Has anyone done a back-of-envelope estimate of how large the source impedance has to be before any such effect might become noticeable? I can believe that there could be medium-term relaxation phenomena in dielectrics, but I find it harder to believe that it could be apparent in a typical audio system.fas42 said:
Note that medical cables are probably for sensing low voltages at fairly high impedances, which is rather different from audio interconnects.
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Of course, this has to do with cable used with medical equipment, where accuracy and lack of spurious input is important; unlike audio where it is quite irrelevant,,
Apparently it is, since audiophiles like to use Teflon and silver, which is one of the worst possible combinations for triboelectric effects.
Tell me about it!! This is classic audio electronics stabilising behaviour, I've lived with and become completely accustomed to this "cycle" of behaviour over many, many years -- to some degree this is because the various processes of stabilisation have different timelines -- the materials involved and the mechanisms all differ, so in one sense it can't be any other way.
My current setup needs about 5 hours from a cold startup to really hit its straps; at certain points it sounds quite pathetic, and pretty disagreeable ...
Frank
An alternative viewpoint on speaker wiring in ordinary living rooms is that they are much, much too short to be transmission lines (in the sense of being terminatable in a characteristic impedance to look like a resistor to the amplifier). In practical lengths and for practical amplifiers, speaker wiring is mostly just a lumped capacitance. Food for thought.
Thanks,
Chris
Thanks,
Chris
The science of dielectrics is very very complicated - I think you might need a large envelope
Not to mention the science of electron flow in metals in different states of fatigue & oxidization etc.
Not easy for a quick listening
Don't you address the effect to be more in relation whith caps and silicon parts changing (and equalizing) values (Z and hfe) with temp (what we can measure) ?
Any oscillating problem near the edge ? Because, if i can understand a slight difference, runnig from disagreeable to very good is, at least, strange.
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Have you managed to fool a professional musician, entering your room blindfolded, to think he/she attended live concert?
Since I listen primarily to classical music, I'm not sure what you are talking about.
Anyhow, it seems to me that the term 'musical setup' is a personal one, different people will not always agree about the degree of 'musicality' of a certain setup. I've seen a person defining 'musical setup' as unbalanced one.
Part of the problem is that "cheap" parts are used, it's just a Philips consumer item, even though it's far better made than the current equivalent. The speaker drivers are a major factor, pretty nothing suspensions, and they have to be driven hard for some time to fully loosen up.Not easy for a quick listening
Don't you address the effect to be more in relation whith caps and silicon parts changing (and equalizing) values (Z and hfe) with temp (what we can measure) ?
Any oscillating problem near the edge ? Because, if i can understand a slight difference, runnig from disagreeable to very good is, at least, strange.
If I knew all the answers, I'd probably be a millionaire!! Yes, cheap electros need to come on line, the DAC area is stinking with the little blighters, which means the treble sounds totally dead when first switched on.
"Disagreeable" is in the area of difficult recordings sounding harsh, cluttered, shouty; a "good" recording is not a problem. Basically, enough of the acoustic gremlins have to drop in level to become relatively inaudible, so that the ear/brain can do its job of sifting out the unpleasant detail. It is remarkable how seamlessly and quickly the sound can go from "disagreeable" to "magic"; unfortunately, it can go just as easily the other way. I've been pulling my hair out over the years trying to understand the subtle factors involved; it is not an easy journey ...
Frank
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It will be 6 Ohms at 100 kHz for sure.
At 50 kHz, near 6 Ohms maybe.
But at 50 Hz not a chance of it being anywhere near 6 Ohms!
The only way to come close to 6 Ohm speaker cable is to do something strange like the Dynaudio OCOS Speaker Cable.
There are some interconnects that, given suitably high-Z source impedance, can generate audible microphonics: the Audioquest ones that come with little batteries to "polarize" the dielectric. I tested some, acquired from the company by a previous associate in a switchmode amp company. Thank goodness they were at a deep discount, as I regarded them with suspicion and disdain. There are good reasons why four of us in the nascent corporation abruptly left the remaining two people!
The science of dielectrics is very very complicated - I think you might need a large envelope
Not to mention the science of electron flow in metals in different states of fatigue & oxidization etc.
Sigh!
we have returned to audio as the great watershed application. If you try hard enough you can find this entry point into this thread in the past. These statements sound nice but can YOU shed any technical insight (especially on the second one).I've done this stuff for 40yrs., published numerous data sheets and applications notes, and designed electrometers and other ultra-high impedance circuitry and I will say unequivocably most of the stuff published abut dielectrics and audio is ca-ca.
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Would be pretty hard to set that one up ...
! Might do it with solo instrument, like Spanish guitar; the musician could conceive that there just happened to be a good player in your home. One cute "trick": my wife's daughter, trained many years on the piano, rings up and a number of times has said, who's playing your piano, in the other room? Of course, only dealing with low grade phone link, but the reproduction is triggering the right acoustic clues from reflections in that room to convey the sense of a real instrument being played ...
With classical, it can be about the fine detail still being discernable in a climax, say the texture of the choral voices at the end of Beethoven's 9th. Massed strings create a certain ambience, a texture "in the air" for me, there's a quality like rich honey about it; if this is fully, satisfyingly reproduced then I feel good progress has been made.
Frank
No one's stopping you, though as usual, expect nonsense to be called such.
Kgrlee,
I wasn't avoiding your questions but for some reason the link to this thread stopped giving me updates that were coming in.
