The famous AB test between amplifiers

[Palladium]

If you want to challenge the scientific consensus you need to do better than to come up with flawed analogies. Your Chinese people have the benefit of understanding other Chinese people, they don't recognise different people by the sound of their voice only. There's also no evidence that supports your claim.

From what I know, Chinese placebophiles are decades behind the woo curve and somehow still believe they are breaking new unexplored ground.

 

[JiiPee]

So, a Chinese person can tell apart couple of Chinese people while they are discussing. That don't impress me much - I can tell apart two identical amplifiers from each other, when one of them is playing "Paranoid" by Black Sabbath, and the other one is playing "Ave Maria" by Maria Callas. (and my analogy makes just as much sense as END WAY's).

 

[JSmith]

There appears to be some serious mental gymnastics going on in this thread.


JSmith

 

[Pareto Pragmatic]

It's worth remembering SINAD contains elements of noise AND distortion. If all we cared about was distortion, 80 would probably be OK. We are much more sensitive to noise than we are to distortion, which is why a number like 96 may be referring to Signal to Noise Ratio (SNR), rather than distortion.

Thanks. Makes sense, though my thinking on the relative effects has never gone beyond "noise is everywhere so it is worse." And now that I think about it, 1% thd in room is listenable but 1% noise? I might have that if I plugged in to a mess of a multi room circuit with ungrounded knob and tube wiring, which I could, but won't. That dedicated circuit was worth every penny.

I often hear issues, then realize the dishwasher or air filter is on, or a problematic dimmer is on, in other rooms. That's noise for sure. OTOH, recently my speakers were slightly out of position, and THD was up ~0.4% (depending on frequency, but rough average +0.4%). Stll under 1% most places, but barely. The only effect was me thinking I had finally grown accustomed to my new set up and was not being wowed anymore. It certainly did not jump out as a problem.

 

[MaxwellsEq]

Thanks. Makes sense, though my thinking on the relative effects has never gone beyond "noise is everywhere so it is worse

Noise is a very interesting subject. Unlike distortion which can be derived from knowledge of the signal, noise has many interesting characteristics which have nothing to do with the signal itself. There's not one singular noise. But it worth remembering that most of us can't detect even high levels of distortion, but we can detect noise quite well. Also, depending on the noise type, we can detect (electronically) and also hear signals below the noise floor!

 

[mhardy6647]

maybe it is just me -- but I have a sense that the signal to noise ratio of this thread is rather low.

 

[END WAY]

I mean... not to mention... you know... the aliens.

All About UFO's

I'm more concerned he's being used by them as a useful idiot to promote their psy op. I mean, yeah, you could hire this guy, show him just enough to get him worked up, then cut him loose and let him "blow the whistle" all he wants. And watch the tax dollars roll in for programs you neither have...

www.audiosciencereview.com

I don't care at all about your sarcasm or MAB's
A moth or an elephant could hear some frequencies better than a human being, but obviously they do so because they have evolved in their environment for survival. I know that some people are not able to understand the concept and that is understandable.

 

[END WAY]

If you want to challenge the scientific consensus you need to do better than to come up with flawed analogies. Your Chinese people have the benefit of understanding other Chinese people, they don't recognise different people by the sound of their voice only. There's also no evidence that supports your claim.

And why do you consider it to be an erroneous analogy, if when you do A/B tests they are only to test perception? Under your logic of testing perception, what would be the correct analogy?

 

[Purité Audio]

Never really sold anything to a moth, perhaps if we stayed open later.
Keith

 

[Mart68]

Never really sold anything to a moth, perhaps if we stayed open later.
Keith

And take the shade off the lamp?

 

[END WAY]

A lot of people get offended when I say that listening to two twin children for the first time would be almost impossible for them to tell apart and for their mother the task is easy but we think it would be a bit different if we listened to two amplifiers in an A/B test for the first time.
This is just my analogy for this test.

Can I put a pair of speakers in my acoustically treated room, measure the frequency response and record it then take out all the acoustic treatment and diffusers and measure again and with a parametric EQ trace the frequency response it had before, the question is, will it sound the same to us even though there is a lot of reverberation?

 

[antcollinet]

And why do you consider it to be an erroneous analogy, if when you do A/B tests they are only to test perception? Under your logic of testing perception, what would be the correct analogy?

OK - here is the flaw in your analogies.

The fact that some people can distinguish differences between some sounds that others are not able to, or that people can learn to distinguish those differences, does not mean that ALL (measurable) differences between sounds can be distinguished by some people, or that anyone can learn to distinguish all differences.

Some measurable differences are so small that no human can distinguish them. They fall outside the capability of our auditory system to detect. This applies to the differences between most well performing/measuring amplifiers when operated within their limits. Usual caveats apply.

Why does the fact that a mother can hear the different sounds her twins make, when a stranger cannot, have anything to do with inaudible differences between amplifiers?

 

[END WAY]

OK - here is the flaw in your analogies.

The fact that some people can distinguish differences between some sounds that others are not able to, or that people can learn to distinguish those differences, does not mean that ALL (measurable) differences between sounds can be distinguished by some people, or that anyone can learn to distinguish all differences.

Some measurable differences are so small that no human can distinguish them. They fall outside the capability of our auditory system to detect. This applies to the differences between most well performing/measuring amplifiers when operated within their limits. Usual caveats apply.

