A cable question, sort of...

When you "coil" up the wire, you affectively create a parasitic inductor

No, you don't.  You're not coiling the wire.  You are coiling the cable  (big difference).  Look at the link at my previous post.

In addition increase in reactive impedance, even for the wire,  would be negligible (miliohms) at such low frequencies.

With other words; it doesn’t matter how I "roll up" the sub woofer cable?
Power cables in an eight, sub woofer cables any way that is suitable, likewise ordinary speaker cables?

I would just coil it neatly.  For power cables coiling is beneficial (as many turns as possible).

No, you don’t. You’re not coiling the wire. You are coiling the cable (big difference). Look at the link at my previous post.

It’s just the same. I said "wire" but I could have said "cable". When you coil up either a wire or cable (pick your language preference), you affectively create an inductor - pretty much basic electrical engineering 101 you learn first in school.  The link you posted doesn't say much if anything.

But like I said, if the cable is long enough, you probably see a difference. If the cable is short, then probably not much.

@andy2  there is a big difference between cable and a wire.  Coiled wire inductance is increased because magnetic flux created by each turn adds up.  Cable has two wires that create magnetic flux in opposite direction and coiling them would create something that is called "Common Mode Choke" - a choke that has inductance only for common mode signals and no inductance for normal mode (differential) signals.  This principal is also used in creation of wirewound resistors that have no inductance (bifilar windings).