What is a tone control?

[Phelonious Ponk]

Hi

Too often simple discussion on Audio takes all the air of a meeting of the Quantum Physics Association. We throw Shroedinger and quantum states here and there ..to finally state in the most grand fashion that we can't measure it all. Which begs the question: If Differences between Cap A and Cap B is consistent .. How did their manufacturers arrived at such differences ... PLease don't tell me "By not measuring" !!????!!
I have no problem accepting that a given cap in a circuit may alter how it sounds .. This has to be measurable if said alteration is consistent ... To me it is simple. If a person want to convince her or himself of the contrary .. I can't change their opinions .. The facts remains that whatever we hear can be measured .. I tend to think that we haven't measured it all but I would say differences must be measurable else they can't be perceived ...
I am with Tomelex here ..

And I'm with Frantz here...

Too often simple discussion on Audio takes all the air of a meeting of the Quantum Physics Association. We throw Shroedinger and quantum states here and there ..to finally state in the most grand fashion that we can't measure it all. Which begs the question: If Differences between Cap A and Cap B is consistent .. How did their manufacturers arrived at such differences ... PLease don't tell me "By not measuring" !!????!!

...and how do the manufacturers that use these caps decide to use them, by listening to every cap that goes into every component during manufacturing and matching them up by ear? Of course not. Demonstrable consistency is required or the design and manufacturing process would become some kind of random improvisational art.

Which of course some would have us believe it is. Sorry, I don't believe. What I believe "I hear what cannot be measured" amounts to more often than not, consciously or otherwise, is an excuse to sell or believe in benefits that do not exist.

Tim

 

[RogerD]

And I'm with Frantz here...



...and how do the manufacturers that use these caps decide to use them, by listening to every cap that goes into every component during manufacturing and matching them up by ear? Of course not. Demonstrable consistency is required or the design and manufacturing process would become some kind of random improvisational art.

Which of course some would have us believe it is. Sorry, I don't believe. What I believe "I hear what cannot be measured" amounts to more often than not, consciously or otherwise, is an excuse to sell or believe in benefits that do not exist.

Tim

I know several manufactures that listen and voice their equipment. They usually find a cap maker that they like and use that brand for years.

 

[Phelonious Ponk]

I know several manufactures that listen and voice their equipment. They usually find a cap maker that they like and use that brand for years.

And if that cap's performance was immeasurable, as you suppose, its quality could not be predicted consistently, and the component manufacturer would have to listen to every cap, every time. And even then, his product would vary according to mood, fatigue, etc., as broadly as our response to our own systems varies daily, even hourly. Somewhere in the design/manufacture process, there has to be some science, some measurable, repeatable standards, or the whole thing just becomes personal tastes and fertile imagination. Which, of course, it often is.

Don't get me wrong or pigeon-hole me. I'm not saying that everything which can be heard has been perfectly measured. But most of it has. So most of this stuff we hear which cannot be measured has got to be us hearing our expectations. Are there exceptions? Sure, I suppose so. But they have to be a tiny, infinitesimal fragment of what is reported in the audiophile community. Thus my skepticism.

Tim

 

[RogerD]

And if that cap's performance was immeasurable, as you suppose, its quality could not be predicted consistently, and the component manufacturer would have to listen to every cap, every time. And even then, his product would vary according to mood, fatigue, etc., as broadly as our response to our own systems varies daily, even hourly. Somewhere in the design/manufacture process, there has to be some science, some measurable, repeatable standards, or the whole thing just becomes personal tastes and fertile imagination. Which, of course, it often is.

Don't get me wrong or pigeon-hole me. I'm not saying that everything which can be heard has been perfectly measured. But most of it has. So most of this stuff we hear which cannot be measured has got to be us hearing our expectations. Are there exceptions? Sure, I suppose so. But they have to be a tiny, infinitesimal fragment of what is reported in the audiophile community. Thus my skepticism.

Tim

So how would one measure noise that rides on the skin of a shielded IC? Then using a ferrite that mitigates that noise. I can hear the difference,but can it be measured.

