things that you cannot test with a single sine wave:

* Intermodulation distortion, which is the result of the interaction of multiple frequencies with each other.

* Phase behavior - with a single test tone, you will get a fixed delay between input and output. You cannot test if this delay is constant with frequency unless you run a sine wave sweep, or use a different input signal.

* Settling time - Assuming the amplifier isn't push-pull class A over its whole operating range, a large current demand will make the power supply sag. It'll take a finite amount of time for the supply voltage to get back to its steady state (which would be the idle bias point for the active devices in the amp). Some poorly designed power supplies will even oscillate a little while returning to the steady state. Sine waves at constant amplitude will not show this aspect of an amplifier's behavior.

The whole concept that all an amplifier is doing is taking a single voltage at an instant in time and amplifying it (so all you need is adequate slew rate for the highest frequency at the highest power output) is overly simplistic, IMO. If that were reality, or even a close approximation of reality, harmonic and intermodulation distortion wouldn't exist.

I believe a square wave represents a much better test of any electronic component. It consists of multiple frequencies at specific relative amplitudes and specific relative time/phase relationships. You'll get a much better idea of an amp's frequency and phase linearity by seeing how well it reproduces a square wave, instead of viewing its performance with a sine wave.

Comments?

#15 of 31 OFFLINE   Angelo.M

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Posted January 26 2004 - 03:54 PM

Quote:
Karma is everything.


Jack, nothing's been quite right for me since I burned my Audiophiles Anonymous membership card and buried the decoder ring. Nothing but bad juju for me.

But, at the very least, I gave up these habits:
  • I don't shine green, red or blue light on my CDs.
  • I sold the Bedini Ultra Clarifier.
  • No more square strips of paper on the speakers.
  • I got rid of the pyramids that were, strategically of course, deployed around the room.
  • Gone are the days of isolating speaker wire with porcelain.
  • Magic Brick? What Magic Brick?
  • I removed the chewing gum that was dampening the crystal in the CD player.
  • The ceiling is now devoid of any polycylindrical objects.
  • The Mbongo Dots are banished, as are the Elephants Feet.
I need some sleep.


#16 of 31 OFFLINE   Chu Gai

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Posted January 26 2004 - 08:04 PM

You might be taking this, "Sinewaves are steady-state signals that represent too easy a test for amplifiers, compared with the complexities of music." out of context Saurav. I think the point was that music in and of itself does not constitute a more rigorous means of evaluation for an amplifier as opposed to test signals. That said, I don't think the single numbers that are given are in and of themselves particularly useful. Even in your example regarding slew rate and oscillation, most tests are done into a static load. I wouldn't mind seeing something like 3 speaker loads being simulated with circuits to provide an impedance varying frequency load for measurements to be made. Simulated in-situ testing if you will. It'd certainly give end users, once they knew how to interpret the results, a better idea of how suited an amp was to a particular set of speakers. Myself I find the whole phase error worries kind of funny because while we sit, debating its audibility and worried that it's constant across the frequency band (well it would be nice that they're at least the 'same' in both sound paths so you don't get artifacts), we totally neglect everything else that affected the phase. Like the instruments that were used, the microphones, the various amplifiers, the mixing that occurred, what you're playing the music back on, and the list goes on. Out of an amp, it takes a fair amount of phase shift to be audible.

Although you've banished elephants feet, during a recent trip to the supermarket for yardbird I found that they're now selling chicken feet. You might find those a competent substitute.

#17 of 31 OFFLINE   Saurav

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Posted January 27 2004 - 01:39 AM

Quote:
I think the point was that music in and of itself does not constitute a more rigorous means of evaluation for an amplifier as opposed to test signals.

That depends on the test signal, does it not? The all too common "THD with a 1KHz signal at full power" measurement is pretty much meaningless, I think you agree with me on that. Ditto for THD @ 20Hz and THD @ 20KHz - slightly better, but still a far cry from what is needed.

Quote:
It'd certainly give end users, once they knew how to interpret the results

And that is the crux of the problem, I think. Everything is being dumbed down to the point where the lowest common denominator in the buying population can feel that they understand what's going on.

Quote:
Myself I find the whole phase error worries kind of funny because while we sit, debating its audibility and worried that it's constant across the frequency band (well it would be nice that they're at least the 'same' in both sound paths so you don't get artifacts), we totally neglect everything else that affected the phase.

That's a good point, but good phase behavior is a good thing to have, just from a solid engineering standpoint. Also (though this is something a competent amp designer should have taken care of), depending on how many stages your amp has and where the global feedback loop goes to, too much of a phase shift can turn negative feedback into positive feedback, turning the amp into an oscillator. So it's not just about how much phase shift is directly audible.

#18 of 31 OFFLINE   Chu Gai

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Posted January 27 2004 - 02:23 AM

Yes it is and not tough to do. After all something as pedestrian as say Crown professional amps do 10 degrees. It really depends how much a person wants to agonize over this.

#19 of 31 OFFLINE   Saurav

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Posted January 27 2004 - 02:38 AM

Now that, is very true Posted Image

#20 of 31 OFFLINE   Rich Malloy

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Posted January 27 2004 - 04:57 AM

Quote:
Eyespy used to post (maybe still does) over in audioreview.com in the forums. He owns what he does not for the reason because it may sound better but as he's stated there on numerous occasions, because that's what he wants. In other words it's a matter of personal preference as opposed to sonic virtues.
You say that as though "sonic virtue" could mean anything other than the subjective value judgment of a human listener.

FWIW, I also prefer Nordost cables to Rat Shack, but they sounded a bit too lean in my system. And there's no way I'm paying that much. Posted Image

Different products sound different, and companies put great effort into making theirs match the preferences of their target market. Nordost or Rat Shack? Copper or silver? SET and Lowthers or massive monoblocks and Legacies? What's your preference?

I didn't open the list, but I wonder if this myth is on it: "All [insert audio product here] sound the same, regardless of price." Only someone who's never listened could believe such a thing.*

*(And, certainly, you might prefer Rat Shack to Nordost in your system.)
"Only one is a wanderer;
Two together are always going somewhere."


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