Toward a Theory To Increase Mutual Understanding and Predictability

[Folsom]

Can't agree, Folsom - morricab is expressing an opinion that I agree with.

It all boils down to psychoacoustics & the mechanisms by which auditory processing works.
Room reflections are distortions in so far as they are not part of the original recorded sound but we are accommodated to them from our experience of how acoustic spaces behave & our auditory processing is able to analyse & separate these reflection distortions into a separate acoustic stream. We are therefore able to focus on other aspects of the soundstream & virtually ignore room reflections. Exactly the same as we do when listening to & following a single conversation in a room full of babbling voices - we are analysing the nerve pulse signals arising from ALL the vibrations hitting the eardrum & grouping a certain subset of vibrations into the stream that represents the conversation we are trying to follow. By focussing on this conversation we are consciously oblivious to the babble in the room unless it intrudes our consciousness & it does sometimes. But even though we are not conscious of this babble it is affecting our listening - we are straining more than normal & given a chance we will try to avoid the additional energy necessary to do this.

But what happens if we eliminate these room reflections altogether by listening in an anechoic chamber? The most often expressed opinion is that it sounds weird & unnatural i.e our auditory processing recognises this as a sound not encountered in nature. Again people do not want to stay in this environment for too long.

The lesson seems to be that our auditory processing system is comfortable with a level of distortion that we have been exposed to in our contact with the world of sound & we know we are comfortable with.

Again all instruments have amplitude & frequency modulations in their sound envelopes as a result of the non-linear aspects of these instruments - it's what gives them their timbre. I believe it's the accurate reproduction of these fine FM & AM signals (low level signal linearity) that is at the heart of realism & immersion. These low level signals have to be preserved in their journey through the audio electronics on the way to the speaker. it's what can often differentiate one instrument among a number of the same between one type of Unnaturally high levels or distortion that

This is exactly what morricab is saying & which I agree with - it's our auditory processing mechanisms that have to be satisfied if we want believability & envelopment (immersion) from our audio playback.

Accuracy is a wasteful goal, IMO - firstly we have failed many times in the past with measures of accuracy in audio & I have no doubt we are currently still off the mark. Secondly, input to output is not 100% accurate - the judgement of 'accuracy' is premised on the errors measured being below audibility so we are already talking about a qualified accuracy. Now there are a lot of holes in this qualification - are the measured errors fully characterising the playback system in all its performance, including it's behaviour with a dynamic, non-repeating, chaotic signal such as music? Can this be truthfully guaranteed?

At this juncture, in audio playback development, we have peeled off enough layers of the onion that we are now at a crossroads - we know that the illusion of realism & immersion/envelopment are possible - a lot of us (I won't say all) have heard it or heard hints of it - do we endeavour to achieve this in a stable way by improving 'accuracy' even though it is considered by many to be 'perceptually accurate', anyway? There's a disconnect here, I believe.

As morricab eloquently says - much better to ignore those distortions that are in the blind spot of our perception & expend our energy on those aspects that have more significance (even though they may well be considered

But your example is quantifiable to nothing more than "distortions" and when I ask how do I correct them, you give me your own personal idea of what you believe works. morricab's idea of distortions is from the electronics, not the acoustics. This amounts to piles of gibberish.

Why don't you say that you believe reflections are a problem for immersion, and you believe that it's integral to the #1 experience to reduce them. From a technical standpoint they aren't necessarily distorting the signal, but what they do for sure is create multiple arrivals of the same sound at different times. We know this because you can calculate it. We don't need to know that, but saying reflections are a problem for immersion is more useful than claiming the ever-god distortion is the problem.

 

[amirm]

And I'm sure that research proves that I am quite wrong about a lot of things, but you are misstating my position.

Research knows you a heck of a lot better than you know you! This is the point I made first in this post. We are not in disagreements with respect to what we hear and judgement of its fidelity. We are in huge disagreement when we attempt to explain it using who knows what reference and data point. Hence my objection to your post about your system and your friends both being about accuracy. Take away the attempts at explanation and the ultimate truth falls out. Which is a great thing really....

 

[jkeny]

But your example is quantifiable to nothing more than "distortions" and when I ask how do I correct them, you give me your own personal idea of what you believe works. morricab's idea of distortions is from the electronics, not the acoustics. This amounts to piles of gibberish.