 

[Phelonious Ponk]

So how would one measure noise that rides on the skin of a shielded IC? Then using a ferrite that mitigates that noise. I can hear the difference,but can it be measured.

I don't much care where it rides, noise doesn't hide in skin effect. If at the business end of that IC you can hear it, it can be measured. In most recordings/systems/rooms, noise, particularly, has to be far above measurable levels to rise above all the stuff that otherwise masks it.

Tim

 

[RogerD]

I don't much care where it rides, noise doesn't hide in skin effect. If at the business end of that IC you can hear it, it can be measured. In most recordings/systems/rooms, noise, particularly, has to be far above measurable levels to rise above all the stuff that otherwise masks it.

Tim

If I read this correctly there is noise created by the antenna effect on shielded cables.

"A common mode signal is one that places equal voltage on all conductors – that is, the voltage between
the two ends of the cable are different, but there is no voltage between the conductors. Antenna
action produces a common mode voltage and current along a cable. The antenna current
induced on audio and video wiring is a common mode signal. That is, with "ideal" cable, there is no
differential voltage between the signal conductors as a result of this antenna action. If the cable is
shielded, nearly all of this current flows on the shield (and skin effect causes it to flow on the outside
of the shield). If the shield is ideal (that is, if the current is distributed with perfect uniformity
around it), the field inside the shield will be zero, and thus none of this antenna current will flow
inside the cable. Conversely, when a cable shield is carrying differential mode current, as in the
case of coax, skin effect will cause that differential mode current to flow on the inside of the shield.
The real world is not ideal, so most interfering signals will simultaneously exist in both common
mode and differential mode, but in most real world conditions, one or the other mode dominates.
Several cable defects (essentially manufacturing tolerances) certainly can and do convert this
"common mode" antenna current to a differential signal (that is, a voltage between the signal conductors),
but that is rarely the most powerful coupling mechanism. One common defect that affects
both balanced and unbalanced cables is imperfect construction of cable shields. In even the
best "real world" balanced twisted pair cables, there are imbalances in the capacitance between
"red" and "black" conductors to the shield on the order of 5%. [B. Whitlock, JAES, June 1995] In
balanced paired cables that use "foil/drain" shields, there is even more imbalance in the inductive
coupling between each conductor and the shield. Noise (or RFI) coupled by this mechanism is
called "shield-current-induced noise," or SCIN. [N. Muncy, JAES, June 1995] All three of these
mechanisms convert shield current to a differential signal at system input and output terminals."

 

[Phelonious Ponk]

If I read this correctly there is noise created by the antenna effect on shielded cables.

"A common mode signal is one that places equal voltage on all conductors – that is, the voltage between
the two ends of the cable are different, but there is no voltage between the conductors. Antenna
action produces a common mode voltage and current along a cable. The antenna current
induced on audio and video wiring is a common mode signal. That is, with "ideal" cable, there is no
differential voltage between the signal conductors as a result of this antenna action. If the cable is
shielded, nearly all of this current flows on the shield (and skin effect causes it to flow on the outside
of the shield). If the shield is ideal (that is, if the current is distributed with perfect uniformity
around it), the field inside the shield will be zero, and thus none of this antenna current will flow
inside the cable. Conversely, when a cable shield is carrying differential mode current, as in the
case of coax, skin effect will cause that differential mode current to flow on the inside of the shield.
The real world is not ideal, so most interfering signals will simultaneously exist in both common
mode and differential mode, but in most real world conditions, one or the other mode dominates.
Several cable defects (essentially manufacturing tolerances) certainly can and do convert this
"common mode" antenna current to a differential signal (that is, a voltage between the signal conductors),
but that is rarely the most powerful coupling mechanism. One common defect that affects
both balanced and unbalanced cables is imperfect construction of cable shields. In even the
best "real world" balanced twisted pair cables, there are imbalances in the capacitance between
"red" and "black" conductors to the shield on the order of 5%. [B. Whitlock, JAES, June 1995] In
balanced paired cables that use "foil/drain" shields, there is even more imbalance in the inductive
coupling between each conductor and the shield. Noise (or RFI) coupled by this mechanism is
called "shield-current-induced noise," or SCIN. [N. Muncy, JAES, June 1995] All three of these
mechanisms convert shield current to a differential signal at system input and output terminals."

