Dynamic Wow and Flutter

[mtrycrafts]

Hi, as there are so many AES members here, I would be curious if someone would have any useful input....

As far as I understand this AES paper goes into detail about FM distortion artifacts that's been more or less known to be an issue for a long time, but never been addressed or never been measurable, but still audible to the human ear, this kind of distortion will be neglectable by those who only rely on the measuring equipment and say that the measurements present the only and whole truth.

I believe there's much more to amplifier technology and what makes a difference, than what's known so far.... If we close our eyes and say that we know everything we need to know audio technology will not get further but come to a standstill...

Much of the measurements that we have today was developed as a result of audible distortion properties that we were unable to explain and as such not measure, so new theories were developed and new measurement techniques and standards were developed. I'm no expert on this but it's what I read from a some respected amplifier designers, although.... I don't think this fact can be challenged.....

I think there's much more to amplifier technology and audibility of different distortion mechanisms than what we know today, but I can't prove anything.... but if we close our eyes we will not advance....

Now it's time for you guys to roll the sabers....

Someone is putting the cart before the horses, it seems.
Something is known, something is audible but cannot be measured, nor demonstrated is nonsense, period.
I want to see all those DBT results for audibility of these claims. Claims and no evidence is useless to making progress.

Doug Self has been at this for a long time as well, has a few JAES papers to his name, yet I have not seen anything about these distortions from him. Why?
Curl and Otala are known to promote woowoo. Jneutron has had numerous debates with Curl. Unfortunately Curl had no answers beyond well known designs, understood concepts, and such.

I am also wondering why this paper was not submitted to be a Journal paper if there is something to this notion after 30 years of knowing about it?
Oh, perhaps a conspiracy by AES, right?

 

[mtrycrafts]

This is extremely difficult to grasp.....
From what I heard Ron Quan spent considerable time with personal consultation... trying to explain this to world leading amp designers, and they're still having a hard time understanding what the heck this is.... so even for us to understand this, would be a long call.....

First step to get hold of the papers....

Well, if those "world leading amp designers" could not follow what Quan was trying to put across, I feel better and to me it looks like another attempt to find a non-existing problem.
But, hey, I don't qualify to be among those designers

 

[mtrycrafts]

To further expand this:

What happens if there is negligible FM/AM in the environment to begin with? If a tree falls and no one is around to hear it...

Then, the noise it makes is not my concern

 

[mtrycrafts]

...

Perhaps it explains some of the reason why you never hear the full scale of a symphonic orchestra at home, with your own equipment....
There's always a blurring and never full scale dynamics as in a concert hall

Actually it doesn't. Many other good reasons why you don't hear what you hear in an auditorium, especially with only two speakers, a small room not designed for such purpose, and a host of other good reasons.
If the goal is to hear what was in the live, one has to attend one in person.

 

[jinjuku]

Actually it doesn't. Many other good reasons why you don't hear what you hear in an auditorium, especially with only two speakers, a small room not designed for such purpose, and a host of other good reasons.
If the goal is to hear what was in the live, one has to attend one in person.

Season ticket holders to the Louisville Orchestra (but would rather it be the Cleveland Orchestra )

 

[jinjuku]

I think this is going along the lines of when Nordost hired a engineer that designed some sonar equipment.

 

[markw]

I don't see "wow and flutter" mentioned anywhere but, anyhow, what is this "FM distortion" supposed to sound like? Can it be identified with a DBT with normal source material and under normal listening conditions?

And, if it's inaudiable, not to mention unmeasurable, it sounds like a solution in search of a problem that exists to keep the wheels of commerce greased.

 

[Grador]

I'll start by trying to explain what I understand the test to have been. They were putting a pure tone sine wave and alternately square wave though an audio amp. They were then trying to induce the amplifier to cause a frequency shift in the output [FM modulation of the output] by varying the amplitude of the puretone [AM modulation of the input].

Where all of this falls apart is......well every single aspect. If you cannot measure a factor that you claim to be an audible distortion than how can you claim a correlation between a subjective experience and this "fm modulation" let alone causality. You might as well be saying "Fairy farts cause very unplesent audible distorting. We cannot tell when the fairys are farting, but you'll know they are when you hear the distortion."

Furthermore even if someone does prove that this FM distortion can be induced does not mean in the least that it would occur under normal operation conditions. Even if you can show that it will happen in program material you still need to determine how it effects the subjective experience.

I cannot possibly understand how people disagreeing with the upmost importance of curbing this FM distortion can be stated as a mindset that would halt advancement of audio equipment. Problem solving based upon actual data gets you much further than ghost hunting.

Finally, and for me one of the biggest red flags here. If the vast majority of leading people in a field "cannot understand" the "complexities" of something IN THEIR FIELD, that is usually not a good thing. It normally means that there is something dreadfully wrong with whatever they are reading that makes it more "incomprehensible" rather than "complicated".


But it is nice to know that we now have an explanation for phoenix effect distortion, as I'm pretty sure this is related.

 

[JerryLove]

I'd assert there are two standards for "measureability".

One, of course, is can I quantify it with an insturment.
The second, however, is simply "can I prove it exists".

The classic point of (blind) ABX testing is to separate truth from placebo.
If I can reliably tell X, then X is real; regardless of whether I've recorded and quantified it yet.

OTOH: I don't see any indication that we have a proven issue here. Indeed: it's seems counter-intuitive or obfuscated.

 

[Grador]

The classic point of (blind) ABX testing is to separate truth from placebo.
If I can reliably tell X, then X is real; regardless of whether I've recorded and quantified it yet..

This is most certainly true, but it is completely invalid to claim that something observed is caused by a certain immeasurable item. There are an infinite amount of immeasurable things you could claim caused the difference.

