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

Thank you Mr. khiak

To rest my case, all who listened to me on this thread and followed, ended up happy and with way better sound than they started with (whatever was the old cable).

Could you please be kind to share some of your impressions on the sound with your new DIY cables vs. the old once (what were they?). Thanks.

I was surprised how strong the cable industry was represented here by some very annoying posts, or by others who bought their urban myths and tried to spread them. Both are so wrong! As they try to keep you in the dark and sale their cables (bad for you and too expensive).

Where is your dignity?

For my thread, it was silent for quite a while. I thought that no one will join the DIY any more. Mr. khiak proved me wrong (I'm happy he did). There is still a guy called mitch2 who said he is doing a DIY attempts but I think he was not really doing it.

Update of the excel table of the DIY cables:
https://imgur.com/a/utMuqzK
Mr. khiak, could you please be kind to add the missing data? Thanks.

I'm happy for all those who followed and ended up with a better cable, way better sound and little investment.
I am standing behind my word, that the calculated cable is the best you can have for your equipment. All others would do only a partial job and provide a partial sound quality of your equipment full potential.

b4icu,
we are thinking of changing from 4 AWG to 2 AWG to squeeze a little bit more from the amps. What is your opinion?
We are looking for better connectors from Furutech. Most connectors max wire 6 mm only 😰

" we are thinking of changing from 4 AWG to 2 AWG to squeeze a little bit more from the amps."

- But wait, isn’t the "correct" cable size based in the magic formula that includes the speaker specs. & the amps DF? If you go to a different size, would that not violate the prime directive?
- Who is the we? Do they have the same amp & speakers that you have?

"What is your opinion?"

- How can an opinion matter? Remember the formula tells all ...

Mr. khiak
For your equipment, going from #4 to #2 won't do much of improvment.
As per the AWG table: https://www.powerstream.com/Wire_Size.htm
The chnge in resistance is not that much from  #4 to #2.
For the banana plugs, I recommend on this:
https://www.ebay.com/itm/8x-Nakamichi-24k-Gold-Plated-Audio-BFA-Banana-Speaker-Plug-Screw-Cable-Wire...
and a short #8 to connect between the #4 and the banana plug.

Please be kindly reminded for my requests. Thanks.