😉
@hbtaudio : "... ignore list"
Defiant phase over;-? Ready to face challenges and tasks? And to follow some advice of others;-?
I have the impression that you, unlike the majority here, want to be able to distinguish between glossy labels and content. Where it says audio on it, it doesn't always have to be audio in it;-) And the more praise is given to high-end and the best measured values and the more elaborate it gets, the more...
But you want to be an Audio engineer;-) (I don't think I'm capable of developing airplanes either, I don't even know the basic requirements for an airplane, or cars, or mowers, or lifts, or computers, or radio, or...-)
Prerequisite for being an Audio engineer is to do AUDIO homework(-:
But since the sound is not only determined by the circuitry but also by the realization and components... later;-)
@hbtaudio : "... ignore list"
Defiant phase over;-? Ready to face challenges and tasks? And to follow some advice of others;-?
I have the impression that you, unlike the majority here, want to be able to distinguish between glossy labels and content. Where it says audio on it, it doesn't always have to be audio in it;-) And the more praise is given to high-end and the best measured values and the more elaborate it gets, the more...
Engineer, okay. Others as well;-)
But you want to be an Audio engineer;-) (I don't think I'm capable of developing airplanes either, I don't even know the basic requirements for an airplane, or cars, or mowers, or lifts, or computers, or radio, or...-)
Prerequisite for being an Audio engineer is to do AUDIO homework(-:
Then we will be able to assess "Tim" in terms of AUDIO suitability;-)
But since the sound is not only determined by the circuitry but also by the realization and components... later;-)
Correlation is one of the best tools of all.
So "no", what do you want me to confirm? As a human being, I don't care who prefers what kind of listening pleasure, whether distorted, noisy, hummed ...
What our comrade-in-arms Cummb is probably perpetuating is the fact that you can simply listen without any knowledge of the objectively available measurements, data and specifications or a minimum standard.
Without knowledge (or belief) I am not biased either - simply a BlackBox.
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Now I would like to stay on the physical-technical side of the “Tim” project alone and not have to answer questions that delve into other areas.
Nor do I have to answer questions about raising children (in their defiant phases) 😉.
HBt.
In my 50 yrs of audio engineering, not really, unless the designers are drastically incompetent. For instance very few people can hear 1% THD since it is harmonically related it could well be the instrument that sounds like it. For the same reason, you do not have a voice print in your brain of the singer (i.e. your mothers voice) else forget it with all the autotuning going on you would not even know. In my opinion, there is few things audio that is really right or wrong, if you enjoy it it is right. If you do not it is wrong. All we really want from a design is non self destructive properties and nothing that will destroy anything else following it. For the DIYers, there is nothing more important than to design something that sort of works and then tweaking it to your personal satisfaction and secondly there is nothing more satisfying that someone agreeing with some of the things you did. There is nothing so demeaning than someone putting you down and telling you that after your hard work that it is crap. Like someone telling Picasso that he messed up the last canvas only to reveal that it is worth millions.
Will do once i complete some sims to recheck those numbers as well as things like IMD, PSRR, slew rate and so on,
one is never cautious enough in our technical matters.
And you re right, i discarded the diamond buffer and used a triple EF with a dirt cheap BDV64C/65C pair of darlingtons,
by far not as good as the ones from Sanken when driven directly by the VAS, but way enough when buffered.
Actually everething has to be re evaluated, IPS, VAS and OS, that s why i didnt post anything as it would have been
half baked on all fronts if only one or two of those three stages were modded.
Also i abandonned the phase inverting scheme, because human ears will detect a large difference once an original
musical signal phase is inverted the original phase of the source should be absolutely preserved, otherwise that s no
more Hifi but just experimentation.
Greetings as well.
There have been rumors about audibility of absolute phase that I personally doubt.
Some googling produces links to AES papers, all behind a paywall.
Could you please give some link to substantiate this claim?
Some googling produces links to AES papers, all behind a paywall.
Could you please give some link to substantiate this claim?
I ll give you a short explanation and i ll post an article if i can find it somwhere in my old drives.
Say there s tight kick drum that is played, the microphone will be excited by a positive pressure at the start
of the signal, and this will be recorded as such by the recording apparatus.
