Can voltage cause molecules to move and is it related to 'burn-in'?

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Discussion Overview

The discussion centers around the concept of "burn-in" for audio cables, specifically whether applying a voltage can cause molecular movement within the cables and if this relates to perceived changes in audio quality over time. Participants explore the physics behind these claims, including the effects of electric fields on materials, the role of electrons, and the validity of the burn-in phenomenon.

Discussion Character

  • Debate/contested
  • Technical explanation
  • Conceptual clarification

Main Points Raised

  • Some participants propose that applying a voltage gradient can cause molecules in the dielectric material of cables to move and potentially realign, which may lower capacitance and losses.
  • Others question the audibility of any changes resulting from this molecular movement, suggesting that external factors, such as physical disturbances, may overshadow any effects caused by voltage.
  • One participant mentions the triboelectric effect, noting that static electricity generated by rubbing materials together could contribute to changes in cable performance.
  • Another participant argues that electromigration is a significant issue in semiconductors but asserts that it has no observable effect in larger speaker cables, challenging the notion of molecular realignment.
  • Concerns are raised about the psychological aspect of perceived improvements in sound quality over time, suggesting that listeners may become accustomed to the sound rather than experiencing actual changes in the cable's performance.
  • A reference is made to an external source that claims the idea of cable break-in is a myth, stating that no scientific justification exists for the phenomenon.

Areas of Agreement / Disagreement

Participants express differing views on the validity of the burn-in phenomenon and the effects of voltage on molecular movement. There is no consensus on whether these effects are significant or audible.

Contextual Notes

Participants acknowledge limitations in their understanding of the physics involved, particularly regarding the definitions of terms like "stress" and the mechanisms of molecular movement in response to electric fields.

KingNothing
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I was involved in a hot debate about burning-in of audio cables. It's a line that many cable manufacturers have used for years and years, and they basically tell unsatisfied customers "You have to use the cables for over 200 hours before they become accustomed to playing the sound"...

Now, I was saying it's crap. But that's just some background, the real question here is all about physics. Someone else said:

Regarding cables, I know the following to be true.
Applying a voltage gradient/ electric field stresses parts of the dialectric and causes the molecules to move around. Contining to do this will cause them to align differently than the stresses they were set with during manufacture. (Much like cryo but for different reasons) The result of this action lowers the capacitance but mostly lowers the losses in the cable.
Does this constitute "Burn In"?
I suppose the real question is one of audibility. There is no question that a cable "changes" with the application of electric fields. So the real question is, can humans hear it.

Now, I don't know a ton about how voltages can move molecules. So what I'm asking is:

1) Is this even true? Can voltages 're-align' molecules? What exactly is 're-aligning'?

2) Originally I assumed that electrons were the only thing that really mattered in carrying a voltage...is this still true?

3) Even if this person is right, would it be wrong to assume that any movement caused by the electrons would be near completely insignificant compared to the movement caused by, say, a person bumping the cable and making it sway? It seems in my mind that even if the voltage does cause the molecules to move, that even a slight physical disturbance such as a hand or an air vent would completely un-do any sort of organization that occurred from the 'stress'. Are these invalid assumptions?

Also, what is a 'stress'?
 
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KingNothing said:
I was involved in a hot debate about burning-in of audio cables. It's a line that many cable manufacturers have used for years and years, and they basically tell unsatisfied customers "You have to use the cables for over 200 hours before they become accustomed to playing the sound"...
The manufacturer is probably correct in stating the performance would improve with use. Years ago I did some very minimum studies on the “triboelectric effect” in ECG cables. Basically triboelectric refers to static electricity produced by rubbing dissimilar materials together. The rubbing of the wires (copper, gold…) upon the insulation does produce measurable static fields that in turn generate small currents which I assume would be heard as a background hiss. I can only guess why a cable would improve with age, so I’ll leave it at that.

[edit]A possible reason for the cable to generate static fields is that the inductance of the stranded wires within the cable would cause movement (microscopic) and the rubbing effect even if the wire was securely attached to a supporting surface.

...
 
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So-called "electromigration" is a significant problem in semiconductors. The flow of electrons through very small metal wires inside integrated circuits can actually dislodge metal atoms and slowly erode the wire to the point where it breaks the circuit.

In a wire the size of a Monster cable for speaker wiring, electromigration has absolutely no observable effect. Neither does any sort of "realigning of molecules."

Basically, if the wire needed burning in, the company would burn it in for you, to avoid complaints. However, it doesn't. They tell this hocus-pocus to the initially unsatisfied customer. The customer, believing the company, listens to his music for quite a while, and slowly becomes accustomed to the sound. Chances are, after a few dozen hours, the customer will no longer even really be able to remember what his gripes were. The company succeeds in preventing another return.

Neither the ear nor the brain is sensitive enough to hear any sort of difference that speaker cabling could cause. Besides, if you're doing 80 mph beside a semi truck making 90 dB of road noise, do you really think your speaker cables matter?

- Warren
 
The link below provides more info re: speaker cables than I think anyone would want to know. The writer agrees with Chroot.

http://www.audioholics.com/techtips/audioprinciples/interconnects/truthcablesinterconnects.php

Rod Elliott:

“Beware! If there is any suggestion that the cable needs to be 'broken in' before you hear the difference, the salesperson is lying! At this point, you should immediately let them know that you know that they are lying, and leave the shop. Cable 'break-in' is a myth, and is perpetuated by those with something to hide - no-one has ever been able to show that there is any scientific justification to the claim, nor shown that the performance has changed in any way whatsoever. Cable break-in is real, and occurs between the ears of the listener - nowhere else (most certainly not in the cable).”

 

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