No one actually knows how to lculate what speaker cable they need

@b4icu.  
I voice my cables by ear.  I use what some refer to as “tone” wire and change the gauge, construction and connectors based on what folks want sonically.  I am a custom builder.  I love the sound of Duelund stranded and tinned copper in oil impregnated cotton and use it often. 

I also perform modifications to speaker crossovers and tube gear.  I know what parts sound like based on my long experiece using them and match this knowledge with what the customer is looking for. Yes, I use my ears and known sonic differences between types and brands of wire, caps, resistors, inductors, rectifiers etc....

It is just me making cables out of a spare bedroom driven by a passion to help fellow Aphiles enjoy their systems more fully for reasonable money. Very small part time business that is gratifying.  

Mr. grannyring

Thanks.

I assume this method of "voice cables by ear" would apply when you sale a complete system, to include the amp and the speakers.

What if a customer comes in just for a speaker cable, and has a gear that you are not so familiar with its sound?

If I may summarize your method, it is mostly based on your intuition and some past experience that is based on your personal likes and dislikes. I have a little problem with that. You may know by now, that two people can listen to a system playing in an environment, and have different say about the very same sound. Wouldn’t you feel better if you would have a blue print or a formula in hand, that would specify by engineering methods what is the optimum cable that customer really needs?

What is the thickest cable you can offer a customer? How much that cable cost?

@b4icu 

Wouldn’t you feel better if you would have a blue print or a formula in hand, that would specify by engineering methods what is the optimum cable that customer really needs?

When you find one then by all means clue us in.  If everyone had the same opinion of how the “optimum” cable sounds then we would only need one cable manufacturer.