Do equipment stands have an impact on electronics?
Mechanical grounding or isolation from vibration has been a hot topic as of late. Many know from experience that footers, stands and other vibration technologies impact things that vibrate a lot like speakers, subs or even listening rooms (my recent experience with an "Energy room"). The question is does it have merit when it comes to electronics and if so why? Are there plausible explanations for their effect on electronics or suggested measurement paradigms to document such an effect?
BTW Ralph, you don’t have to keep saying stuff like "You don’t seem to
understand." I’m certain there’s much here that you don’t understand,
I don’t feel the need to insult you by using such language.
No, you use obscene, vulgar language here to insult - hence your multiple deleted posts. Ralph is doing fine, Whiner, and has contributed much here.
Hey wait, I have an idea! Tell me if you agree before I spend the hour
or so this will take: I'll prepare clips of the same two examples in my
Audibility article, but they'll be longer and I won't tell you there the
nasty noise starts and stops. I'll put them on my site and post the
links, then you'll play the clips and tell me where you think the noise
is present. Then I'll tell you if you're correct or not. If you fear I'd
lie about the locations, I'll be glad to email the answers in advance
to a disinterested third party.
Deal?
Here's the problem with that! First: That test is not testing for the problem. Its essentially demonstrating the ear's masking principle. All this time, I've been talking about something else.
Second: I've worked really hard to make sure my gear lacks the higher ordered artifacts that cause brightness. As a result, even at 100db my system has a relaxed presentation (it doesn't sound loud- you don't realize how loud its actually playing until you try to talk to someone right beside you).
Part of what makes that possible is to not give it a source that is inherently messed up! When you post a sound file, its **digital**. Once its in whatever codex, the associated artifacts that allowed it to get there are inherent in the file- no matter how good the intentions. Once there, they can't be removed. this makes it unsuitable for the caparisons I would want to demonstrate.
An alternative would be to encode the material on an analog format, so the artifacts in question aren't inherent and instead are added. I'm betting that's not going to happen.
An additional problem- the one with going to your house- is that in doing so, the test has to be heard through gear that is known to contribute similar artifacts. This makes it tricky to make any sense of the results and I'm pretty sure is part of why you've already seen null results.
BTW Ralph, you don’t have to keep saying stuff like "You don’t seem to
understand." I’m certain there’s much here that you don’t understand,
but I don’t feel the need to insult you by using such language.
I was attempting to pin you down on a point, which you've sidestepped pretty consistently. That suggests to me that its possible that you've not dealt with the topic before. "you don't seem to understand" is a shorthand way of conveying that; please note the word 'seems' that I was careful to include in that phrase and it was in no way intended to be insulting.
Put another way, you freely acknowledge that analog and tubes have artifacts that cause them to be 'warm' (while measuring perfectly flat on the bench) but so far you don't seem able to also acknowledge that transistors and digital also have artifacts but of a different nature that cause the aspect of 'brightness' and 'hardness' which are also colorations. This too suggests a lack of understanding, but it might simply be a reluctance to cede the point.
FWIW, the fact that trace amounts of the 7th order causes a metallic quality in the sound is something that has been known since the 1930s. So I don't see it as any stretch at all to simply acknowledge that such could be the case. I really don't want to devote more time going round and round on the topic than you do.
At any rate y'all, (including you, Ethan), Enjoy the holidays!
Atmasphere help me understand the artifacts you talk about. Is this related to the fact that human hearing is not flat but more sensitive at certain frequencies as shown here or something else?
I can understand that if music occurs at frequencies where the ear is most sensitive it would have more impact/effect. I understand the rules of human hearing as depicted here. Does this show what you are saying?
This says music noise or distortion, whatever occurs at 4 kHz Is of greatest consequence..
The chart also shows mostly harmonics of instruments at 4 kHz. Are these the harmonics you are talking about?
There is a select group of professional recording engineers now working who are considered the best in the business, responsible for some of the best sounding recordings ever made---lifelike instrumental timbre, high resolution and transparency, who can record on any equipment they choose. They have no allegiance to any system, just to getting the best sound possible. One such engineer is Kavi Alexander of Water Lily Records, located in Santa Barbara California.
Kavi not only continues to prefer analog tape to digital (though higher bit rates and sampling frequencies---24/192, are narrowing the gap), but he uses a very customized recorder that employs tubes! He does so NOT because of any "musical distortion" the recorder adds to the direct mic feed, but for the exact opposite reason---it is the most transparent, least distortion-adding method of recording he has found.
