Speaker wire guage rating

12, 14, or 16 awg wire, for tower harness? is there any reason you would need anything else but 16 awg wire?
I know amps make a difference, but the normal tower speaker should do fine with 16awg?

any thoughts here......

Depends on the amp power. Divide your power rating in half, divide the result by 12 volts, the result is the average ampacity it will see.

16 gauge up to 100 watts per speaker, 14 gauge up to 300 watts per speaker, 12 guage over 300 watts. Most towers run fine with 14 gauge.
If you go over 10 amps go with 14 or larger.

Over 14 gauge is overkill on most systems.

I run 13 gauge (metric equiv.), I am pushing 400 watts X 2 on my tower.