Skin effect doesn't have anything to do with the level of noise that I know of. It is a phenomenon in which a part of the signal on a wire gravitates toward the outside, the "skin," of the wire. If the shield is doing its job, the noise is carried on the shield, not the wire. If skin effect impacts that at all, I don't know about it. We may have just gotten above my pay grade. If anything, simple logic would tell me that the shield carrying the noise on its outer surface, further from the wire, is a good thing, theoretically anyway. In any case, none of this has a thing to do with the audibility of the noise, other than the fact that a well-shielded cable will keep some of it out. What it doesn't keep out, what gets to the end of the wire and into the next component, is only audible if it is strong enough to be heard (at least) above your room's ambience. And it is loud enough to be heard over even very quiet ambience, or loud enough to not be masked by the noise created by passive crossovers (sorry...), it is plenty loud enough to be measured. I don't know what you're hearing in ICs that can't be measured, but it isn't noise.

Tim

 

[RogerD]

Skin effect doesn't have anything to do with the level of noise that I know of. It is a phenomenon in which a part of the signal on a wire gravitates toward the outside, the "skin," of the wire. If the shield is doing its job, the noise is carried on the shield, not the wire. If skin effect impacts that at all, I don't know about it. We may have just gotten above my pay grade. If anything, simple logic would tell me that the shield carrying the noise on its outer surface, further from the wire, is a good thing, theoretically anyway. In any case, none of this has a thing to do with the audibility of the noise, other than the fact that a well-shielded cable will keep some of it out. What it doesn't keep out, what gets to the end of the wire and into the next component, is only audible if it is strong enough to be heard (at least) above your room's ambience. And it is loud enough to be heard over even very quiet ambience, or loud enough to not be masked by the noise created by passive crossovers (sorry...), it is plenty loud enough to be measured. I don't know what you're hearing in ICs that can't be measured, but it isn't noise.

Tim

Tim, I misspoke originally, the technical jargon I posted explains it correctly. There must be a device that can measure it, I can hear it as hash or polluting the signal.

I doubt many if few cable manufacturers invest in a measurement device to check this. Can a defect in shielding quality effect the tonal quality of the cable? That's a fine line,but from my ear it does have an effect of what I hear.

 

[RogerD]

Tim,

Here is a response to my question about measurement of RFI/EMI noise by a RKI:

"TYPICAL EQUIPMENT USED TO MEASURE NOISE:




WEIGHTED AUDIO VOLT METER


SPECTRUM ANALYSER


-------------------------------------------------------------------------


WHAT IS THE EXPOSURE AND EFFECT OF RFI AND EMI ON THE EQUIPMENT IN QUESTION?


DIFFERENT EQUIPMENT WILL BE AFFECTED DIFFERENTLY BY RFI AND EMI.


MEASUREMENTS DO NOT RELATE WELL TO WHAT THE EAR PERCEIVES.


MEASUREMENTS DO NOT EXPLAIN WHAT THE EAR PERCEIVES; THIS IS TO SAY, WE DO NOT KNOW WHAT TO MEASURE.


LISTEN AND TRUST YOUR EARS."

 

[Phelonious Ponk]

Can a defect in shielding quality effect the tonal quality of the cable?

Absolutely. There is no "antenna effect" specific to shielding that I'm aware of. The wire itself can act as an antenna, the very purpose of shielding is to take the noise itself and keep it from the wire and, therefore, the component. So yes, a defect in shielding can let noise inl, and that can be heard as a change in tone. No question about it.

That's a fine line,but from my ear it does have an effect of what I hear.