The reason I introduced room reflections as 'distortions' was to show that our auditory system works by analysing the neurological signals into groupings that it perceives as auditory streams. We do this constantly & automatically - we can therefore disentangle the room reflections from the actual sound objects in the soundfield. Remember this is all down to some form of analysis that involves a continual pattern matching & comparison to our internally stored representations for how auditory objects work in the natural world. Morricab's point, which I agree with is that our non-linear electronics systems can more easily produce signal patterns that our perception senses are unnatural & we will be taken out of any possibility of immersion by such disturbance in the signal. I was just giving an example of an acoustic distortion in room reflections which, yes we can easily measure but which is easily ignored by our perceptual system.

If you start with auditory perception as the core of what we hear & work out from there, rather than the other way from the signal as the core, I think what I'm saying might become clearer?

Let's not jump to cries of gibberish & try more to understand the other person's POV

Why don't you say that you believe reflections are a problem for immersion, and you believe that it's integral to the #1 experience to reduce them. From a technical standpoint they aren't necessarily distorting the signal, but what they do for sure is create multiple arrivals of the same sound at different times. We know this because you can calculate it. We don't need to know that, but saying reflections are a problem for immersion is more useful than claiming the ever-god distortion is the problem.

Ah, you seem to miss the point of the examples - in fact I'm not saying room reflections "are a problem for immersion" - in fact, it's the exact opposite - room reflections may be necessary for immersion, for creating the illusion of believability? Why. Because we mostly only encounter sound in a reverberant environment - note how listening in an anechoic chamber feels unnatural & immersion may not be possible.

 

[cjfrbw]

I know that the BAAS group a few years ago had a field trip to famous Fantasy Studios. They listened to an ensemble group live as it was being recorded. Nobody said the rough mixdown sounded like the original witnessed performance, and a few said some of the instrument placements were entirely different on the recording vs. what they saw.

 

[PeterA]

Research knows you a heck of a lot better than you know you! This is the point I made first in this post. We are not in disagreements with respect to what we hear and judgement of its fidelity. We are in huge disagreement when we attempt to explain it using who knows what reference and data point. Hence my objection to your post about your system and your friends both being about accuracy. Take away the attempts at explanation and the ultimate truth falls out. Which is a great thing really....

Amir, I have already been convinced that "accuracy" is the wrong way to describe my goal of having the sound of my system remind me of what I think live, un-amplified instruments sound like. I've got that. My friend and I seem to be after the same thing. For the sake of discussion, we are working within the premise of Ron's original post. My friend and I both use live music as a reference and want our systems to sound like that. Whether mine actually does or not is based on my subjective impressions based on my memory of what instruments sound like. Nothing more. My reference or data point is not "who knows what" as you suggest. My reference is live music, as should be clear by now. I am certainly not asking you to agree with this approach. You can do whatever you want, Amir. I do not know if my friend still refers to his audio goal as "accuracy". I have not asked him lately.

 

[morricab]

morricab, you must understand what you're saying, when applied to electronics, is mostly gibberish. It's not because it's invalid, it's because it's not describing it well enough. Your idea of ignoring/masking distortion makes little sense. What you're probably describing if often the differences in recording and engineering choices, and haven't realized it.

SET's of the past generated more distortion from the tubes, and the resistors they used. Half to 90% of it was just from how the tubes ran, which are the same tubes used today. Designers today may or may not chose to scale down the distortion that tubes are inclined towards. Tubes are however very linear, more so than solid state tends to be, which may give them qualities you're describing.

If you and I were to sit in front of a stereo and play music, I bet we could pick similar parts of tracks out that were of interest. But you'd describe something very different from what I would about it. The difference is I could walk up to it, do some soldering changes, and change the aspect we're talking about by knowing what causes it.

You touched on noise, and that's a huge problem. But even a low noise system doesn't magically turn the sound into what people may want.

What I am saying about electronics is anything but gibberish. It is clear that different electronic circuit topologies create different distortion patterns. It is also clear that some of these are better tolerated by the human ear/brain than others. Read Geddes distortion papers and the Cheever thesis for why this is likely to be true. Jean Hiraga noticed this as well in the 1970s that a monotonic distortion pattern was a preferrable pattern sonically. That means a regular order of even and odd harmonics in an exponential decay. This is what Cheever showed to be the same pattern as what the human ear/brain self-generates. He argues that if the electronics mimic that pattern, at ALL SPL, then it will sound essentially pure becuase it will be perfectly masked.

