A cable question, sort of...

When you "coil" up the wire, you affectively create a parasitic inductor.  If the cable is long enough that may end up to have too much inductance from the coiling affect, the parasitic inductance may create some resonance which in turn could make the bass of the subwoofer sound a bit mushy.  The question is if your cable is long enough that it will create enough inductance that it will make a difference in listening.  

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.