When it will be reproduced by the player apparatus and amplified by a non inverting amplification it will be reproduced
by the speakers exactly as when you heard it in live, that is with an initial positive pressure applied to your tympanis.
If the reproducing apparatus invert the phase then the initial rising hedge will be actually a negative pressure applied
on your timpanis, and it s proved that an initial positive pressure produce the impression of a tight sound kicking hard,
while inverting the phase and hence applying an initial negative pressure will remove the tightness and hardness of the
sound even if it s exactly the same.
That s why it is important to respect the absolute phase of the signal, because in principle the recording sessions are
performed such that the signal phase is the same on the record than initialy captured, if you invert the phase of such
a musical signal you ll remove a main part of the information and your hifi system will have low definition even if it measure
extremely well electricaly speaking.
Say there s tight kick drum that is played, the microphone will be excited by a positive pressure at the start
of the signal, and this will be recorded as such by the recording apparatus.
When it will be reproduced by the player apparatus and amplified by a non inverting amplification it will be reproduced
by the speakers exactly as when you heard it in live, that is with an initial positive pressure applied to your tympanis.
If the reproducing apparatus invert the phase then the initial rising hedge will be actually a negative pressure applied
on your timpanis, and it s proved that an initial positive pressure produce the impression of a tight sound kicking hard,
while inverting the phase and hence applying an initial negative pressure will remove the tightness and hardness of the
sound even if it s exactly the same.
That s why it is important to respect the absolute phase of the signal, because in principle the recording sessions are
performed such that the signal phase is the same on the record than initialy captured, if you invert the phase of such
a musical signal you ll remove a main part of the information and your hifi system will have low definition even if it measure
extremely well electricaly speaking.
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Thank you, I am fine with your explanation concerning the signal path.
But this does not answer my question: " Is there a link to a substantial confirmation that absolute phase is audible"
Otherwise it is your personal assumption.
But this does not answer my question: " Is there a link to a substantial confirmation that absolute phase is audible"
Otherwise it is your personal assumption.
That s not a matter of signal path but of physical pression on the ears, an initial pression of the air on yours ears,
wich is a positive pressure, is different than a depression, that is, a negative pression.
When you hear a kick drum it s because a fast pressure/depressure is applied on your earing organ by compressed/decompressed air, the perception is not the same if the accoustic wave produce an initial positive pression or an initial negative pression, the sound will be perceived as tighter and harder if the accoustic wave produce a positive pression initialy.
To say it otherwise inverting the speakers cables will result in a different perception of the sound when listening to the
same piece of music, moreover if that s music with kick drums or a bass with the E string being thumped energically.
This difference of perception is not an opinion, it has been scientifically proved, and it s logical when you think of the ears
as being an organ thats is excited mechanically by an accoustic wave wich itself is nothing else than a succession of
pression/depression of the air, the frequency being the speed at wich a positive pression is followed by a negative pression.
wich is a positive pressure, is different than a depression, that is, a negative pression.
When you hear a kick drum it s because a fast pressure/depressure is applied on your earing organ by compressed/decompressed air, the perception is not the same if the accoustic wave produce an initial positive pression or an initial negative pression, the sound will be perceived as tighter and harder if the accoustic wave produce a positive pression initialy.
To say it otherwise inverting the speakers cables will result in a different perception of the sound when listening to the
same piece of music, moreover if that s music with kick drums or a bass with the E string being thumped energically.
This difference of perception is not an opinion, it has been scientifically proved, and it s logical when you think of the ears
as being an organ thats is excited mechanically by an accoustic wave wich itself is nothing else than a succession of
pression/depression of the air, the frequency being the speed at wich a positive pression is followed by a negative pression.
not sure whether the location of the listener (or drummer) in regard to the kick drum diaphragm might change the phase of the kick?
The listener is in front of the instruments, so when the kick drum membrane is kicked the air will be displaced in your direction
creating an initial positive pressure , if your position is behind then the initial pulse will start with a negative pressure.
Say you excite a speaker with a square wave that has 50Hz fundamental frequency, if the square wave start with a rising hedge
then the initial speaker motion will be in your direction and this start with an initial positive pression being applied on your ears.
Now let s invert the phase by 180 degrees, the initial hedge will be a falling one, the speaker will start its motion by moving
backward before moving forward after 10ms since the signal period is 20ms.