If "my" idea of ignoring/masking makes little sense to you it is becuase you have been ignoring about 60+ years worth of research into the area of human hearing. Suffice to say it was not my idea but has come out of research and it is a real phenomena. It is well known that the harmonics closest to the fundamental are masked and preferrentially in the direction of the higher(overtone) not lower (sub) harmonics and that the degree of masking is SPL dependent. So, what I am describing has absolutely nothing to do with the recording and engineering choices...I am talking about something much more fundamental and you clearly didn't realize it.

Yes, most of the tubes are the same but I think the power supplies are far more stable and this reduces the distortion. Tubes are more linear than any transistor, which is why no feedback as a concept can work with tubes and is dubious at best with SS. However, a single ended MOSFET, running Class A, should only produce simple and low order harmonics. This makes it potentially a good output device for a single ended Class A amplifier without feedback. I have had such an amp and while it did not sound exactly like a normal SET it was still quite good and had better grip on the bass than most (but not all) SETs.

I never said noise control did a magical anything. You were the one banging on about noise. I simply agreed with you that it is important to control. I run my sources off of a Monarchy Audio Power regenerator for just that reason...it reduces noise and increases transparency and resolution of my sources by a significant margin.

 

[morricab]

I believe you took one extra leap. While it's not easy or reasonable for all of us to be measuring everything, the topic isn't actually about how we achieve the steps per se.

What's important to Ron, and I believe is important, is how we're talking about these aspects. Now - not that I want to provoke morricab more but - as an example if you describe everything as a "distortion" or "linear and not-linear" it's not very useful to people with different goals because it's only in your frame of reference as towards what you think those attributes are. Just like how for Peter, his goal is to accurately represent a live performance but that can easily be shortened to accurate which has different meanings for someone with a #2 outlook. (Aka the mastering engineer that thinks his work is art)

What do I suggest people do? Listen to equipment for what they like. But I believe Ron was right to bring up the topic. It's on topic with his general postilation that we should use less hyperbole, and talk about what we're hearing. It'll help everyone describe what is going on much better so that our text format of sharing information on the forum will be more pertinent to understanding; which helps a lot when people are looking for equipment for example.

I'm starting to believe this may have to evolve into an interesting scenario, like having a group gathering where we discuss things as we listen and gain knowledge on what is what. And after that "clinic" the people whom attended could help others. The event may have to last for days, and would require an assortment of gear that were picked for very specific reasons. Well, it sounds nice in my head to propose something of this nature, as far as happening that may not be as easy. At least it'd be easier than our on going discussion here.

You are pretending that all humans have different ways of processing auditory signals and that just isn't the case. While preferences from years of conditioning will creep into any decision, the basics of how we hear and how the brain processes and masks information is large consistent from human to human. That means it should be possible to develop models that work for MOST of humanity and lead to a convergence of what would be, from an auditory POV, accurate and therefore lifelike sound. Linearity and non-linearity of signals plays a big role in this whether you like it or not. A model that describes how most people would prefer to have the sound is a useful model for those who are not just playing aroudn with 3).

I believe people will be best served at point 3 if they have achieved point 1. The most realistic should be the most pleasing to most people...not all...some people literally listen to noise, for example, but to most who listen to natural instruments in natural spaces.

 

[morricab]

But your example is quantifiable to nothing more than "distortions" and when I ask how do I correct them, you give me your own personal idea of what you believe works. morricab's idea of distortions is from the electronics, not the acoustics. This amounts to piles of gibberish.

Why don't you say that you believe reflections are a problem for immersion, and you believe that it's integral to the #1 experience to reduce them. From a technical standpoint they aren't necessarily distorting the signal, but what they do for sure is create multiple arrivals of the same sound at different times. We know this because you can calculate it. We don't need to know that, but saying reflections are a problem for immersion is more useful than claiming the ever-god distortion is the problem.

