cracked case,
Nice post!
You have landed on a very interesting difference between Some single ended amps, and Some push pull amps.
For this discussion:
We will not use negative feedback.
We will limit the single ended amp to its proper Class A output (tube never goes into cutoff).
We will also limit the push pull amp to Class A (neither tube ever goes into cutoff).
If we send a sine wave test tone to both amplifiers . . .
1. The plate impedance of the single ended output tube varies as the tube ranges from low plate current (high plate impedance),
to high plate current (low plate impedance).
That means the Damping Factor that the loudspeaker is driven by, varies with the signal amplitude and polarity.
The single ended output characteristic is Un-Symmetrical Damping Factor.
Decades ago, I noticed an effect when using single ended amps, called "Woofer Walk": the average position of the vibrating woofer cone moves away from the at-rest center position of the cone.
When the damping factor is less, the cone is electrically less dampened; and when the damping factor is more, the cone is electrically more dampened. That is the cause of the "Woofer Walk".
2. The plate impedances of the push pull tubes varies with signal.
However, as one tube's plate is conducting less current (higher impedance); the other tube's plate is conducting more current (lower impedance).
The push pull output characteristic is Symmetrical Damping Factor.
That results in equal damping factors for both directions of the cone movement; the result is No "Woofer Walk".
3. I am Happy to give credit to Lynn Olson __ for pointing out to me, the symmetrical damping factor of push pull amps.
Have Fun!
Nice post!
You have landed on a very interesting difference between Some single ended amps, and Some push pull amps.
For this discussion:
We will not use negative feedback.
We will limit the single ended amp to its proper Class A output (tube never goes into cutoff).
We will also limit the push pull amp to Class A (neither tube ever goes into cutoff).
If we send a sine wave test tone to both amplifiers . . .
1. The plate impedance of the single ended output tube varies as the tube ranges from low plate current (high plate impedance),
to high plate current (low plate impedance).
That means the Damping Factor that the loudspeaker is driven by, varies with the signal amplitude and polarity.
The single ended output characteristic is Un-Symmetrical Damping Factor.
Decades ago, I noticed an effect when using single ended amps, called "Woofer Walk": the average position of the vibrating woofer cone moves away from the at-rest center position of the cone.
When the damping factor is less, the cone is electrically less dampened; and when the damping factor is more, the cone is electrically more dampened. That is the cause of the "Woofer Walk".
2. The plate impedances of the push pull tubes varies with signal.
However, as one tube's plate is conducting less current (higher impedance); the other tube's plate is conducting more current (lower impedance).
The push pull output characteristic is Symmetrical Damping Factor.
That results in equal damping factors for both directions of the cone movement; the result is No "Woofer Walk".
3. I am Happy to give credit to Lynn Olson __ for pointing out to me, the symmetrical damping factor of push pull amps.
Have Fun!
The ear, hearing: no dipole microphone or anything like that, a micro in a closed housing with minimal leakage;-?
Yes, probably yes and I haven't ruled it out at all. 🙂
However, may be that sometimes I may seems a bit "picky" (I don't know if here this word is really appropriate in English) even because I believe that regarding the Physiology of Hearing sometimes small differences in a description can make a big difference in the risk of misinterpretation of our concept and/or our knowledge.
The above is probably due to my job since it consists of presenting scientific topics to an audience of doctors (physician and surgeons), then for obvious reasons I can't afford to make mistakes of any kind.
By the way, thanks to (and even if it's not related to) your appreciated reply, I just remembered that I already posted something about the fact that the Propagation of Sound does not make the air move (in the common sense of moving) a long time ago...
https://www.diyaudio.com/community/...field-with-2-way-speakers.390217/post-7121815
Where, however, there is a translation error relating to the fact that I wanted to say: "a billionth of a millimetre" instead of "billion of a millimeter". 😉
I assume "of pression", so yes, in physiology it is self-regulated and only if/when needed.
Some pathologies interfere with the pressure inside the middle ear and distort the way "how" those patients hear.
Consider a woofer cone that has a high frequency Gaussian response bandwidth of 70Hz (0.5 millisecond rise time).
If the cone gets a fast rise signal that moves it into the room: 1mm in 0.5 millisecond, then what happens?
A. Does the cone act on all the air molecules that are bouncing on that cone, and on the average, move them forward 1mm?
Or,
B. Do the air molecules still bounce, but on the average "stay in place", while the cone "opens up" and lets the bouncing air molecules on the average stay stationary, while the forward moving cone moves over those air molecules on the cones path of a 1mm displacement.
I am just asking if there is any air "movement", air "flow", or 'whatever name' you wish to call it.
On the average, I am running in place until I get a satisfactory answer, than I can "move" forward again, or "flow" forward through life again.
I do not know how many air molecules are in a volume equivalent to 1mm of displacement times a 12 inch diameter cone.
I bet it is a very large quantity.
Just my wacky way that I look at things.
If the cone gets a fast rise signal that moves it into the room: 1mm in 0.5 millisecond, then what happens?