Bucks bunny, hope that the square wave exemple helped you understanding what i m talking about.
As i said scientific studies proved that the ear will not hear the same thing when the pulse start with a positive pressure
and when the phase is inverted by 180 degrees, wich in case of musical signals will result in a negative pressure being
applied on your ears by the air when a bass sound hit hard.
Positive pression mean that air is pushed inside your hearing organs pipe, while negative pression mean that air
is pulled out of your hearing organ pipe, that s just classic mechanics applied to air motion.
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Sound is much less determined by the electronics than by yourself, what sounded good 10 years ago could sound awfull
these days, actually it s sure 100% that it doesnt sound as well as it used to be.
Just look at page 29, you can ignore the rest.
https://courses.physics.illinois.ed...Notes/P406POM_Lecture_Notes/P406POM_Lect5.pdf
My last attempt to get an answer from you: Which "scientific studies" do you talk of? link?
That was a thorough scientifical study that i did read circa 2010, with curves showing the differences in human perception
of a same sound with the initial air motion either starting by pushing air or pulling air in the ears pipes, that is, a comparison between an initial pulse and the same one with 180 degrees inverted phase.
After 14 years or so you could imagine that i ve no more the link, i m not even using the same PC, if i have some time
i ll check in my collection of old HDDs if i downloaded the article, otherwise with some google searches you can find
some nearby articles in the waiting.
of a same sound with the initial air motion either starting by pushing air or pulling air in the ears pipes, that is, a comparison between an initial pulse and the same one with 180 degrees inverted phase.
After 14 years or so you could imagine that i ve no more the link, i m not even using the same PC, if i have some time
i ll check in my collection of old HDDs if i downloaded the article, otherwise with some google searches you can find
some nearby articles in the waiting.
To test this my advice is to use a loudspeaker without a passive crossover, i.e. a fine full range driver without everything. And also make sure that there are no components on the ground side, such as coupling capacitors from amplifier outputs;-)
It is more important to understand that the ear perceives differences. These are reconstructed to, for example, "frequencies": frequency mix... Music.
It is not relevant what someone hears 10 years ago or after ten years in terms of frequency response, for example. Someone who only hears 500 Hz - 2 kHz will still hear differences between, for example, parts or circuits;-)
He does hear, he does lsiten;-)
What someone hears is irrelevant, what he perceives counts. I immediately recognize my wife's voice on a cell phone, I don"t have to even think of it. Whether it is a positive leading edge or negative, I cannot tell. It travels through umpteen electronic circuits before reaching me.
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Please let's not drift too far afield, even if the topic of hearing is extremely exciting, especially from an evolutionary perspective. In the present case, with regard to the explanations given, I immediately think of the "Manger transducer" and Josef W. Manger's explanations.
Manger
We all know the practical solution to the (questioned) problem: we simply turn the phase around again.
By the way, the old ReVox A78 is an inverting amplifier, so I swap + with - and vice versa when I connect speakers.
I myself believe (the emphasis is on the belief) that I can make out a change in the sensation, knowing that this is a physical nonsense in the steady state.
HBt.
Manger
We all know the practical solution to the (questioned) problem: we simply turn the phase around again.
By the way, the old ReVox A78 is an inverting amplifier, so I swap + with - and vice versa when I connect speakers.
I myself believe (the emphasis is on the belief) that I can make out a change in the sensation, knowing that this is a physical nonsense in the steady state.
HBt.
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Dozens of circuits and an enormous reduction in frequency response and "dynamics" (loud-quiet) and more:
"Dinner is ready" always arrives;-)
By the way: the "Manger transducer" is a terrible story. It really needs a lot of modification before it produces a clean sound. I once called Manger and told them what they had to do to the driver, after decades of experience the faults should be obvious. They weren't interested. A Gradient AL 160.8, < 30 €, sounds identical, even a bit more pleasant and clearer;-)
Differences;-)
"Dinner is ready" always arrives;-)
By the way: the "Manger transducer" is a terrible story. It really needs a lot of modification before it produces a clean sound. I once called Manger and told them what they had to do to the driver, after decades of experience the faults should be obvious. They weren't interested. A Gradient AL 160.8, < 30 €, sounds identical, even a bit more pleasant and clearer;-)
Differences;-)