>>Though it's possible that a given manufacturer may mistakenly wire the terminals incorrectly, It is common practice that "red is positive and black is negative."

I guess the question is "what does positive mean in the context of a speaker ?". Cones go out ? Cones go in ?

M60ti, VP180, QS8, M2ti, EP500, PC-Plus 20-39
M5HP, M40ti, Sierra-1
LFR1100 active, ADA1500-4 and -8