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
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So how come whatever wire you use can make a big difference to SQ.
Because, as I've said elsewhere, there's no such thing as "perfect" wire.  Just trade-offs. More inductance in exchange for lower resistance and capacitance.  Less inductance in exchange for more capacitance.  

Even the insanely expensive stuff still trades one problem for another.  How big the problem is and how much it affects your system is what will make one cable sound better than the other.   

But it also means, depending on the application, that a $25K cable will be outperformed by a $20 one. 
Oxygen free copper is nice to reduce corrosion, but never mind OFC or OCCC failing in blind tests, or silver

Silver is a mind-blower for me.  Because silver creates its own set of problems in terms of signal conductivity.  Sometimes I wonder if there's just an opulence aspect going on there.  Like, if a manufacturer thought they could make it cost-effective (for them, not for you), they'd put out a 14k gold wire, just to see if it'd sell.  

In fact, I seem to recall back in the 80's reading a Stereo Review article about gold speaker wire.  But I couldn't say for sure who did it or what purity level it was.  

We end up where we started R, L, C.
And now comes the money question.

Presuming that I shelve the amps a few inches above the speakers (already bought shelf kits to do this), now I still have my 12-inch speaker cable run, BUT, I still have 2.5 meters between the amps and the pre.

So now I have a milliwatt signal being broadcast on a longer run than the high-watt signal between the amp and the speaker.

It seems to me that C should be my biggest concern when I contemplate my interconnect choices due to the longer run, though RCA cables tend to be far less transparent regarding their specs than basic speaker cable.

Your advice would be useful here.