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

Mr.  geoffkait
You bett right.
On cryogenics or burn inI answered already.
Directionality: Audio is an AC. That means that every 1/2 wave is flowing in the opposite direction of the other 1/2.
Please be kind to explain, who is changing the cables  directionality so many times a second...?
All home apliance use AC (at yours 60HZ at mine 50Hz). What about them? The electricity STD defines which is the hot line and which is the return. Try to convince them about  directionality. 
It is amazing, what kind of crap sales guys are trying to pull with Audiophiles that have no understanding in electricity, but are deep into spending large on the beloved hobby.

cleeds1
You're right. I don't think that would make a difference though.

OP
I was and am serious. I have easy access to wire and really wanted your advice. I am in the car audio business and I have a good crimp tool and I can terminate. I plan to try your advice. Do you still think I need 0 guage minimum to see the effects?
Thank you

By the way, in the car audio world for speaker wire thicker is always better just harder to hide.

Solder bare wire to speakers bare wire to custom crossover and form a soldered wire hook for amp screw clamp terminal.  Any suggestions?

Mr. keppertup
It is not a good idea to solder a o AWG wire.
Try to use a cable shoe and crimp it.
I would not solder my equipment's bindig posts to wires...
use banana plugs.