Impedance curves for conductors

I haven’t managed to find measured impedance curves for different metals. I don’t see what else would precisely quantify the audible differences between metals used as conductors - for example silver is perceived as generally “brighter” than other metals so it seems obvious that silver’s impedance curve drops more rapidly as frequency increases than, say, gold’s.
Of course the matter is very complex and includes metallurgic factors at the lattice level, conductor geometry, the lot of it, but I’m just interested in seeing some measured results that correspond to the general characteristics of different conductors in audio systems.

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impedance of a cable is very dependent on the geometry, not just the metals involved :slight_smile:

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And of course the frequency and current of the signal as well as environmental factors. My guess is @rower30 has papers on just these parameters.

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When you change metals, you adjust for the skin depth and resistivity values. Aluminum is actually pretty darn good or audio if it didn’t work harden at the sizes necessary for reliability.

Many speaker voice coils are aluminum to lower the overall mass effectively as the wire is FIXED in place and can’t work harden, for instance.

More and smaller wires with a HIGHER DCR will improve the sound. Stick more in parallel to equal other metals DCR. When we get the aluminum DCR in spec (make them strands bigger) compared to the copper wire it is still too brittle.

It’s all a balance on the resistivity and skin depth. Copper is far and away the easiest to work with at decent value points. Silver and gold are good, too, but expensive.

Cable impedance is a simple phrase; physicals equals electricals.

Change the materials, DISTANCE and/or dielectrics and the impedance curve will change.

Best,
Galen Gareis

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If we want to define impedance (not resistance) characteristics for pure elemental metals at given temperatures,… why don’t we have such charts, actually?
Having a perfect monocrystalline conductive sample of an element isn’t that hard to have and to measure electrically. Of course the measurements should be standardized so that we have the same conductor structure for each being measured, etc.

rower, do you know to tell about some specific alloys that have beneficial properties over some elemental metals as conductors (used in audio)?
I know that brass is used for platings commonly and isn’t actually bad at all if it’s of proper metallurgic quality.

Here is where I can’t over step what I know from calculation and measurements…HOW a metal sounds, not just measures.

This is why we offer several choices in ICONOCLAST as we do have a preference for what we consider “beneficial”.

I do have a tech paper on materials if you want it. Kind of dry as it is just numbers and materials.

Best,
Galen Gareis

It isn’t sensible to attempt to correlate the electrical characteristics of a bare conductor in isolation to SQ because using bare conductors in an audio system isn’t practical. While it might be possible in principle, nobody I know uses bare conductors as interconnects, speaker cables or in digital applications. It is like attempting to correlate how a car would handle when the only part of it to be characterized is the engine without consideration of the body, suspension, tires, etc. IMO the question only makes sense when combined with the insulation materials and geometry being considered for a cable design. I’m going to go further by stating at audio frequencies (RF is a different ballgame but home audio is nowhere close to operating in RF) geometry and insulation materials are more important than conductor type for the overall complex impedance and group propagation in a cable. When I do skin depth calculations for the 20-20khz range I simply can’t convince myself silver is anything other than bling factor to justify higher prices. I don’t find in practice that silver is ‘brighter’ than copper all other factors being constant.

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I seem to remember Paul saying the material used for the sleeving causes chemical interactions effecting sound quality of cables as well