Kavi’s has produced some of the most astonishingly lifelike recordings ever made, including the Grammy Award-winning "A Meeting By The River", on which master slide guitarist Ry Cooder plays. Ry is VERY serious about the sound of his guitars (both live and recorded), which led him to make the first digitally recorded Pop (non-Classical) album, Bop Til You Drop. He HATED it! When he heard a Water Lily label recording he asked "Why don’t my records sound this good?". He sought out Mr. Alexander, and plans were undertaken to make the AMBTR album. It is World Music, and one of the handful of best recordings I’ve ever heard..
The Water Lily recorder’s tube circuits were designed by Tim Paravicini, who has also done work for the David Gilmore/Pink Floyd Studio in London, considered one of the best in the world. Tim also designs consumer Hi-Fi products for EAR-Yoshino, including tube pre-amps, power amps, and digital products. EAR-Yoshino has one phono pre-amp that is all solid state, which Tim preferred in that application. He, like Kavi, generally prefers tubes to solid state, not for their "musical distortion", but for their sonic superiority. One may disagree with that preference, but one can not truthfully claim that their preference is based on a desire for "musical distortion".
Thanks for that. I own Indian Architecture and agree his recordings are magnificent.....
FWIW, the fact that trace amounts of the 7th order causes a metallic quality in the sound is something that has been known since the 1930s. So I don't see it as any stretch at all to simply acknowledge that such could be the case. I really don't want to devote more time going round and round on the topic than you do.
Reference? How did they arrive at that conclusion?
Agear Atmasphere: FWIW, the fact that trace amounts of the 7th order causes a metallic quality in the sound is something that has been known since the 1930s. So I don’t see it as any stretch at all to simply acknowledge that such could be the case. I really don’t want to devote more time going round and round on the topic than you do.
Reference? How did they arrive at that conclusion?
Really. Besides, lots of things cause that metallic quality. E.g., RFI/EMI, vibration, background scattered light. As I’ve oft stated, in addition to that metallic quality there’s that thin quality, the rolled off quality, the bass shy quality, the congealed pablum quality, the screechy irritating quality, the electronic quality, the boring empty quality, the recorded-in-a-barrel quality, the uninterleaved quality. I trust I’m not the only one who hears it, am I?
Really. Besides, lots of things cause that metallic quality. E.g., RFI/EMI, vibration, background scattered light. As I’ve oft stated, in addition to that metallic quality there’s that thin quality, the rolled off quality, the bass shy quality, the congealed pablum quality, the screechy irritating quality, the electronic quality, the boring empty quality, the recorded-in-a-barrel quality, the uninterleaved quality. I trust I’m not the only one who hears it, am I?
Agreed 100%. RFI/EMI is a biggie although a lot of people think that's hogwash as well (along with the subject of this thread).
Yes, thanks Ralph, Merry X’s and Happy Holidays to all of you. Even the haters. I never get angry about this stuff. Really. I mostly just enjoy the challenge of explaining things to those who are clearly reluctant to learn. So this is my last comment for now:
As always, a believer (you) when challenged to describe a test he’s willing to take, finds a reason to avoid being tested at all. Ralph, the only analog source I have is a cassette deck, and I have an acoustic guitar. So you tell me exactly how to add gated hash noise while I capture my playing to tape in a way that challenges you to identify the noise, and I’ll send it to you. Or any other very specific and practical scenario you can describe. If you’re unable to describe any practical test I can give you (or others here) that lets you prove you can hear what you claim, I’ll be very disappointed in you (though not surprised).
But really, your claim is disingenuous on its face. All my Artifact Audibility test attempts to show is at what level below music a nasty sounding artifact can be heard. It has nothing to do with digital always adding disturbing artifacts, or whatever it is you believe. If that were even true, those artifacts would show up when recording and playing back a pure sine wave, or some other known source. So already your claim is easily proven false using basic audio test equipment. I should have posted this link earlier:
Therefore, your criticism of my test is not based on logic, but rather on a denial of basic audio principles. You can’t hear stuff when it’s 80 dB down! And in most cases you can’t even hear it when it’s 40 dB down. If you can’t hear that nasty noise when it’s 40-60 dB below the music, then you can’t hear any of the other stuff you claim people hear that makes digital sound unappealing. I’m sure you realize this. Either that, or you’re engaging in magical thinking. So please let’s resolve this so you can prove your point. If I’m wrong I’ll gladly admit it. Heck, I need to know if I’m wrong! I doubt I am, but I’d like to know for sure.