Why does the fact that a mother can hear the different sounds her twins make, when a stranger cannot, have anything to do with inaudible differences between amplifiers?

What is for you an inaudible and an audible difference between amplifiers?

 

[Geert]

And why do you consider it to be an erroneous analogy, if when you do A/B tests they are only to test perception? Under your logic of testing perception, what would be the correct analogy?

We´re discussing the perception of sound. A valid analogy should not include other variables that help with identification, like the understanding of a specific language.

By the way, my neighbours are Chinese, as are some of my friends. I can easily identify them by the tone of their voice. And I don't understand a word of what they're saying.

 

[antcollinet]

What is for you an inaudible and an audible difference between amplifiers?

Here is the local well researched hypothesis:

Audibility thresholds of amp and DAC measurements

Introduction A recurring theme on ASR is whether or not the various measured qualities of the devices are audible. In this post, I'll present some clear and visual thresholds for when those imperfections can be considered a potentially audible concern. I will not explain the basics of amp/DAC...

www.audiosciencereview.com

Bear in mind the limits will be much lower than even the lenient limits when listening with speakers (where the speakers will typically be the weak link for distortion). They will also be much lower for the vast majority of people who are not teenagers with perfect hearing.

 

[END WAY]

We´re discussing the perception of sound. A valid analogy should not include other variables that help with identification, like the understanding of a specific language.

By the way, my neighbours are Chinese, as are some of my friends. I can easily identify them by the tone of their voice. And I don't understand a word of what they're saying.

A lot of people get offended when I say that listening to two twin children for the first time would be almost impossible for them to tell apart and for their mother the task is easy but we think it would be a bit different if we listened to two amplifiers in an A/B test for the first time.
This is just my analogy for this test.
In this case we are not dealing with another language, take it as if they speak their native language and see if you can find differences the first time you hear it.

 

[antcollinet]

A lot of people get offended when I say that listening to two twin children for the first time would be almost impossible for them to tell apart and for their mother the task is easy but we think it would be a bit different if we listened to two amplifiers in an A/B test for the first time.
This is just my analogy for this test.
In this case we are not dealing with another language, take it as if they speak their native language and see if you can find differences the first time you hear it.

Do you think the mother is using ONLY the sound of the voice. Or are there a million other cues she can tune in to? That is - as pointed out by @Geert - the other flaw in your analogy.

 

[NTK]

A lot of people get offended when I say that listening to two twin children for the first time would be almost impossible for them to tell apart and for their mother the task is easy but we think it would be a bit different if we listened to two amplifiers in an A/B test for the first time.
This is just my analogy for this test.

What the people did was to learn to recognize what the "tells" are.

Seasoned audio researchers also recognize what the most revealing characteristics are, and came up with methods to train listeners. See below for examples:

How to Listen: A Course on How to Critically Evaluate the Quality of Recorded and Reproduced Sound

Next month, I will be giving a one day course on How to Listen at the 2011 ALMA Winter Symposium in Las Vegas,held Jan. 4th and 5th, just...

seanolive.blogspot.com

Audio Production and Critical Listening: Technical Ear Training

Audio Production and Critical Listening: Technical Ear Training, Second Edition develops your critical and expert listening skills, enabling you to listen to audio like an award-winning engineer. Featuring an accessible writing style, this new edition includes information on objective...

www.routledge.com

Studies have showed that trained and untrained listeners will generally come to the same conclusions -- they produce the same orders of good-to-bad rankings of the devices they tested. The trained listeners will, however, be more consistent* in their rankings and faster in arriving at their judgements. It is also found out that people with hearing damages are usually much more inconsistent in their ratings.

* Note that the tests are double blind. Consistency can be evaluated, for example, by testing the testers with the same devices but altering their designations and test sequence (for example speaker A becomes speaker C, D becomes A, etc.)

Can I put a pair of speakers in my acoustically treated room, measure the frequency response and record it then take out all the acoustic treatment and diffusers and measure again and with a parametric EQ trace the frequency response it had before, the question is, will it sound the same to us even though there is a lot of reverberation?

No. The speakers will not sound the same in different rooms or different room conditions. Human hearing separate the direct sound from the later arriving reflected sounds, which are highly dependent on room conditions/treatments. That also means the steady state room frequency response curves cannot tell the whole story.

But a good speaker will sound better than a bad speaker in good rooms and in bad rooms. Just like a good musical instrument will sound better than a bad/mistuned musical instrument in good concert halls and in bad concert halls.

 

[END WAY]

That's what I mean, the mother can hear these differences because she is used to it, a stranger can't.
In a/b tests something similar happens, when a stranger listens to the two amplifiers for the first time, he or she will most likely find no differences.

Do you think the mother is using ONLY the sound of the voice. Or are there a million other cues she can tune in to? That is - as pointed out by @Geert - the other flaw in your analogy.

 

[antcollinet]

That's what I mean, the mother can hear these differences

I'm not talking about things she can hear - or at least not about the things that are defined by identical genetics. There are a million other verbal and non verbal/auditory clues she will be picking up on subconsciously also.

It is a meaningless analogy. It simply doesn't apply to a blind test where ONLY the tonality is available.