Why Do People Come To Computer Audiophile To Display Their Contempt For Audiophiles?

[Jud]

1 hour ago, semente said:

 

Are they better? They don't measure better...

 

For some measurements, anyway.

[Jud]

1 hour ago, jabbr said:

Dude, you were brought up wrong ...

 

Ooh, and it vibrates.

[Jud]

4 hours ago, Sal1950 said:

"The output impedance was relatively high for a solid-state design, at 0.5 ohm from 20Hz to 20kHz. As a result, the response with our standard simulated loudspeaker varied by ±0.35dB (fig.1, gray trace)."

 

.35dB with a simulated loudspeaker - say it ain't so!  Obviously trash and unlistenable, and no other measurements can redeem that.  So it's now plain that Nelson Pass doesn't know what he's doing.

[Jud]

7 hours ago, esldude said:

Recording with a microphone is not going to cut it for comparing electronics unless differences are very large.  You could do it as a first step.  Having the ADC tap the speaker posts while each amp is in use should show you which is more accurate compared to the input signal. 

 

Which measurements would you want for accuracy, and do you have studies or data on how these correlate with human perception of sound in general or yours (in your system) in particular?

[Jud]

8 hours ago, pkane2001 said:

Record both using a calibrated measurement microphone positioned near the speaker using a quality ADC. Use the same bits and sampling rate as the original. Take equivalent small portions of the two recorded files and compare them to the original. Adjust levels and phase so that the recordings match the original as closely as possible. Whichever one reproduces more of the frequencies and amplitudes correctly is the more accurate one.

 

 

When you say "amplitudes," are you including phase?

[Jud]

7 minutes ago, pkane2001 said:

The measurement I'm suggesting is the difference between input and output.

 

Right - but the difference between which inputs and which outputs?

 

For example, let's talk about phase, and say you are comparing two different speakers, or sets of speakers.  Due to different crossovers, you may get both (sets of) speakers altering phase from input.  Is one alteration "more accurate" than the other?  Does one alteration sound more accurate to you than the other?

 

Or comparing DACs, which use different filters: Can you even hear time domain differences between the filters (e.g., ringing or its effects)?  Or if there are differences in the frequency domain, are both satisfactory in terms of intermodulation/harmonic distortion?  Are you particularly sensitive to certain types of distortion, and do you measure for differences in these?

[Jud]

9 hours ago, pkane2001 said:

Adjust levels and phase so that the recordings match the original as closely as possible.

 

By the way - As esldude has found in doing some of his difference measurements, timing may need to be adjusted between files to achieve the closest match (deepest “null” when reversing polarity of one file to get a difference signal).  How certain can you be that you aren’t washing out real phase differences when doing this?

[Jud]

1 minute ago, mansr said:

Are you referring to slight clock differences between devices and run to run?

 

 

Yes.

 

1 minute ago, mansr said:

For comparing two amps, this can be avoided entirely by recording both simultaneously on two channels of the same ADC.

 

Thank you.

[Jud]

10 minutes ago, pkane2001 said:

 

Jud, you are changing the subject. My post was in response to @jabbr about measuring differences between two amps to determine which one is more accurate.

 

Yep, let's take amps.  My speakers, as my sig says, are Vandersteens.  Let's assume for the moment that Vandersteen's marketing about the impact of time and phase "correctness" (including linear phase crossovers) on imaging and localization is true.  I'm looking at a Class D amp, say something NCore-based.  I assume (someone please correct me if I'm wrong) that some circuitry in a Class D amp must in effect do filtering to get the analog electrical waveform as output, and that this filtering has phase characteristics.  Are there published measurements for the NCore amps that will tell me this?  When people do measurements on Class D (or other) amps, is this something they commonly measure?  Is the phase behavior of an amp something you have bothered to measure in the past?

 

[Jud]

6 minutes ago, mansr said:

If this is the case, it must be compensated for before some types of comparisons can be done with any validity.

 

I'm supposing "strongest correlation" and compensation for clock drift can involve judgment, though my assumption (not having done such measurements myself) is that where the correlations fit is pretty obvious, so I don't want to make overmuch of the judgment aspect.

[Jud]

13 minutes ago, pkane2001 said:

You are still trying to take this into a direction that is orthogonal to the original discussion. Regardless of what speakers you use, amplifiers will add some distortion to the signal. Measuring which one adds less distortion before the speakers is measurable. Measure this into an 8Ω resistor. Or, measure this into an actual speaker. As long as the load remains the same (same resistor or the same speakers) and you swap amplifiers, you can measure the differences between them.