Geoffkait: Really. Besides, lots of things cause that metallic quality. E.g., RFI/EMI, vibration, background scattered light. As I’ve oft stated, in addition to that metallic quality there’s that thin quality, the rolled off quality, the bass shy quality, the congealed pablum quality, the screechy irritating quality, the electronic quality, the boring empty quality, the recorded-in-a-barrel quality, the uninterleaved quality. I trust I’m not the only one who hears it, am I?
agear Agreed 100%. RFI/EMI is a biggie although a lot of people think that’s hogwash as well (along with the subject of this thread).
Things that are more noticed when they are removed than they were by virtue of their presence. It wasn't until I heard the transparency provided by an electrostatic loudspeaker that I realized just how colored, veiled, and opaque cone speakers were.
One of the intrinsic benefits of the long term listening audition of any given component is that the character of that component is often more readily apparent when the component is removed from the system than when it was inserted.
bdp24 Things that are more noticed when they are removed than they were by virtue of their presence. It wasn't until I heard the transparency provided by an electrostatic loudspeaker that I realized just how colored, veiled, and opaque cone speakers were.
That's so true! There is also the Last Tweak Syndrome at work here. For any red blooded audiophile who has integrated some tweaks into his system over the years there comes a point when he says to himself, gee whiz, it can't get any better than this, can it? Then the next tweak comes along and he says, Gosh, now it really can't get any better, can it? So the skepticism of many folks is not completely without merit. It's the Last Tweak Syndrome in action.
But really, your claim is disingenuous on its face. All my Artifact
Audibility test attempts to show is at what level below music a nasty
sounding artifact can be heard. It has nothing to do with digital always
adding disturbing artifacts, or whatever it is you believe. If that
were even true, those artifacts would show up when recording and playing
back a pure sine wave, or some other known source. So already your
claim is easily proven false using basic audio test equipment. I should
have posted this link earlier:
What your Artifact test does is demonstrate the masking principle. It does not get at the issue of how artifacts introduce coloration by adding brightness. It does very effectively show how a sound that's 40 db down (or even less) might not be audible when louder sounds are present.
I think I have a Nakamichi machine still laying around somewhere. I would need refurbishing though. Most of the rubber bits have perished.
Here is the problem: When you are demonstrating an artifact like the effect of aliasing (which should be inherent in your digital gear) you can't use the same gear to show 'with' and 'without'; that won't work since it would always be 'with'.
Distortion (including aliasing or inharmonic distortion) is a bit insidious as there is this assumption that the distortion artifacts are masked or buried in the noise. Sometimes this is true (certain harmonics can mask the presence of other harmonics) but the ear has a way of allowing us to pick out very low distortion artifacts not by detecting them as themselves, but by converting them to tonality. In a way they ride on top of the signal rather than at the bottom (metaphorically speaking). So what we would be looking for in a test is to see which is brighter (without actual FR errors being introduced).
This, Ethan, is why I've been wondering if you don't 'get it'; your responses to me have all been about masking, which is something other, and something I don't contest (masking being an important rule of human hearing). Perhaps it might help to know that in the last ten years, Dr. Herbert Melcher has shown that the human ear/brain system has tipping points. An example of that is if the playback has insufficient speed (risetime) the brain has a tipping point where the music processing is transferred from the limbic centers to the cerebral cortex.
Another example of a tipping point is where the brain will favor distortion as tonality over actual FR errors! Now both of these things were not known back in the 1970s and are examples of 'now that we know that, we can do proper engineering to take them into account.'
So in a case where we want to demonstrate aliasing, or how the presence of trace amounts of higher ordered harmonic distortion can be detected without hearing the actual tones, its likely that the test would be constructed on a platform that first is immune to the problem itself, so that the problem can be demonstrated. Then once that is done what we are looking for is tonal differences between the two examples 'with' and 'without'.
You can see right away the difficulty! To demonstrate aliasing, it can't be done on a digital system since aliasing is inherent; to demonstrate higher ordered harmonics you can't have them inherent in the system which probably means no transistors in the signal path.
