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post #61 of 67

Actually surface oxidation can change electrical properties of a cable.  When you chemically change a substance to a different one, it changes properties entirely (including electrical).  I don't know if rust is a good conductor or even verdigris for that matter, however, the exterior of the cable changes into verdigris (that much is confirmed), but we don't know how deep the surface goes.  It may be variable.  This changes the crossectional area of the cable, thus changing resistance due to this equation:

 

R = p (l/A)

 

-R = electrical resistance

-p = Resistance constant for the certain material (normally shown by the Greek rho symbol, but a p looks similar to the rho).

-l = length of the cable/metal/material.

-A = crosssectional area of the metal/cable/material

 

When the A is decreased (due to the surface changing), the resistance goes up.  Depending on how deep the reactions go, your resistance gained may vary.  I don't see this change being that great though (not audible at all unless you go through some sort of advanced oxidation that tears through the cable; then you have other things to worry about). 

 

Although the electrical properties of the material have been changed slightly, I don't see it being a big enough change to hear sonically.  It does change though.

post #62 of 67

Does not conduct because electrons are not on the conduction band.

 

http://en.wikipedia.org/wiki/Electronic_band_structure
 

Quote:
Originally Posted by tinyman392 View Post

Actually surface oxidation can change electrical properties of a cable.  When you chemically change a substance to a different one, it changes properties entirely (including electrical).  I don't know if rust is a good conductor or even verdigris for that matter, however, the exterior of the cable changes into verdigris (that much is confirmed), but we don't know how deep the surface goes.  It may be variable.  This changes the crossectional area of the cable, thus changing resistance due to this equation:

 

R = p (l/A)

 

-R = electrical resistance

-p = Resistance constant for the certain material (normally shown by the Greek rho symbol, but a p looks similar to the rho).

-l = length of the cable/metal/material.

-A = crosssectional area of the metal/cable/material

 

When the A is decreased (due to the surface changing), the resistance goes up.  Depending on how deep the reactions go, your resistance gained may vary.  I don't see this change being that great though (not audible at all unless you go through some sort of advanced oxidation that tears through the cable; then you have other things to worry about). 

 

Although the electrical properties of the material have been changed slightly, I don't see it being a big enough change to hear sonically.  It does change though.



 

post #63 of 67
Quote:
Originally Posted by High_Q View Post

Does not conduct because electrons are not on the conduction band.

 

http://en.wikipedia.org/wiki/Electronic_band_structure
 



 


OK, thanks.  Do you have a degree in physics (It sounds like you do), and what branch if you do (I'm just curious :p)?

 

post #64 of 67

I have a degree in EE.  In order to obtain an EE degree, you must have Calculus based Physics background, and basic level of Chemistry.  EE covers many disciplines such as Power electronics, Wireless communications, Analog circuitry, Digital circuitry, Signal processing, Semiconductors.  So an EE may know a lot about Power electronics, and may have weak Signal processing back ground.  What you know, depends on what you focus on.  Like any other Engineering disciplines, teachings are heavy on theory(maybe part of weed out process), and some practical learning.  Most think theories are useless, but without it, you cannot have much deeper understanding, and it speeds up how quickly you can learn things related to the theory.  I have taken a class on semiconductors, and topics of conduction, and how electrons behave in the particle level are taught very precisely.  My school has long history with semiconductors and transistors(John Bardeen), and it is the most difficult class to pass.  If you ever taken that course, you will have an idea of how much we know about how electron behaves.  And we know a lot.  That's just Bachelor's level, who knows what kind of crazy research is be done at the grad schools.  While attending engineering school, I realized nothing is impossible and we know a lot.


Edited by High_Q - 7/10/11 at 11:41pm
post #65 of 67

Oh, OK, it sounded like you knew stuff (especially when you pulled random, well not really random, Wiki articles out of nowhere) :p

 

I'm just starting to go to school now...  CS, nothing special.


Edited by tinyman392 - 7/10/11 at 11:36pm
post #66 of 67
Quote:
Originally Posted by tinyman392 View Post

Actually surface oxidation can change electrical properties of a cable.  When you chemically change a substance to a different one, it changes properties entirely (including electrical).  I don't know if rust is a good conductor or even verdigris for that matter, however, the exterior of the cable changes into verdigris (that much is confirmed), but we don't know how deep the surface goes.  It may be variable.  This changes the crossectional area of the cable, thus changing resistance due to this equation:

 

R = p (l/A)

 

-R = electrical resistance

-p = Resistance constant for the certain material (normally shown by the Greek rho symbol, but a p looks similar to the rho).

-l = length of the cable/metal/material.

-A = crosssectional area of the metal/cable/material

 

When the A is decreased (due to the surface changing), the resistance goes up.  Depending on how deep the reactions go, your resistance gained may vary.  I don't see this change being that great though (not audible at all unless you go through some sort of advanced oxidation that tears through the cable; then you have other things to worry about). 

 

Although the electrical properties of the material have been changed slightly, I don't see it being a big enough change to hear sonically.  It does change though.


Thank you, you got exactly my point. And I don't have an EE degree (sorry, I had to), but I'm in biochemistry. I'm not sure if this is what happens, but I suppose the copper carbonate (verdigris) doesn't release electrons the way pure copper does, and it's just a much worse conductor. And I'm not saying this reflects deeply on the sound, just don't say the cable is just the same because it isn't - it's chemically different, and its conductive properties aren't the same. And since I'm not going for Steampunk IEMs, I don't really want them to look like that anyway tongue.gif

post #67 of 67

I solved the issue.  No worries guys. Its just the shielding material greening, not the conductive cables themselves. I also would like to believe that the greening often always happens near the earpieces not because it makes most contact with skin and skin oil from the ears but...  because there will be some air that will diffuse into the cables from the openings of the IEM driver housing. Once there is a cut like this the whole cable turns green because oxygen gets into everywhere. I guess that means no more OFC :)

 

 

 

Earphones 2.jpg


Edited by wilzc - 9/15/11 at 9:19pm
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