Distortions from the acoustics can also affect the realism but not usually in such a destructive way as the electronics. As I said, I can get far more beliveable sound from a "mediocre" pair of speakers and great electronics than I can from the other way around...I have demonstrated this a number of times and it is logical once you understand the psychoacoustics. Electromechanical systems are still physical moving sysetems that our evolution can cope with the distortions they make in a way it cannot with electronic distortions. The patterns are different. A loudspeaker will produce predominantly 2nd and 3rd order harmonic distortion, which is largely masked. A bigger problem with speakers is breakup of drivers and cabinet resonances, which are not directly correlated with the signal. They are excited by the signal but they are not harmonics of the signal. These are the main colorants of loudspeakers and if they are bad enough can destroy believability as well.

 

[morricab]

The reason I introduced room reflections as 'distortions' was to show that our auditory system works by analysing the neurological signals into groupings that it perceives as auditory streams. We do this constantly & automatically - we can therefore disentangle the room reflections from the actual sound objects in the soundfield. Remember this is all down to some form of analysis that involves a continual pattern matching & comparison to our internally stored representations for how auditory objects work in the natural world. Morricab's point, which I agree with is that our non-linear electronics systems can more easily produce signal patterns that our perception senses are unnatural & we will be taken out of any possibility of immersion by such disturbance in the signal. I was just giving an example of an acoustic distortion in room reflections which, yes we can easily measure but which is easily ignored by our perceptual system.

If you start with auditory perception as the core of what we hear & work out from there, rather than the other way from the signal as the core, I think what I'm saying might become clearer?

Let's not jump to cries of gibberish & try more to understand the other person's POV


Ah, you seem to miss the point of the examples - in fact I'm not saying room reflections "are a problem for immersion" - in fact, it's the exact opposite - room reflections may be necessary for immersion, for creating the illusion of believability? Why. Because we mostly only encounter sound in a reverberant environment - note how listening in an anechoic chamber feels unnatural & immersion may not be possible.

Well put.

 

[LL21]

lots to catch up on reading! thanks to the gents who have posted in the last 12 hours...

 

[Folsom]

The reason I introduced room reflections as 'distortions' was to show that our auditory system works by analysing the neurological signals into groupings that it perceives as auditory streams. We do this constantly & automatically - we can therefore disentangle the room reflections from the actual sound objects in the soundfield. Remember this is all down to some form of analysis that involves a continual pattern matching & comparison to our internally stored representations for how auditory objects work in the natural world. Morricab's point, which I agree with is that our non-linear electronics systems can more easily produce signal patterns that our perception senses are unnatural & we will be taken out of any possibility of immersion by such disturbance in the signal. I was just giving an example of an acoustic distortion in room reflections which, yes we can easily measure but which is easily ignored by our perceptual system.

If you start with auditory perception as the core of what we hear & work out from there, rather than the other way from the signal as the core, I think what I'm saying might become clearer?

Let's not jump to cries of gibberish & try more to understand the other person's POV


Ah, you seem to miss the point of the examples - in fact I'm not saying room reflections "are a problem for immersion" - in fact, it's the exact opposite - room reflections may be necessary for immersion, for creating the illusion of believability? Why. Because we mostly only encounter sound in a reverberant environment - note how listening in an anechoic chamber feels unnatural & immersion may not be possible.

I think a key might be to not leave the word "distortion" on it's own. A room gives you a distorted perception of what the speaker is producing due to reflections, but are not necessarily related to distortion of the signal.

But I have to say one of the biggest problems is that we accept everyone's "POV" which includes their own specialized language. I believe everyone has a valid POV, but the problem we're really talking about is that we need common terms.

BTW the most believable a stereo sounds to me, is ALWAYS from the next room. All of the signals of soundstage, placement, etc, are left in the room, so I can't be fooled by them, and I don't have reflections fighting how accurate the timing is so the music appears more linear. This is for me is a way to judge a stereo's qualities in many respects.

You'd probably be best off cutting off a lot of the higher frequencies in order to create a more live experience in a room, but you'll lose a lot of things like 3D depth etc.