Atmasphere help me understand the artifacts you talk about. Is this
related to the fact that human hearing is not flat but more sensitive at
certain frequencies as shown here or something else?
It does matter that our ears are tuned to bird song frequencies (IOW Fletcher-Munson); this is the result of evolution as birds are the early warning system of the presence of a predator in the environment. You can regard this extra sensitivity as a complication!
But its more than that- the ear/brain system converts distortion to tonality. This is why one amp can sound bright while another does not, even though while on the bench both amps measure flat. The difference is that the former has more higher-ordered harmonic distortion and so sounds bright despite being perfectly flat in bandwidth.
Seventh harmonic causing a metallic quality: I've heard that several places, but in this case the easiest to remember is John Curl (one of the top solid state designers alive today). https://www.youtube.com/watch?v=fZwS-oyqc3w
We can hear it, we can measure it, there have been thousands of experiments over the years, some written up in peer reviewed audio engineering journals. Vibration effects in equipment are orders of magnistude more significant than the tiny differences cables make (unless they're just clumsy cheap tone controls due to their reactance) BUT unless you intend tapping your cabinet along with the music, just put another tune on, pour a drink & enjoy
do you have citations to any of the there have been thousands of experiments over the years, some written up in peer reviewed audio engineering journals??
I have access to most engineering journals and would like to look at the articles.
Ralph, this is very simple, and you have danced around it repeatedly:
If the "digital" artifacts you refer to are loud enough to be audible, then how come they don't show up in a standard FFT measurement? Or in a standard THD test that nulls the test frequency and leaves everything else. You already agreed that stuff 40-80 dB down is too soft to hear when it starts and stops in my Artifact Audibility test, so by extension it's too soft to influence "tonality" either. Aliasing, and all the other bugaboos you talk about, are 100+ dB down. And so they are inaudible. This is very simple audio basics, and clearly the burden of proof is on you to prove otherwise. Since you still haven't described a test you're willing to take that will let you prove your beliefs, it's clear that you're unable to do so.
Here's direct question I hope you'll answer: Since you are unable to prove your beliefs, I can only assume you haven't proven them to yourself either. So doesn't it make sense for you to do some experiments, so you will know that your beliefs are valid? I'll be glad to hear how you would test yourself!
Perhaps it might help to know that in the last ten years, Dr. Herbert Melcher has shown that the human ear/brain system has tipping points. An example of that is if the playback has insufficient speed (risetime) the brain has a tipping point where the music processing is transferred from the limbic centers to the cerebral cortex.
Reference, and how did he discern such a transference? PET scan? I am in medicine, and no Neurologist (or neuroscientist) has such specificity at their fingertips. They are only making assumptions based on observed brain activity.
Another example of a tipping point is where the brain will favor distortion as tonality over actual FR errors! Now both of these things were not known back in the 1970s and are examples of ’now that we know that, we can do proper engineering to take them into account.’
Again, we need a reference. Makes for good audio prose and ideology but there is no data.
It does matter that our ears are tuned to bird song frequencies (IOW Fletcher-Munson); this is the result of evolution as birds are the early warning system of the presence of a predator in the environment. You can regard this extra sensitivity as a complication!
purely speculative.
seventh harmonic causing a metallic quality: I’ve heard that several places, but in this case the easiest to remember is John Curl (one of the top solid state designers alive today). https://www.youtube.com/watch?v=fZwS-oyqc3w
Again, no data. I guess we need to find that "big red book."
"Perhaps it might help to know that in the last ten years, Dr. Herbert Melcher has shown that the human ear/brain system has tipping points. An example of that is if the playback has insufficient speed (risetime) the brain has a tipping point where the music processing is transferred from the limbic centers to the cerebral cortex."
That wouldn’t be THE Dr. Hebert Melcher, would it? 😬
When he he says the human ear/brain has tipping points is that anything like tipping over a cow? No one seems to understand how hearing works, and I’m not talking about the inner ear, the neurons or the transmitters or the cerebral cortex. Give me a break! It’s that way of thinking that’s SO wrong-headed and just plain dumb. I’m quite sure if there is someone out there who does understand how we hear it most likely ain’t Dr. Herbert Besides just to clarify my position if you can't hear or aren't sure what you're even listing to all the measurements and high faluting "scientific" explanations won't help. You're up the creek without a paddle.