A. Does the cone act on all the air molecules that are bouncing on that cone, and on the average, move them forward 1mm?
Or,
B. Do the air molecules still bounce, but on the average "stay in place", while the cone "opens up" and lets the bouncing air molecules on the average stay stationary, while the forward moving cone moves over those air molecules on the cones path of a 1mm displacement.
I am just asking if there is any air "movement", air "flow", or 'whatever name' you wish to call it.
On the average, I am running in place until I get a satisfactory answer, than I can "move" forward again, or "flow" forward through life again.
I do not know how many air molecules are in a volume equivalent to 1mm of displacement times a 12 inch diameter cone.
I bet it is a very large quantity.
Just my wacky way that I look at things.
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On this same Forum - which I remind you all is the most important Audio Forum in the world - there are many Electronic Engineers who post their wisdom and everyone seems fascinated by it and no one allows themselves to say bs both because he knows nothing about electronic engineering and so as not to look like a presumptuous/stupid/arrogant challenging what he knows just nothing about.
Yet it's just electronic engineering: one goes to school, studies and learns.
However, when it comes to the Science of Sound Propagation, anyone seems to think that he can say any BS with impunity without realizing that he is making himrself look not only ignorant but also very very very presumptuous.
Even medical scientific publications are denied.
And all this happens on the most important Audio Forum in the world...
Yet it's just electronic engineering: one goes to school, studies and learns.
However, when it comes to the Science of Sound Propagation, anyone seems to think that he can say any BS with impunity without realizing that he is making himrself look not only ignorant but also very very very presumptuous.
Even medical scientific publications are denied.
And all this happens on the most important Audio Forum in the world...
A Joseph Manger has developed a driver, which he calls "Biege-wellen-wandler": "bending wave transducer". He wanted to functionally adapt the loudspeaker membrane to the eardrum. But an eardrum is also a pressure membrane. Below 200 Hertz, however, this Manger driver pushes and sucks the medium air classically. It may well be that we first of all have an excitation of the medium in different ways. The sound propagation can be just as different - if we interpret pressure changes in frequency as sound.
Or do we even have a distinction, shift relating to frequencies - and materials and more;-?
Aside: this Manger driver does not sound as good as promised or claimed. As example, a Gradient W 160 AL 8 sounds tonally identical, and seems somewhat more lively and genuine: material, construction, transient response and decay...-)
Or do we even have a distinction, shift relating to frequencies - and materials and more;-?
Aside: this Manger driver does not sound as good as promised or claimed. As example, a Gradient W 160 AL 8 sounds tonally identical, and seems somewhat more lively and genuine: material, construction, transient response and decay...-)
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Do you ask things that are almost impossible to answer to me?
If affirmative then you should ask whoever invented what you describe, not me.
I don't know much, I know little.
But what little I know, I know that I know.
Physics can be updated, but there are things that don't change.
Propagation of Sound is one of them.
Sound is generated as a vibration (it is not movement, it is vibration), the sound transmits that vibration to the air (it is not movement, it is vibration) and the air transmits that same vibration to the ear, or rather to the tympanic membrane (it's not movement, it's vibration).
The vibration of the eardrum (it is not movement, it is vibration) is then transmitted to the malleus (hammer) as vibration, not as movement, and consequently to the other two ossicles which everyone will be kind enough to go and see what they are called.
Sound propagation is all vibration and no movement.
If affirmative then you should ask whoever invented what you describe, not me.
I don't know much, I know little.
But what little I know, I know that I know.
Physics can be updated, but there are things that don't change.
Propagation of Sound is one of them.
The wonderful thing is that about ear and hearing everything works in a totally analogue way (of course).
Sound is generated as a vibration (it is not movement, it is vibration), the sound transmits that vibration to the air (it is not movement, it is vibration) and the air transmits that same vibration to the ear, or rather to the tympanic membrane (it's not movement, it's vibration).
The vibration of the eardrum (it is not movement, it is vibration) is then transmitted to the malleus (hammer) as vibration, not as movement, and consequently to the other two ossicles which everyone will be kind enough to go and see what they are called.
Sound propagation is all vibration and no movement.
Hi 6A3sUMMER,
Assuming you were asking me too: no, there is no air movement.
There is "only" the vibration of the air molecules.
Vibration, not movement.
And it's the same for the eardrum: the eardrum vibrates, it doesn't move in the meaning one gives to the verb.
Sound is all vibrations.
I don't say it, I just studied and learned it. 😉
I guess you still don't believe me, then let's do an experiment together, please follow me in the following reasoning, okay?
The tuned woofer in bass-reflex is just a way of loading the operation of the woofer in accordance with certain of its technical characteristics and has nothing to do with the propagation of sound: that is a technical expedient to get some performance from a woofer.
A woofer, let's not forget it, is just a man-made object, not a thing created by Nature.
If you don't believe it, forget about tuned systems and get any pneumatic suspension subwoofer with at least one woofer of any diameter: do you like if let's say 45 cm?
Now play that subwoofer plugged into any system and play
J. S. Bach - Toccata & Fugue in D Minor
The Organs of Los Angeles First Congregational Church
by Michael Murray
I think that majestic pipe organ can go easily beyond 16 Hz.
