A cable question, sort of...

Thank you Al.  If we connect speaker with two separate wires apart the inductance of such connection would be proportional to area in between wires.  Bringing wires very close would make this area (and inductance) close to zero.  Twisting speaker wires (it would be stupid not to) reduces inductance even further reducing magnetic flux, that wires produce, to practically zero.  That's why twisting wires not only reduces electromagnetic radiation but also electromagnetic pickup (also capacitive pickup).  Coiling such two wires, even when not twisted creates bifilar coil - a type of common mode choke.  It doesn't matter if it is an air coil or it is on the ferrite core.  Mutual inductance is as high as it gets since two coils (wire and return) are interleaved.

https://www.wikiwand.com/en/Bifilar_coil

I’m probably guilty of trying to reason with people, who don’t want to learn having their mind set on proving that what they know is right. I would advise such, relatively new on our forum, people, that it pays to listen what Almarg says. When you argue with him on technical subjects (I wouldn’t) better check first if you have his education and experience.

When you argue with him on technical subjects (I wouldn’t) better check first if you have his education and experience.

OK, what level of education does he have that nobody should argue with him?

AFAIK Masters in EE in prestigious Columbia University.  What about you?