@agear regarding the 7th harmonic. Two minutes on google will turn up ample references from piano tuning, design of wind instruments and so on. Here’s a basic one to get you started
Ralph, this is very simple, and you have danced around it repeatedly:
If
the "digital" artifacts you refer to are loud enough to be audible,
then how come they don't show up in a standard FFT measurement? Or in a
standard THD test that nulls the test frequency and leaves everything
else. You already agreed that stuff 40-80 dB down is too soft to hear
when it starts and stops in my Artifact Audibility test, so by extension
it's too soft to influence "tonality" either. Aliasing, and all the
other bugaboos you talk about, are 100+ dB down. And so they are
inaudible. This is very simple audio basics, and clearly the burden of
proof is on you to prove otherwise. Since you still haven't described a
test you're willing to take that will let you prove your beliefs, it's
clear that you're unable to do so.
Here's direct question I hope
you'll answer: Since you are unable to prove your beliefs, I can only
assume you haven't proven them to yourself either. So doesn't it make
sense for you to do some experiments, so you will know that your beliefs are valid? I'll be glad to hear how you would test yourself!
Actuallly Ethan we must be talking past each other. I feel also that you've not been addressing my points, and when I stated that you didn't seem to understand, you objected but nothing happened. I've answered your question in the second paragraph about 5 times now! So I have to assume that my assertion was correct- you really don't get it! Let's start with this one:
you already agreed that stuff 40-80 dB down is too soft to hear
when it starts and stops in my Artifact Audibility test, so by extension
it's too soft to influence "tonality" either.
This statement is false and describes a basic misunderstanding of how distortion interacts with the ear (much of which has been known since the 1930s). Because of the masking principle, louder sounds make it difficult or impossible to hear quieter sounds. But distortion is different from sounds buried in the mix. In a way it rides on top of everything else and so is **always** audible. Again, this understanding has been with us since the 1930s. The way you seem to be looking at it is that somehow distortion gets buried under that rest of the signal, especially if its a loud one. If that were true we would not need to bother with the distortion spec of an amplifier at full power as it would be irrelevant! Clearly it is not.
Since you still haven't described a
test you're willing to take that will let you prove your beliefs, it's
clear that you're unable to do so.
I've described a test at least three times now. Please go back and reread my comments.
Here's direct question I hope
you'll answer: Since you are unable to prove your beliefs, I can only
assume you haven't proven them to yourself either. So doesn't it make
sense for you to do some experiments, so you will know that your beliefs are valid? I'll be glad to hear how you would test yourself!
This paragraph opens with a false assumption. When I first read the results of the GE study (mid 1960s) I set up some simple test equipment and was able to show easily that the ear is indeed far more sensitive to higher ordered harmonics. That and that they are unpleasant to the ear is no surprise- just listen to a square wave sometime. Actually Ethan when it comes to challenging each other like this, I've seen occasions where you did not have measurements at your disposal (ex.: power cords) so I think its a little odd that you think I might not have sorted this stuff out for myself. I suggest that you start by obtaining some documents and read them- the writings of Norman Crowhurst are immensely beneficial; if you're serious many of them can be downloaded from Pete Millet's website. Another nice tome to have on hand is the Radiotron Designer's Handbook (John Curl refers to it in the YT link I dropped earlier).
Its not peculiar that I think that the ear converts distortion into tonality **as you are suggesting** with the use of the word 'beliefs'. I've seen this before in skoftics (a term describing a person that seems skeptical, but when confronted will not examine the evidence as their position is based on belief and changing that belief is anathema to them), where they go so far as to contradict themselves as you are here in an attempt to make the other person in the conversation wrong.
By that I am pointing out that you admitted easily that a 2nd harmonic is easily audible as 'warmth'. So you allow for that, but you don't allow that other harmonics to which the ear is **far** more sensitive, can't be heard because they are at a lower level?
I have maintained that understanding of the physiology of how we perceive sound (in a nutshell, the rules of human hearing) is essential to progress in audio and is the arena of continuing advance in our field. From my perspective, your understanding of those rules seems stuck about the 1970s or so. A lot's gone down in the research of human physiology since then; if you were up on it we would not be having this conversation!
FWIW, two of the greatest solid state designers of our time are- John Curl and Nelson Pass. It should come as no surprise that they are responsible for some of the best-sounding solid state amps made.