What I am saying about electronics is anything but gibberish. It is clear that different electronic circuit topologies create different distortion patterns. It is also clear that some of these are better tolerated by the human ear/brain than others. Read Geddes distortion papers and the Cheever thesis for why this is likely to be true. Jean Hiraga noticed this as well in the 1970s that a monotonic distortion pattern was a preferrable pattern sonically. That means a regular order of even and odd harmonics in an exponential decay. This is what Cheever showed to be the same pattern as what the human ear/brain self-generates. He argues that if the electronics mimic that pattern, at ALL SPL, then it will sound essentially pure becuase it will be perfectly masked.

If "my" idea of ignoring/masking makes little sense to you it is becuase you have been ignoring about 60+ years worth of research into the area of human hearing. Suffice to say it was not my idea but has come out of research and it is a real phenomena. It is well known that the harmonics closest to the fundamental are masked and preferrentially in the direction of the higher(overtone) not lower (sub) harmonics and that the degree of masking is SPL dependent. So, what I am describing has absolutely nothing to do with the recording and engineering choices...I am talking about something much more fundamental and you clearly didn't realize it.

Yes, most of the tubes are the same but I think the power supplies are far more stable and this reduces the distortion. Tubes are more linear than any transistor, which is why no feedback as a concept can work with tubes and is dubious at best with SS. However, a single ended MOSFET, running Class A, should only produce simple and low order harmonics. This makes it potentially a good output device for a single ended Class A amplifier without feedback. I have had such an amp and while it did not sound exactly like a normal SET it was still quite good and had better grip on the bass than most (but not all) SETs.

I never said noise control did a magical anything. You were the one banging on about noise. I simply agreed with you that it is important to control. I run my sources off of a Monarchy Audio Power regenerator for just that reason...it reduces noise and increases transparency and resolution of my sources by a significant margin.

First off Geddes knows very little about electronics, despite his great knowledge of speakers. He's proven this over and over and over and over... on the DIYaudio forum. In fact he doesn't even like to post because of problems as such (funny because he knows speakers very well). But you're not wrong that different types of amplifiers have different types of distortion, and people have different preferences. The funny thing is this is ancient information that everyone in the industry is very well aware of so it's not really of an interest. If you're only into companies that openly admit dumping preferred distortion into their devices, that's cool. But really there isn't a discussion here sense no one has ever come to agreement trying to use monotonic distortion was worth the effort given that people respond just as well to anything 3rd harmonic or lower, and most of it is vanishing low these days. It's not irrelevant, it's just not a point of discussion for anything but history.

So I'm actually back to how what you've described, in the way you did, isn't what I'd call useful. Sure, low order harmonics aren't particularly noticeable, or "masked" when they're low, so? And I would refute your assertion that sterile electronics have high order harmonic problems (since it's almost impossible to design audiophile/studio grade stuff and not know about harmonics). Generally most of the time people think things are sterile that don't have considerable amounts of low order harmonic distortion. It's not like it's hard to read when someone uses a lot of 2nd order, as the sound is rather warm, so we can all identify it pretty easily these days.

However, I think you'd make a great writer for manufacturers that would like to make big deals out of common things (most do, because audiophiles want something to read).

 

[Folsom]

You are pretending that all humans have different ways of processing auditory signals and that just isn't the case. While preferences from years of conditioning will creep into any decision, the basics of how we hear and how the brain processes and masks information is large consistent from human to human. That means it should be possible to develop models that work for MOST of humanity and lead to a convergence of what would be, from an auditory POV, accurate and therefore lifelike sound. Linearity and non-linearity of signals plays a big role in this whether you like it or not. A model that describes how most people would prefer to have the sound is a useful model for those who are not just playing aroudn with 3).

No, I'm not. I very specifically stated we hear the same things but describe them very differently. That's the problem. That's the premise of most of what I've written in this forum topic. I greatly wish for a convergence of common language.

 

[morricab]

I think a key might be to not leave the word "distortion" on it's own. A room gives you a distorted perception of what the speaker is producing due to reflections, but are not necessarily related to distortion of the signal.

But I have to say one of the biggest problems is that we accept everyone's "POV" which includes their own specialized language. I believe everyone has a valid POV, but the problem we're really talking about is that we need common terms.

BTW the most believable a stereo sounds to me, is ALWAYS from the next room. All of the signals of soundstage, placement, etc, are left in the room, so I can't be fooled by them, and I don't have reflections fighting how accurate the timing is so the music appears more linear. This is for me is a way to judge a stereo's qualities in many respects.

