Single or multiple strand wire and other cable design properties: what is their value contribution and does it matter for what?

[John57]

Recently I’ve become aware of a number of different designs for various cables

Speaker cable - my current best practice example is a 9ga multi strand twisted silver and copper thread made up of fine single threads. Others I use vary from isolated Westinghouse copper wire again in twisted geometry. Cheapest are silver tinned copper OFC 12ga

Interconnects- mainly 12 or 10ga typically copper

Jumper cables of solid core wire silver coated copper

Power cables I’ve never seen inside but vary in thickness and treatments

HDMI/USB typically proprietary brands wrapped in a number of layers of shielding

My question is around the science for these choices. On the one hand there is serious proprietary know-how involved. Oth there is scant knowledge of the principles of science including materials science, and many other areas beyond the superficial capacitance and inductance principles that are common boundaries of engineers and other writers.
The design approaches vary widely.
I’m less interested in which one is better and much more interested in discussing the principles and their (alleged) value to the work cables do in transmitting signal and inevitably noise (as unwanted signal).

 

[Speedskater]

There is not much understanding involved. It's mostly audiophile myths and mis-understandings.

And yes there are 'good engineering practices' for designing any type of cable and each cable type has it's own practices.

What type of cable are you most interested in.

 

[John57]

There is not much understanding involved. It's mostly audiophile myths and mis-understandings.

And yes there are 'good engineering practices' for designing any type of cable and each cable type has it's own practices.

What type of cable are you most interested in.

I find most cable design is focused on traditional capacitance and inductance properties and ignores local noise absorption from EMI RFI. Recently I was reading about Cardas interconnect cable design, their high end cables. They have adopted a shielding solution in their most expensive cable model.

There seems to be few agreed principles. For example, that shielding must be virtually water tight to be effective. Another grey area is grounding, with many different solutions available to a rather unclear problem.

 

[Speedskater]

When you write cable design, do you mean?

• Unbalanced analog audio RCA interconnect
• Balanced analog audio XLR interconnect
• Unbalanced digital RCA interconnect
• Balanced digital XLR interconnect
• Loudspeaker cable
• AC power cord

The needs of each are different and the best design standards for each have been known for decades.

 

[Folsom]

How do you know the RF is undesirable? CH balanced cables are unshielded specifically to allow it in, because people like it.

 

[microstrip]

How do you know the RF is undesirable? CH balanced cables are unshielded specifically to allow it in, because people like it.

It is known that some power tweaks include RF noise generators.