Ralph, I read your posts several times. You didn't describe a test you're willing to take. Rather, you wasted several paragraph explaining why it's impossible to devise such a test: Your cassette deck needs new rollers, a special platform must be constructed, and - most incredible of all - you can't demonstrate digital aliasing on a digital system. :->) What a waste of both your time and mine this has been.
Your belief that distortion is different from "artifacts" and so can be heard at infinitesimally small levels is preposterous. I challenge you to prove it. Hint: you can't because it's not true. And your other belief, that distortion "brightness" is different from frequency response brightness, is equally preposterous. If you change the spectrum, how and why it changed is irrelevant. If you add 10 percent 3rd harmonic distortion to a 1 KHz triangle wave, that's exactly the same as boosting an EQ by about 1 dB at 3 KHz.
Again this is such basic stuff that I now have my answer: You do know that what you're claiming is nonsense, but you do it anyway to sell stuff. So I'm pretty well done here, though I still look forward to your proof that
distortion is always audible even when it's 80+ dB below the music.
@agear regarding the 7th harmonic. Two minutes on google will turn up ample references from piano tuning, design of wind instruments and so on. Here’s a basic one to get you started
Anything pertaining to the design of amplifiers or better yet the effects of isolation on said harmonics? Again, two minutes on Google provided about as much intel as the youtube video from Townsend.
Ethan, since you are an actual musician as well, please educate us on the potential evils of 7th order harmonics and how they might manifest in a system and/or room....
Ralph, I read your posts several times. You didn’t describe a test you’re willing to take. Rather, you wasted several paragraph explaining why it’s impossible to devise such a test: Your cassette deck needs new rollers, a special platform must be constructed, and - most incredible of all - you can’t demonstrate digital aliasing on a digital system. :->) What a waste of both your time and mine this has been.
Actually I did. I said (again) that it would have to be on a system that lacked the artifacts under test. So to test aliasing, it would be on a system that is immune to such (an analog system). To test for higher ordered harmonics, on a system that lacks said (likely tubes). The test would be the same track, one ’with’ then the same ’without’.
I can easily make a recording of the 'with' and 'without problem of aliasing.
Your belief that distortion is different from "artifacts" and so can be heard at infinitesimally small levels is preposterous. I challenge you to prove it. Hint: you can’t because it’s not true. And your other belief, that distortion "brightness" is different from frequency response brightness, is equally preposterous. If you change the spectrum, how and why it changed is irrelevant. If you add 10 percent 3rd harmonic distortion to a 1 KHz triangle wave, that’s exactly the same as boosting an EQ by about 1 dB at 3 KHz.
Proof: analog and tubes are still very much alive, decades on after being declared ’obsolete’ (the market knows what’s up even if you don’t). But that’s not all: tubes/transistors debate (and the complaint against transistors is ***brightness***, when clearly there is no FR error, as I have explained....); the analog digital debate (again: brightness is the coloration...). Both of these debates are older than the web. And distortion is at the root of both of them. You **know** this!
In case its not clear, all audio products make distortion and all audio products have a coloration as a result. So even in this day and age its still all about the distortion.
The 3rd harmonic is not an example as I’m sure you knew when you wrote that. I’ve been careful to say ’higher ordered harmonics’, which are the 5th and above (the ear being relatively insensitive to the lower orders, the 2nd, 3rd and 4th). Your comment fits the definition of a Strawman to a ’T’.
Adding 0.05% of the 7th wouldn’t even show up in a FR analysis- but its easily heard. Go back to that link of John Curl:
The book he refers to is the RadioTron Designer’s Handbook, a reference tome known to many. I have both the 1941 and 1953 editions (the latter is the red one). If you think you can make a better amp than he or Nelson Pass (or Charlie Hanson, IMO responsible for one of the other great solid state designs), let’s see you get out there and do it.
Again this is such basic stuff that I now have my answer: You do know that what you’re claiming is nonsense, but you do it anyway to sell stuff. So I’m pretty well done here, though I still look forward to your proof that distortion is always audible even when it’s 80+ dB below the music.
Apparently I was right that you don’t seem to understand why its important to get rid of distortion. If what you say were true, 10% would be unimportant as you would never hear it (by your way of thinking, your masking demo shows that in spades)! But its obvious that isn’t the case and you confirm that by insisting as I do that distortion should be low. The contradiction is obvious. I am currently of the impression that you are so intent on making me wrong that you don’t care if you contradict yourself.
I suggest once again that you read Norman Crowhurst.