 

[Irvrobinson]

This is most certainly true, but it is completely invalid to claim that something observed is caused by a certain immeasurable item. There are an infinite amount of immeasurable things you could claim caused the difference.

In this context I completely agree, obviously, as one can read from my previous posts. However, your post just described exactly the conditions causing Einstein to propose the Cosmological Constant.

Don't get enthused, Haraldo, by this comparison to Einstein. Amplifier design and behavior is not like cosmology. Not even a little.

 

[3db]

Hi, as there are so many AES members here, I would be curious if someone would have any useful input....

As far as I understand this AES paper goes into detail about FM distortion artifacts that's been more or less known to be an issue for a long time, but never been addressed or never been measurable, but still audible to the human ear, this kind of distortion will be neglectable by those who only rely on the measuring equipment and say that the measurements present the only and whole truth.

I believe there's much more to amplifier technology and what makes a difference, than what's known so far.... If we close our eyes and say that we know everything we need to know audio technology will not get further but come to a standstill...

Much of the measurements that we have today was developed as a result of audible distortion properties that we were unable to explain and as such not measure, so new theories were developed and new measurement techniques and standards were developed. I'm no expert on this but it's what I read from a some respected amplifier designers, although.... I don't think this fact can be challenged.....

I think there's much more to amplifier technology and audibility of different distortion mechanisms than what we know today, but I can't prove anything.... but if we close our eyes we will not advance....

Now it's time for you guys to roll the sabers....

Roll our eyes my friend but never our sabers

Like Jerry said, FM modulation is very easy to measure and not beyond the realm of engineering or physics. I'm very leary of claims about a distortion that exists but cannot be measured. If it exists, it can be measured.

 

[haraldo]

You guys are amazing......

Dismissing an AES paper without even having a clue what is written there

 

[jinjuku]

You guys are amazing......

Dismissing an AES paper without even having a clue what is written there

I thought it was simply a poster session?

 

[jinjuku]

You guys are amazing......

Dismissing an AES paper without even having a clue what is written there

If you can tell the difference between a bunch of amps I'm personally not knocking you.

I still haven't heard an amp to date that would make me want to spend $10/20/30+ K on it. I also don't believe a competent, great sounding amp, need cost a bucket load.

I also believe that if you have a low impedence, low sensitivity, highly reactive speaker load you should pick with care the amp you get. In this scenario I do believe you could possibly hear differences.

I don't believe every amp designer has to design an amp to drive every possible speaker out there. That is simply a design choice by the engineers.

I'll see if I can get access to the paper that the Ron Quan referred to in his poster board session. Just got to ask the wife since she works at the University here. They have some Carte blanche access to some journals.

 

[Irvrobinson]

You guys are amazing......

Dismissing an AES paper without even having a clue what is written there

No, actually we're not, we asked to see the paper. What some of us *are* dismissing is:

- Any association between amplifier distortion and wow and flutter.
- Claims that reducing some sort of previously unidentified amplifier distortion will result in dramatic and audible improvement in amplifier performance.

And I'm personally dismissing your conclusion that because I'm not open-minded about newly discovered distortions making dramatic differences in amplifier performance that I'm somehow not open to innovation in general.

 

[haraldo]

No, actually we're not, we asked to see the paper. What some of us *are* dismissing is:

- Any association between amplifier distortion and wow and flutter.
- Claims that reducing some sort of previously unidentified amplifier distortion will result in dramatic and audible improvement in amplifier performance.

And I'm personally dismissing your conclusion that because I'm not open-minded about newly discovered distortions making dramatic differences in amplifier performance that I'm somehow not open to innovation in general.

You're so twisting the truth that it's unbelievable.....

First of all it's raised a question here if anybody knows anything about this
Second I ask if anybody knows anything about this
Third I asked if anybody knows how to get hold of this paper

I'm trying myself to get hold of the paper....

I'm not concluding anything, asking questions and want to find out things, as opposed to many of you here that knows the whole truth.... and unwilling to open your eyes and see things from another perspective.

But dealing with people like you is just a waste of time.
Consider me out of here, this is just madness and stupidity from you guys in here....

 

[Irvrobinson]

You're so twisting the truth that it's unbelievable.....

First of all it's raised a question here if anybody knows anything about this
Second I ask if anybody knows anything about this
Third I asked if anybody knows how to get hold of this paper

I'm trying myself to get hold of the paper....

I'm not concluding anything, asking questions and want to find out things, as opposed to many of you here that knows the whole truth.... and unwilling to open your eyes and see things from another perspective.

But dealing with people like you is just a waste of time.
Consider me out of here, this is just madness and stupidity from you guys in here....

You've got to be kidding. For example:

In Post #2 you say:

Dynamic wow and flutter exists in all amplification components and as I understand the leading designers of amplifiers are trying to understand what this is, nothing to do with "wow and flutter"

In Post #30 you say:

But it's there, in all Transistors, IC's opamps, you name it.....

Perhaps it explains some of the reason why you never hear the full scale of a symphonic orchestra at home, with your own equipment....
There's always a blurring and never full scale dynamics as in a concert hall

So in this thread you've asserted, without reading the paper yourself, that dynamic wow and flutter exists in all amplifier components, and then postulated that it might be why we can't realistically reproduce full-scale dynamics in our listening rooms. And you equate any skepticism about your remarks with close-mindedness? How quaint.

 

[mtrycrafts]

I think this is going along the lines of when Nordost hired a engineer that designed some sonar equipment.

Well, the company should promote listening to those cables in a submarine.

 

[mtrycrafts]

With this attitude I doubt there would ever be any progress in the field of Audio

Not much is needed in amps, lots in speakers, rooms, better mics, better recordings. Oh, yes, forgot about evolution of the human ears, especially as we get older.