Actually, it's a pretty wide line, and I doubt that's what you're hearing. If it is, as defect would imply, the cable in question is defective and changing to another good quality, well-shielded cable will solve that problem - Belden, Blue Jeans, even a Rocketfish from Best Buy will do - unless you're unlucky enough to get two defective cables in a row.

If what you're hearing is a tonal difference between basic, good quality cable and esoteric, high-end cable, that's something else.

Tim

 

[RogerD]

Absolutely. There is no "antenna effect" specific to shielding that I'm aware of. The wire itself can act as an antenna, the very purpose of shielding is to take the noise itself and keep it from the wire and, therefore, the component. So yes, a defect in shielding can let noise inl, and that can be heard as a change in tone. No question about it.



Actually, it's a pretty wide line, and I doubt that's what you're hearing. If it is, as defect would imply, the cable in question is defective and changing to another good quality, well-shielded cable will solve that problem - Belden, Blue Jeans, even a Rocketfish from Best Buy will do - unless you're unlucky enough to get two defective cables in a row.

If what you're hearing is a tonal difference between basic, good quality cable and esoteric, high-end cable, that's something else.

Tim

My conclusion and this pertains to all cables.

Are a antenna for RFI/EMI

the design of the shield is critical in mitigating RFI/EMI noise

cable manufacturers atleast esoteric one can measure the effects of this noise and build different grades accordingly.

Some use RFI/EMI suppression technology in their cables

 

[Phelonious Ponk]

My conclusion and this pertains to all cables.

Are a antenna for RFI/EMI

Agreed.

the design of the shield is critical in mitigating RFI/EMI noise

Agreed, but there's nothing expensive, difficult or esoteric about it.

cable manufacturers atleast esoteric one can measure the effects of this noise and build different grades accordingly.

Anyone with the instruments can measure the effects of this noise, and anyone who knows how to put a decent cable together can shield one properly.

Some use RFI/EMI suppression technology in their cables

And it's called shielding. If you know about some other RFI/EMI suppression technology, I'm all ears.

Tim

 

[RogerD]

Agreed.



Agreed, but there's nothing expensive, difficult or esoteric about it.



Anyone with the instruments can measure the effects of this noise, and anyone who knows how to put a decent cable together can shield one properly.



And it's called shielding. If you know about some other RFI/EMI suppression technology, I'm all ears.

Tim

Leadertech makes many ferrites in many configuartions for use in manufactured cables. I use both leadertech and Wurth electronics,both have the desired positive effect in mitigating noise.

 

[Phelonious Ponk]

Leadertech makes many ferrites in many configuartions for use in manufactured cables. I use both leadertech and Wurth electronics,both have the desired positive effect in mitigating noise.

Got links? The best way to mitigate noise is to keep it out of the wire in the first place: Shielding. I seriously doubt this RFI/EMI technology, if it is legitimate at all, has any effect on a cable that is well-shielded in the first place. And that would explain why its effects are immeasurable. Sounds a lot like Audioquest's "long grain copper," which is purported to transmit the signal without the additional noise created by the electrons leaping across the gaps created by short grain copper. Google long grain copper. You'll find no references to any such thing, or the adverse effects of "short grain copper" anywhere outside of Audioquest's marketing literature. Caveat emptor.

Tim

Tim

 

[RogerD]

Got links? The best way to mitigate noise is to keep it out of the wire in the first place: Shielding. I seriously doubt this RFI/EMI technology, if it is legitimate at all, has any effect on a cable that is well-shielded in the first place. And that would explain why its effects are immeasurable. Sounds a lot like Audioquest's "long grain copper," which is purported to transmit the signal without the additional noise created by the electrons leaping across the gaps created by short grain copper. Google long grain copper. You'll find no references to any such thing, or the adverse effects of "short grain copper" anywhere outside of Audioquest's marketing literature. Caveat emptor.

Tim

Tim

C'mon Tim get out of the box. I opened the door now go thru it.