Remember what I said about blind spots? This is an example of something where you act like you don’t seem to know, and you act like you don’t seem to know that you don’t know it. That was why I brought it up the first time and your posts have very consistently proven me correct.
agear, I’m glad you asked about harmonics in the context of music. Before I made my last post above I checked my Musical Notes chart to see how out of tune various harmonics are. Here’s the chart which shows a tempered scale, though that’s what everyone plays so those are the appropriate frequencies to consider:
So looking at my chart it’s clear that the 2nd, 4th, and 8th harmonics are all perfectly in tune, and thus "consonant" (versus dissonant) with an A note because they’re perfect octaves. The 3rd harmonic at 330 Hz is very close to an E, which is in the key of A major and A minor, so we’re good there too!
Next is the 5th harmonic at 550 Hz. That’s a few Hz flat of a C# which is the major note in an A major scale. So that will sound a little off if it’s loud enough to hear. But what if the music is in the key of A minor? Now that 550 Hz is way out of tune because the deciding note for minor is the C natural at 523 Hz. Fortunately, harmonics usually (though not always) decline in level as you go higher, so with normal causes of distortion the 5th harmonic is pretty soft in any competent audio gear.
And now we get to the famous 7th harmonic, or is that infamous? LOL. Here 770 Hz falls between an F# and a G, being out of tune with both. So yeah, it would be a problem if it were loud enough to hear. But again, with competent gear it will be way down by the noise floor and thus inaudible due to both its low level and masking by the rest of the music. The claim that high-order distortion components are somehow magically audible even when they’re incredibly soft is itself incredible. And as we all know, the more outrageous the claim, the more compelling must be the proof. Though at this point I’d settle for even minimal proof, as opposed to "because John Curl said so." :->)
Of course, as I have pointed out literally dozens of times in my various articles and videos, whenever you have harmonic distortion (THD) you also have similar amounts of IM distortion (IMD). And IM distortion is usually out of tune with the music, and so is much more audible and damaging than most forms of THD including the 7th harmonic. Chasing increasing small amounts of high-order THD in the presence of large quantities of IMD is like chasing unicorns.
whenever you have harmonic distortion (THD) you also have similar
amounts of IM distortion (IMD).
This statement is misleading. You can have a fair amount of THD and still have relatively low IMD figures. This is however a very common saw and often it **happens** to be true; its just not true 100% of the time.
And IM distortion is usually out of tune
with the music, and so is much more audible and damaging than most
forms of THD including the 7th harmonic.
This statement is true.
Chasing increasing small
amounts of high-order THD in the presence of large quantities of IMD is
like chasing unicorns.
This whole thread has taken a nasty and totally unnecessary turn. In the first place ever since the bullet headed amplifier reviewer from Audio Review opined that all amplifiers that measure about the same sound the same, audiophiles who actually can hear have laughed at anyone who demands proof or measurements. A lot of you young whipper snappers are too young to remember the big solid state amp vs tube amp debate from the 80s. But noone could explain completely why a solid state amp with vanishingly low 0.0005% THD could sound SO %€$@! BAD relative to a reasonably good tube amp with 0.05% THD, which according my calculations is TWO ORDERS of magnitude - or for those technically challenged - 100 TIMES HIGHER than the solid state amp’s THD. Hel-loo!
Crown amps of the early 70s had 60db of negative feedback and no distortion.??vs a Marantz 8b that had over 1 % thd..but you could listen into it all nite long. Tom
Heck, I'll quote it: (from Stereophile, measurements by John Aitkinson):
Whenever I measure one of Vladimir Lamm's amplifiers, I am always
impressed by the quality of the engineering. Yes, the ML2.2 has a bent
transfer function, which means that it produces higher-than-usual levels
of second-harmonic distortion—but this is not accompanied by high levels of high-order intermodulation. And you have that low output impedance and very wide bandwidth!—John Atkinson
I don't know what a "bent" transfer function is, but I'd need to know the specifics of the test. What frequencies, what levels, what amounts of each distortion type, and so forth. I know you can do the opposite: create more IMD than THD using a "full wave" multiplier. But anything that changes the waveform enough to add THD will add similar amounts of IMD. Not that John Atkinson is what I'd call a reliable audio reporter anyway.