As to your question about the cone mass that I was talking about perhaps because of the manufacturing method and materials I can do something that others can not. Paper cones are made with a slush molding process and I doubt very much that this process can be controlled at a very high precision. Most other composite cones use a polypropylene binder resin and the way that the resin is infused is again somewhat but fairly well controlled. I originally developed my cone material as a challenge from a friend who was working with DuPont on a new composite cone material for a new speaker application. They could not with the electrostatic process they were using to combine the polypro and carbon fiber and the high pressure compression molding process they were using make two cones that weighed anywhere near the same and there were more problems than improvements between devices. So I took the challenge and developed a new material and manufacturing method. Another patent to apply for..... By the 11th cone variation that I made I had far surpassed the acoustical properties of the DuPont material. That was the end of the Dupont material that I know of. The real problem with the cone assembly with the separate parts I have had has been more to do with the adhesive dispensing and weight control than anything to do with the cone itself. Dispensing an exact amount of adhesive is far harder to control than the cone weight. It gets to be like trying to match two transistors with two exactly the same even with today's manufacturing methods and quality controls. 6sigma is part of most manufacturing these days and I would think the same in electronic production.
I wasn't avoiding your questions but for some reason the link to this thread stopped giving me updates that were coming in.
As to your question about the cone mass that I was talking about perhaps because of the manufacturing method and materials I can do something that others can not. Paper cones are made with a slush molding process and I doubt very much that this process can be controlled at a very high precision. Most other composite cones use a polypropylene binder resin and the way that the resin is infused is again somewhat but fairly well controlled. I originally developed my cone material as a challenge from a friend who was working with DuPont on a new composite cone material for a new speaker application. They could not with the electrostatic process they were using to combine the polypro and carbon fiber and the high pressure compression molding process they were using make two cones that weighed anywhere near the same and there were more problems than improvements between devices. So I took the challenge and developed a new material and manufacturing method. Another patent to apply for..... By the 11th cone variation that I made I had far surpassed the acoustical properties of the DuPont material. That was the end of the Dupont material that I know of. The real problem with the cone assembly with the separate parts I have had has been more to do with the adhesive dispensing and weight control than anything to do with the cone itself. Dispensing an exact amount of adhesive is far harder to control than the cone weight. It gets to be like trying to match two transistors with two exactly the same even with today's manufacturing methods and quality controls. 6sigma is part of most manufacturing these days and I would think the same in electronic production.
For those discussing interconnects and the change over time I have an idea about some of what could possibly be happening there but no proof of my theory. Any flexible plastic typically has additive added to give specific processing and physical properties. We all know of Phathalates that are added to polycarbonate plastic and other plastics to make them flexible. This material is able to migrate in the plastic, sort of like the film on the glass on the inside of a car when it is new on a hot day. Those are the plasticizers that are added to the vinyl so it does not crack the first time you touch or hit it. Could it be that the plasticizers are migrating out of the insulation and changing the capacitive properties of the wires? Just an idea that I have been thinking about.
Off to dinner and be back to see what anyone else thinks of this theory.
Steven
Off to dinner and be back to see what anyone else thinks of this theory.
Steven
The thing is, there is something there having an effect, and, yes, the majority written about these areas is total BS, but that shouldn't then imply that there is absolutely nothing in this field that doesn't have ramifications for sound quality. Just because a particular person doesn't have at this point of time a valid, scientific explanation for precisely what is occurring, that the sequence of cause and effect is not fully understandable, doesn't then invalidate the phenomenon.
Personally, I believe that everyday, well understood interactions can explain it all, but the right level of expertise and genuine interest and desire to get to the bottom of things has to be brought to bear upon it ...
Frank
Yep, this does work. 3D life like audio jumping out of the speakers. I tried to grab the notes as they flew through the air once.
Highly improbable. First, phthalates are almost never present in polycarbonate except in microscopic quantities as an impurity from certain types of catalyst used to manufacture the raw resins (parts per billion). They are, however, used in vinyl. I can't think of any other flexible plastic which uses them.
Second, the time scale for migration is hours to days, not milliseconds.
Third, their migration is driven by concentration gradients, not electric fields.
Fourth... well... you get the idea.
edit: I goofed. The trace impurities of phthalates are in polypropylene, not polycarbonate. Polycarbonate is a condensation polymer from BPA and phosgene. Zero phthalates. Sorry about the inaccuracy.
I'm very uncomfortable with this cable sound story.
I was deeply interested by this question, decades ago.
I had made a lot of listening, and spend a long time to thing about when this cable's fashion arrived in the audiophile place. And to measure.
My problem is i was unable to constat any strange behavior that i cannot address (or reproduce) with pure Z explanations: effects of charges reactance, amp side, response curves due to impedance and damping, enclosure side.
I had made comparisons between very short big wires, and different long cables with the help of a seller...
Then simulation of the long cables with caps and resistances, and comparisons again.
I don't believe any more in some special metal or insulation material behavior.
If any little mystery remain, i' was not sure it was not a pure illusion from my brain, as it was about so little difference that i have a lot of things i would like to improve in my system, *before* to put again my attention (and my money) on it.
I was deeply interested by this question, decades ago.
I had made a lot of listening, and spend a long time to thing about when this cable's fashion arrived in the audiophile place. And to measure.
My problem is i was unable to constat any strange behavior that i cannot address (or reproduce) with pure Z explanations: effects of charges reactance, amp side, response curves due to impedance and damping, enclosure side.
I had made comparisons between very short big wires, and different long cables with the help of a seller...
Then simulation of the long cables with caps and resistances, and comparisons again.
I don't believe any more in some special metal or insulation material behavior.
If any little mystery remain, i' was not sure it was not a pure illusion from my brain, as it was about so little difference that i have a lot of things i would like to improve in my system, *before* to put again my attention (and my money) on it.
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