 

[microstrip]

And if that cap's performance was immeasurable, as you suppose, its quality could not be predicted consistently, and the component manufacturer would have to listen to every cap, every time. And even then, his product would vary according to mood, fatigue, etc., as broadly as our response to our own systems varies daily, even hourly. Somewhere in the design/manufacture process, there has to be some science, some measurable, repeatable standards, or the whole thing just becomes personal tastes and fertile imagination. Which, of course, it often is.

Don't get me wrong or pigeon-hole me. I'm not saying that everything which can be heard has been perfectly measured. But most of it has. So most of this stuff we hear which cannot be measured has got to be us hearing our expectations. Are there exceptions? Sure, I suppose so. But they have to be a tiny, infinitesimal fragment of what is reported in the audiophile community. Thus my skepticism.

Tim

Tim,
Sorry, but it seems you are mixing component performance and the performance of audio equipment using these components. These are completely different things. There are many parameters to evaluate capacitors, not audio related, and component manufacturers use them for development and ,as you say, to check quality and production consistency. Most components used in audio were not developed for audio and are not tested with audio measurements.

An audio designer will evaluate many capacitors in different ways - audition in his designs, measurements and will choose some he prefers for same reasons we can not be sure. Then, as Roger wisely says, may be he will stick with them, as in his belief they are synergistic with his design intentions, or just because since he had the work to define some custom models and make some non trivial measurements he wants to make use of his acquired intellectual capital. I was guessing, I have no proof of it!

But all of us that do not have access to this classified information must rely only on our hears. You can be skeptical about audiophile claims, and I respect it, but as the other side also does not show openly their hidden cards, it is a skeptics debate from both sides.

 

[Phelonious Ponk]

C'mon Tim get out of the box. I opened the door now go thru it.

The problem, Rich, is that the box I'm in is built of data and logic. Any metal wire will act as an antenna. The way to stop it is to wrap it in another metal that takes that RFI/EMI before it can get to the operative wire, shielding the wire from the problem, then carries it to ground, keeping the noise from getting in the circuit. It's pretty fundamental stuff. The other part of the discussion is noise. If something gets past the shield to the wire and becomes noise in the system, if it is loud enough to hear over the noise in all the caps and resistors in your crossovers, if it is loud enough to hear over the ambient noise of even a very quiet room, it is measurable. You left the door open. Come on in. It makes sense in here.



Tim

 

[RogerD]

The problem, Rich, is that the box I'm in is built of data and logic. Any metal wire will act as an antenna. The way to stop it is to wrap it in another metal that takes that RFI/EMI before it can get to the operative wire, shielding the wire from the problem, then carries it to ground, keeping the noise from getting in the circuit. It's pretty fundamental stuff. The other part of the discussion is noise. If something gets past the shield to the wire and becomes noise in the system, if it is loud enough to hear over the noise in all the caps and resistors in your crossovers, if it is loud enough to hear over the ambient noise of even a very quiet room, it is measurable. You left the door open. Come on in. It makes sense in here.



Tim

Well, I'm not going to get you convinced, I can tell that. If Neil Muncy says that SCIN exists I'll believe him and my own ears. Ferrites have been around for years,just not well known in the high end community. I can see why too, there's way too much money to be made with the status quo. Depending on your system and cabling in place about 200.00 to a 300.00 investment would turn you into a true believer. The reason I like to talk about it is that, it's so much bang for the buck,it is amazing,and the degree of improvement is off the chart.

 

[Phelonious Ponk]

The reason I like to talk about it is that, it's so much bang for the buck,it is amazing,and the degree of improvement is off the chart.

Again, if it's that big a change (or a whole lot less), it's measurable, which is, sort of, what off the charts means. Have Neil Muncey and/or SCIN (whoever they are...) supported their claims with any data? No, I didn't think so...

Tim

 

[mep]

My first run-in with EMI/RFI was when I lived in Maine and had a pair of interconnects from Kimber that were unshielded. It was a long run from my Counterpoint SA-5.1 to my ARC D-76. The Kimber interconnects were acting as an antenna and I could clearly hear a radio station playing through my system.