You'd probably be best off cutting off a lot of the higher frequencies in order to create a more live experience in a room, but you'll lose a lot of things like 3D depth etc.




First off Geddes knows very little about electronics, despite his great knowledge of speakers. He's proven this over and over and over and over... on the DIYaudio forum. In fact he doesn't even like to post because of problems as such (funny because he knows speakers very well). But you're not wrong that different types of amplifiers have different types of distortion, and people have different preferences. The funny thing is this is ancient information that everyone in the industry is very well aware of so it's not really of an interest. If you're only into companies that openly admit dumping preferred distortion into their devices, that's cool. But really there isn't a discussion here sense no one has ever come to agreement trying to use monotonic distortion was worth the effort given that people respond just as well to anything 3rd harmonic or lower, and most of it is vanishing low these days. It's not irrelevant, it's just not a point of discussion for anything but history.

So I'm actually back to how what you've described, in the way you did, isn't what I'd call useful. Sure, low order harmonics aren't particularly noticeable, or "masked" when they're low, so? And I would refute your assertion that sterile electronics have high order harmonic problems (since it's almost impossible to design audiophile/studio grade stuff and not know about harmonics). Generally most of the time people think things are sterile that don't have considerable amounts of low order harmonic distortion. It's not like it's hard to read when someone uses a lot of 2nd order, as the sound is rather warm, so we can all identify it pretty easily these days.

However, I think you'd make a great writer for manufacturers that would like to make big deals out of common things (most do, because audiophiles want something to read).

It is not relevant whether Geddes knows a lot about electronics or not...that doesn't invalidate the exploration he did into distortion mechanisms and the audibility. Given that both Geddes and Cheever's work is in the early 2000s indicates that this is anything but a dead academic topic. It is relevant for the NOW because many so-called high end amps fall down here and are not nearly as great sounding as they have been hyped to be and I think this is the reason why...they do not even attempt to have a natural distortion pattern, instead relying on "best engineering practice" to get low distortion and damn the pattern.

That is just it, the preference will tilt towards the patterns that are most natural once other bias is eliminated (price, prestige, indoctrination etc.). Humans, by in large, will gravitate towards a convergencs point but indoctrination is strong as is bling and price...and advice.

You are wrong about strerile electronics and high order harmonic distortion. Go look at measurements at Soundstage and Stereophile. You will see clearly that most amps still generate significant amounts of high order harmonics. What I find funny is that you are ignoring the obvious that even ultralow distortion amps all sound different. To be sure, they sound more similar to each other than to a SET or Class A PP triode amp but different nonetheless. We have had ultralow distortion amps since the 1970s but they didn't really sound very good now did they?

Clearly Mr. Lamm disagrees with you as his amps are designed just in the way you say no one bothers to do. Mr. Pass in his white paper in 2008 (I think) basically says similar things about distortion.

Define a lot of 2nd order? Most good SETs, when used welll below their limits, will have only a couple tenths of a %, which is inaudible according to most studies. When pushed they get up to the few % but at SPL levels that will generally make this inaudible as well.

 

[morricab]

No, I'm not. I very specifically stated we hear the same things but describe them very differently. That's the problem. That's the premise of most of what I've written in this forum topic. I greatly wish for a convergence of common language.

What would you have then for a common language to describe what we hear?

 

[Folsom]

What would you have then for a common language to describe what we hear?

Common language for given sounds. That's why I was saying the idea of doing events where people listen to distinct things from different types of gear, so they could come to agreement on concise language for sound. It would be important to well represent the electronics side. For example using different amps that have different levels of harmonic distortion as part of the exercises.

 

[Folsom]

It is not relevant whether Geddes knows a lot about electronics or not...that doesn't invalidate the exploration he did into distortion mechanisms and the audibility. Given that both Geddes and Cheever's work is in the early 2000s indicates that this is anything but a dead academic topic. It is relevant for the NOW because many so-called high end amps fall down here and are not nearly as great sounding as they have been hyped to be and I think this is the reason why...they do not even attempt to have a natural distortion pattern, instead relying on "best engineering practice" to get low distortion and damn the pattern.