 

Hi Paul -

 

I don't think it's actually orthogonal.  Here's why: We don't listen to amps, we listen to systems, and how an amp works with our speakers is important in determining which will produce a sound we hear as closest to the original.  Granted thus far?

 

If yes: You are comparing two amps.  They have different phase behavior - let's say one is good at maintaining absolute or linear phase, while the other uses circuitry that operates in effect as a minimum phase filter.  (I don't even know whether such descriptions make sense in the context of amplifier operation and measurement.  Do they?)

 

If these descriptions of phase behavior in amps do have some validity: In your comparison of "frequencies and amplitudes" between two amps, is this an important variable, or is frequency response across the audible spectrum really what you are looking for?  Because for example a plus or minus .35dB variation in frequency response across the spectrum may not be audible to me, but perhaps the two amps might have different impacts on imaging and localization when combined with my speakers.

 

So that's what I'm after here: What tends to show up and be looked for as significant when comparing measurements of two amps, versus what may be significant when those two amps are placed into a system and music is played through that system.

 

Edit: By the way, I agree, as I mentioned in Bill's thread, that all the characteristics I'm talking about *can* be measured, and that in principle every characteristic important to what we hear can be.  So I'm not talking about measurability, but about what characteristics are highlighted by common measurements versus what may be significant in the context of a particular system.

[Jud]

3 minutes ago, pkane2001 said:

 

No, correlation is a well-defined mathematical procedure, not at all judgment-based. Something I've used to automatically match other types of signals, including the noisy 2D images in the frequency domain, as well periodic error of telescope tracking mounts. It's much more robust in the presence of large differences and noise than the nulling procedure you mentioned.

 

 

The nulling procedure seems pretty popular, which is why I mentioned it.

[Jud]

9 minutes ago, pkane2001 said:

And, if you know the characteristics of your speakers (that can also be measured), you can even predict with some degree of accuracy how well this amp will work in your system. I know this is not a popular thought among audiophiles, as it implies that you don't need to keep evaluating different components in your own home system 

 

I don't know that it's necessarily an unpopular thought.  I think positions can often tend to become more polarized on forums (whooda thunk, right?).  I'm happy to find that stuff out (as far as I can, not having the equipment or knowledge personally), and I'm guessing a lot of "audiophiles" feel the same.  But of course you can't discount the fun of listening.

 

I do something similar when buying cars.  I look at measurements that matter to me, but it's also nice to take a test drive.   

[Jud]

My thought is that Arthur has a lot of thoughts.

 

Even before I went to the link, I figured it was Arthur.  He’s kind of a quotable guy, if you like an opinionated style.

[Jud]

3 minutes ago, christopher3393 said:

 

I don'y find his style at all to my taste, but that is subjective.   Is his information accurate? Is he objective? Does he exercise good judgement? 

 

It’s a shotgun approach.  You can find stuff to agree or disagree with no matter what your opinion is.

[Jud]

5 minutes ago, christopher3393 said:

 

Jud, I may be wrong, but my impression is that you are being dismissive of the concerns I'm raising.

 

 

I’m being dismissive of taking Arthur very seriously.

[Jud]

10 hours ago, AJ Soundfield said:

Reality is full of traps for believers, because they are blissfully unaware of so many technical issues when they carry on their "hearing" sessions (aka "tests, listening, etc").

For example, take a speaker with highly erratic polar response:

 

(keep in mind the off axes curves are normalized to the (averaged curve above) on, so they are not as smooth as shown near zero axis).

What this means is that even the slightest head movement can result in a change is sound reaching the ears, in rather critical bands.

Unless a head vice is used, getting up even when listening to same amp, could sound different. Good luck getting up and actually inserting another!

 

 

Since listeners would presumably not have their heads in vices, would this change of sound with slight change of position not be audible?  And if inaudible, why problematic?

[Jud]

7 hours ago, AudioDoctor said:

Have you seen some of the shit posted here?  It's so ridiculous it deserves contempt and ridicule.

 

And to be clear, the OP was not about folks who occasionally come through with a sarcastic bon mot, who occasionally tell other folks they've got the wrong idea, or who when they see something actually dangerous being contemplated step in and caution people about it (as I've seen Speedskater and John Swenson do, to name two members I recall).  Rather it was about folks who seem contemptuous, dyspeptic, or both regarding the entire hobby and/or a large number of those who pursue it.