Play it, you like it if let's with 500W per channel amp (but obviously any other power would be fine, as this is just an example).
Now you will see the woofer diaphragm of the subwoofer going back and forth wildly with the suspension moving back and forth even more than 1 centimeter.
Now place a hair, a small piece of tissue paper or very light silk, or the lightest and most "movable" thing you can imagine and fix it, but free to float, to a solid pedestal right in front of that 45 cm woofer, a few centimeters from its diaphragm right in front of that woofer that is moving wildly.
Observe carefully whether the hair or the small sheet of tissue paper or silk o whatever you want moves even by just a micron.
It moves?
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There needs to be pressure and movement of the sound through the air. Regardless of how it’s achieved, that’s what you’ll see. Your primary differences will be where and when it appears.
I also understand movement as frequency: Spacing/ tact.
Movenment and vibration are concepts. And, at moment, we presuppose objects: particles.
The question is also with regard to "ether", for example. Are ether "particles" moved in relation to each other, in their spacings, or does a transfer of "information" occur through, for example, rotation of these particles, "magnetically bound". In the case of sound, do we have a movement of "particles" towards each other or a movement of the particles, e.g. rotation?
Movenment and vibration are concepts. And, at moment, we presuppose objects: particles.
The question is also with regard to "ether", for example. Are ether "particles" moved in relation to each other, in their spacings, or does a transfer of "information" occur through, for example, rotation of these particles, "magnetically bound". In the case of sound, do we have a movement of "particles" towards each other or a movement of the particles, e.g. rotation?
Please, if you are really interested in this topic, why do I have the feeling that you haven't read anything about it or even the two links I posted previously?
They are scientific publications, not exactly bs, and what you ask is just explained.
Or go and look on the Internet for your information on sites that you consider reliable, with all the friendship I'll tell you the above. 🙂
However, once again, you don't necessarily have to think about propagation of the sound in the air, you could think about water or a metal, for example as transmission medium.
How does metal sound when struck?
Do you think metal molecules move?
No, they don't move, they vibrate.
Vibration and movement may be two concepts, but they explain the Physics.
If you manipulate reality according to your uncertainties (which are also legitimate) here, no one will be able to follow you in any reasoning.
This is about Physics and Medicine/Otorhinolaryngology, not philosophy.
It should be studied, not questioned. 😉
Please note I've the utmost respect for Philosophy.
What does vibration mean? Movement?
A passive diaphragm of a subwoofer-box would not be moved by a woofer. And a moving woofer cone would not push air through a bass reflex tube. (And "a hair, a small piece of tissue paper or very light silk, or the lightest and most "movable" thing you can imagine and fix" would neither be moved in the tube nor longer be moved with increasing distance from the tube: the air particles are no longer bundled and directed.)
And likewise, the cone of a woofer would not be moved, in frequency, by a flow of "electrons", "motion" in frequency, which induces a material in a magnetic field to move, in frequency.
A string vibrates when it is moved: objects are in motion in relation to each other. This is also visible.
I think we have just different concepts of vibration and movement. Or also of medium: medium consisting of many objects that can also avoid each other, or medium as a compact solid block that is in "one" motion.
A passive diaphragm of a subwoofer-box would not be moved by a woofer. And a moving woofer cone would not push air through a bass reflex tube. (And "a hair, a small piece of tissue paper or very light silk, or the lightest and most "movable" thing you can imagine and fix" would neither be moved in the tube nor longer be moved with increasing distance from the tube: the air particles are no longer bundled and directed.)
And likewise, the cone of a woofer would not be moved, in frequency, by a flow of "electrons", "motion" in frequency, which induces a material in a magnetic field to move, in frequency.
A string vibrates when it is moved: objects are in motion in relation to each other. This is also visible.
I think we have just different concepts of vibration and movement. Or also of medium: medium consisting of many objects that can also avoid each other, or medium as a compact solid block that is in "one" motion.
I think I've got it: your definition of vibration is back-and-forth movement. And your movement is directed movement.
And many others, like me, also see a back-and-forth movement as movement. And the frequency, the sequence, the "vibration" - of a movement -, is defined by back and forth.
Like this?
And many others, like me, also see a back-and-forth movement as movement. And the frequency, the sequence, the "vibration" - of a movement -, is defined by back and forth.
Like this?
You seem as stubborn as a mule: that's not my definition!!!
However, are you okay with the definition disclosed (because someone didn't invent it!) by Princeton University?
https://assets.press.princeton.edu/chapters/s9912.pdf
But you have to promise that you will actually read it!
Also because it is university material protected by copyright and I couldn't transcribe it here even if I wanted to. 😉
P. S.: Trust me, the one linked above is an exceptional document that would really be worth studying seriously and carefully by anyone if only for general knowledge. 🙂
I followed you here, but up to a certain point.
You must be a rather "aerial mind" type because you like to question yourself first and foremost and everything you know, if you know it and if you don't.
Interesting, for me.
I would like to talk to you closely and with the same native language; I think we could even have a lot of fun.
But here, on a forum, in a non-native language, I can't do it.
And I'm so sorry about that. 🙂