That is just it, the preference will tilt towards the patterns that are most natural once other bias is eliminated (price, prestige, indoctrination etc.). Humans, by in large, will gravitate towards a convergencs point but indoctrination is strong as is bling and price...and advice.

You are wrong about strerile electronics and high order harmonic distortion. Go look at measurements at Soundstage and Stereophile. You will see clearly that most amps still generate significant amounts of high order harmonics. What I find funny is that you are ignoring the obvious that even ultralow distortion amps all sound different. To be sure, they sound more similar to each other than to a SET or Class A PP triode amp but different nonetheless. We have had ultralow distortion amps since the 1970s but they didn't really sound very good now did they?

Clearly Mr. Lamm disagrees with you as his amps are designed just in the way you say no one bothers to do. Mr. Pass in his white paper in 2008 (I think) basically says similar things about distortion.

Define a lot of 2nd order? Most good SETs, when used welll below their limits, will have only a couple tenths of a %, which is inaudible according to most studies. When pushed they get up to the few % but at SPL levels that will generally make this inaudible as well.

You're all over the place.

Early 2000's? That is old enough to me. And please reference me to all these amps that "damn" the harmonics. You believe distortion is what separates amplifiers, I think most designers on the planet would sell parts of their body for the answer to be that easy. If it was that easy all amps would probably be good. It's not exactly hard, or new, to model the types of harmonic distortions topologies will produce.

At what point have I said amplifiers don't sound different, despite their similar distortion measurements? I propose reasons for that all the time, and say that distortion figures are almost meaningless for how good something will be since it's subjective and shows pretty much no correlation. In my thoughts on #2 I expressly said some amps do it better, and others worse, in attaining the goal.

I just said exactly that designers aim for 3rd harmonic or lower. I could not have stated that anymore clearly. So how am I in any disagreement with Lamm or Pass? Antiquated conversation.

BTW the first thing about harmonics that google brings up is Dartzeel's big monoblocks where Atkins says despite the higher order harmonics than you'd expect, they don't appear to play any role.

This isn't on topic, too much. We're talking about your beliefs instead of choices of words for descriptions that explain our goals.

 

[853guy]

No, I'm not. I very specifically stated we hear the same things but describe them very differently. That's the problem. That's the premise of most of what I've written in this forum topic. I greatly wish for a convergence of common language.

Hi Folsom,

I think the wish of convergence is marred by the reality that A) many of us fundamentally disagree about the purpose of the mechanism; B) many of us fundamentally disagree about the nature of the art form; and C) we reach the limits of language when we attempt to describe another art form where those two methods of communication - one being language, the other being music - are neurobiologically distinct processes that do not share common overlap.

Given that music is only ever a perceptual phenomena, I think we need to move beyond the status quo this thread - and millions of others - risks returning to, in the manner the Bible would describe as a dog returning to its own vomit.

The problem is that currently we have this:




Personally, I think a way forward must involve this:




My personal belief is that until we have a greater understanding of how and why the brain processes music separate not only from language but also from sound, we will fall into a dialectic between subjective and objective observations in which the problem of language acts an impediment to understanding, as the endless debates this hobby has continually occupied itself with have clearly demonstrated.

Peace and love,

853guy

 

[Folsom]

Except you're overlooking the physical element. If I can turn or dial or solder in a different part, and change the exact same thing we're both hearing... The definition is made.

What I see is more ego in the path, with wishes for the realm of audiophilism to be one's personal projection that makes them feel good as they take a form of ownership, and desire to keep a mythical element to the hobby.

 

[morricab]

You're all over the place.

Early 2000's? That is old enough to me. And please reference me to all these amps that "damn" the harmonics. You believe distortion is what separates amplifiers, I think most designers on the planet would sell parts of their body for the answer to be that easy. If it was that easy all amps would probably be good. It's not exactly hard, or new, to model the types of harmonic distortions topologies will produce.

At what point have I said amplifiers don't sound different, despite their similar distortion measurements? I propose reasons for that all the time, and say that distortion figures are almost meaningless for how good something will be since it's subjective and shows pretty much no correlation. In my thoughts on #2 I expressly said some amps do it better, and others worse, in attaining the goal.

I just said exactly that designers aim for 3rd harmonic or lower. I could not have stated that anymore clearly. So how am I in any disagreement with Lamm or Pass? Antiquated conversation.