 

[Jud]

1 hour ago, pkane2001 said:

 

It wasn't @esidude that did the math wrong, it was the original article I quoted. And even if the speaker is 94dB sensitive (the author was explicit about 90dB/W/m), at 4m distance it still needs just about 0.006 watts to achieve 60dB. Still about three orders of magnitude higher than the claim made by the blog author of 1 millionth of a watt.

 

Further to my general admonition not to take the original author overly seriously, I think he wanted to get to a Really, Really Amazingly Small Number by whatever means necessary, in order to induce the reaction "Surely no one could ever have considered measuring that!  Aha!"  So while a quick look at the math, as you've done, is probably a good thing to keep people from getting too hung up on the specific Really, Really Amazingly Small Number that was named in the article, I'm not sure it's worth a whole lot of discussion.

[Jud]

6 hours ago, Sal1950 said:

 

Hogwash, you have no idea which is more accurate, your just making a big fat guess. LOL

 

I often see this on science blogs about evolution, for example.  (Other science blogs as well, but I've seen it most often regarding evolution.)  Someone with much lesser expertise won't understand at least some of what a person with greater expertise bases a statement on, therefore thinks it is merely an opinion like his own, and hence discounts and derides it.  So in this case a member who designs and builds audio circuits (check out his stuff at DIYAudio, folks ) and performs measurements of those circuits as a matter of course is ridiculed as "just making a big fat guess" by someone I would conjecture does none of that.

 

Now who knows, maybe in this case jabbr is just making a "big fat guess."  But my assumption would be to the contrary: That he understands what the circuitry in the two amps is doing, and since listening didn't show anything obviously wrong, he felt no need to perform measurements to determine the circuits were operating as designed.

[Jud]

11 hours ago, Sal1950 said:

It's not about taking pleasure in trashing someone, but showing everything is not without warts in the real world.

Being much more of a consumer advocate than has been shown to me in a long long time.

 

For me it isn't even so much about being a consumer advocate (though of course the consumers are the vast majority of readers - still, "car mags" or "home theater mags" don't often do consumer advocacy either), but about the content not being boringly uniform, issue after issue.  The reviews are highlighted content - they're usually the cover stories.  But there is no sense of anticipation seeing a review of a piece of equipment touted on the cover if you pretty well know what you'll find inside: "I liked it."

 

I don't know what the circulation figures say, but I personally stopped reading the reviews long ago and only glance occasionally at the mags, usually to see whether there's any music being reviewed that I'm not familiar with and looks interesting.  And sometimes the non-review articles have interesting content - one of them, by Michael Fremer the analog advocate of all people, got me into computer audio.  It's been a very, very long time since a friend said to me, "Have you seen the review of [X equipment] in [Y audio magazine]?"

[Jud]

4 minutes ago, jabbr said:

So anyways in theory there's no difference between theory and practice...

 

Blog of a guy working on computational complexity: https://lucatrevisan.wordpress.com/

 

See Simpsons quote at top.

[Jud]

30 minutes ago, Sal1950 said:

 

My usual pat answer here would be that since he didn't measure or state the use of bias controlled blind listening to reach his conclusions they can only be considered a guess.

But I will add in the this case that it is exactly his technical understanding of things that even more so will tend to color his subjective impressions.  The more he knows the more important it is for him to follow a path capable of removing his bias's as completely as possible.

 

So the more you know, the more biased you are toward the facts, and this is a problem?  

 

I’m not being completely serious - you still have to be aware your design may not perform as expected.  That’s of course why people test, measure, and listen.  Since very, very few designers are equipped with full research labs plus people to serve as blind testers plus people familiar with blind testing protocols and research to run the tests for them, much of the equipment you and I own may have survived all the tests and measurements, and then the people who listened to the prototypes that got that far may have been influenced by all those objective tests and measurements.  I don’t find myself overly much bothered by that.

[Jud]

5 minutes ago, semente said:

 

Of all the measured parameters you picked the only one where the Wilsons performed better...and probably the least important one.

You're not a professional audio reviewer by any chance, are you?

 

Ricardo has heard the Wilsons - Albrecht, have you heard the Revel Ultimas?  Perhaps you will like them.

[Jud]

5 hours ago, Sal1950 said:

Your opinions in this case are lost in the darkness created by lack of substantiated information.

 

Sorry, but wouldn’t it be just the opposite?  Wouldn’t his opinions be lost, if at all, in the light of all the objective, *substantiated* information he has about how the different ways the two circuits work?

 

And if his subjective opinions are overwhelmed by the objective facts, what is the problem?