I notice that you quote people like JA and John Curl in lieu of
providing evidence. If you read my many articles and watch my many videos, you'll see they all include lots of evidence. Microphones capturing the sound of different diffuser types, audio examples of both static and changing phase shift, measurements and audio recordings that let people hear exactly what to expect from acoustic treatment, and so much more. Versus literally zilch from your side of the aisle. :->)
I'm still hoping you'll tell me all about the tests you've done yourself that led you to your beliefs. Actually, I'm still hoping for a lot of things from this thread, such as what Tom's patents are for, and half a dozen things I've asked of you that you never answered.
"I noticed that you quote people like JA and John Curl in lieu of providing evidence. If you read my many articles and watch my many videos, you’ll see they all include lots of evidence. Microphones capturing the sound of different diffuser types, audio examples of both static and changing phase shift, measurements and audio recordings that let people hear exactly what to expect from acoustic treatment, and so much more. Versus literally zilch from your side of the aisle. :->)"
Pretty clever! You’ve changed your tune from demanding proof to demanding evidence. That’s a new wrinkle in an otherwise tepid and snooze-worthy exchange. Could Nathan be softening? Could Nathan be rethinking his position? Are we about to witness an epiphany? Don’t touch that dial! Talk among yourselves. Smoke if ya got em.
I don't know what a "bent" transfer function is, but I'd need to know
the specifics of the test. What frequencies, what levels, what amounts
of each distortion type, and so forth. I know you can do the opposite:
create more IMD than THD using a "full wave" multiplier. But anything
that changes the waveform enough to add THD will add similar amounts of
IMD. Not that John Atkinson is what I'd call a reliable audio reporter
anyway.
Again your statement is false. You can have rather low IMD while THD might be ten times higher or more. Digital audio is a good example, as aliasing is a form of IMD, while THD is almost non-existent. You can't have it both ways!!
Instead of trying to make the world wrong why don't you read the article at the link instead of the innuendo? (BTW a bent transfer function is one that has a bend in the linearity curve) Its all there. I'm not a fan of John either (having nothing to do with his testing); if he makes a report on a test, then the test is pretty reliable (I caught him once on a bug in one of his tests, but the bug related to a design flaw in his test gear at the time, so that was understandable).
Again: Read Norman Crowhurst. This will give you a good grounding.
If you want to know how to build an amplifier (not that you do, this is academic) that can have low IMD while THD might be much higher, you have to start with zero feedback, and then sort out where the distortion sources are and reduce or eliminate them. Victor Lamm knows his stuff- very impressive specs for an SET.
So I just provided evidence, but you aren't interested. That is the definition of a skoftic which is very different from a skeptic.
JA and John Curl **are** evidence. Apparently you don't know the difference between evidence and proof. I think you are asking for proof but at the same time your website isn't that either. Any of your sound files can be doctored and there is no way a person going to your site has any way of knowing if they are the real thing or not. IOW, your site is 'evidence' as well, not proof. I also detect a bit of hubris- that somehow you place yourself above accepted masters in the field.
John Curl is not just evidence but proof in that his designs are well-recognized decades on. Clearly he knows his stuff and he's been at if for decades. You're really going out on a limb trying to make me wrong by attempting to impugn John Curl!!
I recommend you get an oscilloscope and look at what waveforms look like. A 'scope allows you to do that- to view the same signals that might be driving an amplifier or loudspeaker. You can also view distorted waveforms on a scope and compare them to undistorted waveforms. I think you might already know this although your posts seem to belie it; so if you are looking at a distorted waveform, how can you tell? If you are able to answer that it might give you a clue as to why distortion is much more audible than you think.
One other thing: you are ignoring is how the ear works. It is far more sensitive than test equipment to higher ordered harmonics and there is a reason for that. Again, an example of not knowing what you don't know. Without that understanding, I can see it would make it hard to see how the ear could detect distortion of only 0.005% or the like. I suggest you read up (perhaps set up that demo I posted earlier) and see for yourself.
Some people's ego doesn't allow them to contemplate how little of our brains do we use, how little we know. A healthy dose of a psychedelic can help with that.
"The writer William S. Burroughs once wrote a response to his good friend, poet Alan Ginsberg, who had asked Burroughs why he hadn't dissuaded him beforehand against doing something that resulted in an unpleasant experience for Ginsberg. Burroughs, older and wiser, simply replied that he didn't say anything because "you can't tell anybody anything they don't already know." That's putting it rather in the extreme, but it's another way of saying that some people just don't get it and never will."
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