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Math + Logic + Science = something completely mad...

So, I've done a metric fuckton of research, notwithstanding the clear bias the man who designed and built my Belles has against esoteric cabling.  And here's the conclusion to which I arrived. 

My monoblocks are sitting on top of the speakers.  The distance from the amp to the speaker is barely a foot, which is exactly how long a run of wire I intend to use.  Goal is to minimize the effect the wire has on the sound.  

According to the calculations I've seen and done, the skin effect depth on copper wire at 20Khz is 461 micrometers.  Meaning a 19-gauge copper wire (911 mics diameter) would reduce skin effect to zero.  As in no impact whatsoever on the signal. 
 
Of course, it's actually very difficult to find 19-gauge wire.  18-gauge (1024 mics) is much easier, and the skin effect is near zero, but not quite zero.  Seems to be an acceptable compromise. Could go down to 20-gauge and eliminate skin effect entirely.  If I could find insulated aluminum wire, 18-gauge would eliminate skin effect entirely, because skin effect depth on aluminum at 20khz is 580 mics.  

12 inches of 18-gauge wire produces 0.006 ohms of additional resistance.  20-gauge = 0.01 ohms.  

Frankly, I don't see the value in spending big bucks on esoteric, heavy-gauge wire for this application.  I'd rather make the bigger investment in the 2m runs from the preamp to the blocks, because that's where the wire's going to have a hell of a lot more of an effect on the sound.  

Stepping back to allow you all the opportunity to punch holes in my thought process here. 
jerkface
dletch2
455 posts
 
So you're saying that the speaker vibrating the amp will cause microphonics in the tubes?

Yes


Only reason I bothered with the math on skin effect is because so many of these esoteric high-end cables do random weird stuff like adding dielectrics to "phase-correct" the signal.
 

They say a lot of things that are not true. That is why they never provide any useful information. If they provided useful information, no one would buy them.

jerkface OP
73 posts
 
Yes

Even when the amp has isolation feet on it and the speakers are sitting on a concrete floor, which is the ultimate vibration sink?  Asking in earnest, not to be argumentative.  


erik_squires
16,037 posts
 
While I believe that cables matter, skin effect is the biggest piece of hogwash ever.

A more likely explanation for cables sounding different, based on what I've heard, is that the amp and speakers are more sensitive to the miniscule LC and R values than the math would have us believe. Perhaps feedback also plays some role here, but 100% of every cable effect I've ever heard can be explained purely in the frequency domain. Oversensitivity to basic cable measurements could explain it.

Also, most cables are way pricier than the apparent changes they produce.
jerkface OP
73 posts
 
A more likely explanation for cables sounding different, based on what I've heard, is that the amp and speakers are more sensitive to the miniscule LC and R values than the math would have us believe

That's an explanation I can probably buy into a lot easier than idiotic jibberish like "time-correct windings".  

So now I'm thinking some basic 12-gauge Belden with some nicely welded spade ends from Blue Jean Cable is the correct answer here.  

One point was made in an article I read the other day that I had never contemplated, but certainly could appreciate, is that copper wire certainly does corrode over time, and some appreciable difference can be achieved just by replacing it with new periodically.  No matter what the new cable is, it'll sound better than the old one, because it's new, clean copper.  Fast forward a couple years and it's no longer new and no longer clean, and it'll need replacing again for optimal results. 

Which makes whatever miniscule gains that one could make spending $5K on a pair of one-meter runs kind of absurd, considering those gains will disappear over time from plain old, natural copper degradation. 

I can show you a photo of some Monster wire (that was given to me by the gentleman who sold me my Belle Klipsch) that is 10 years old and thoroughly green *inside the insulation*.  
russ69's avatar
russ69
3,496 posts
 
"...Even when the amp has isolation feet on it and the speakers are sitting on a concrete floor, which is the ultimate vibration sink?..."

The amp designer has done what they can do to reduce airborne microphonics (chassis resonances) but mechanical resonances from placing amp on vibrating surfaces will smear the sound sometimes and should be minimized as much as possible.     
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