BTW the first thing about harmonics that google brings up is Dartzeel's big monoblocks where Atkins says despite the higher order harmonics than you'd expect, they don't appear to play any role.

This isn't on topic, too much. We're talking about your beliefs instead of choices of words for descriptions that explain our goals.

Sorry, early 2000s is not old for scientific research...it is highly relevant to today's designs. Not much has changed in SS or tube design in the last 20+ years, despite weekly claims for "new" and "amazing" breakthroughs by the audio press. There are plenty of examples...just go look for yourself...I am not going to spoon feed you.

"At what point have I said amplifiers don't sound different, despite their similar distortion measurements? I propose reasons for that all the time, and say that distortion figures are almost meaningless for how good something will be since it's subjective and shows pretty much no correlation."

What do you propose then other than an amps deviation from linearity for its sound character?

Yes, THD and IMD as single numbers are meaningless...Geddes demonstrates as much, showing no correlation between THD and IMD and listening tests. I am not talking about nor have I been talking about those metrics. The content behind those metrics matters though. The metric of Geddes or Cheever show much more promise...hell even the metric from the 1950s by BBC engineer D.E.L Shorter works better.

"I just said exactly that designers aim for 3rd harmonic or lower"
What does this mean? You are not writing clearly here. 3rd harmonic or lower what?? Go look at amp measurements, you will see many amps with harmonics out to at least 20th as common. These negatively impact sound quality. Antiquated?? I think not. BTW, Pass talks the talk, but measurements of his amps shows he is not walking the walk.

"It's not exactly hard, or new, to model the types of harmonic distortions topologies will produce. "

Apparently you are wrong. And it seems to be very hard to design amps to fit to psychoacoustic hearing models...only one mfg. even claims this.

"Atkins says despite the higher order harmonics than you'd expect, they don't appear to play any role"

He has not based his statement on anything. Studies show that they will matter and will influence the outcome of the sound. Look at the comparison MF did between the Lamm ML3 and the big Dart. You will see that the descriptions of the Dart have everything to do with "speed" "transparency" "slam" but not about correct tonality and image/soundstaging , for which he praises the ML3. Clearly those harmonics matter. High order harmonics are known to provide an "edge" to the sound that can be perceived as greater detail or "speed". They also have the effect of making things sound closer because our perception of loudness is tied to higher order harmonics. The perception of louder also makes things sound closer...this impacts image 3d and soundstaging.

I don't care so much about the topic per se, only about 10% of the posts in this thread are strictly on topic. It does tie in; however, because how things are presented affects the perception of realism (point 1) and ties in to enjoyment as well (point 3). Whether or not it meets (2) depends on if you define accuracy from a strictly mechanical/measurement POV or if you take matching output with a psychoacoustic model as being a definition of accuracy. I take this as a definition of accuracy rather than a strict measurements basis. Measurements matter but not in the way they are generally being used. If a poorer measuring amp does things more correctly psychoacoustically than a better measuring one then that psychoacoustically correct amp will likely deliver better upon point 1 even though it is worse on point 2 and will likely deliver better on point 3 as well.

 

[morricab]

Hi Folsom,

I think the wish of convergence is marred by the reality that A) many of us fundamentally disagree about the purpose of the mechanism; B) many of us fundamentally disagree about the nature of the art form; and C) we reach the limits of language when we attempt to describe another art form where those two methods of communication - one being language, the other being music - are neurobiologically distinct processes that do not share common overlap.

Given that music is only ever a perceptual phenomena, I think we need to move beyond the status quo this thread - and millions of others - risks returning to, in the manner the Bible would describe as a dog returning to its own vomit.

The problem is that currently we have this:

View attachment 30664


Personally, I think a way forward must involve this:

View attachment 30665


My personal belief is that until we have a greater understanding of how and why the brain processes music separate not only from language but also from sound, we will fall into a dialectic between subjective and objective observations in which the problem of language acts an impediment to understanding, as the endless debates this hobby has continually occupied itself with have clearly demonstrated.

Peace and love,

853guy

Nice post! I would agree with the triangular concept you have presented as a way forward. This is the psychoacoustic factor (you call neurobiological but I see that as the same). Some work has been done but a lot more would definitely be beneficial to bridge the gaps.