[E-A-G-L-E-S]

It is something of personal taste. The single crossover is all that many receivers have, it is the general point between mains and sub.
80Hz is too high for many as it lets in some 80+ signals and that is more of a midbass. Some like 80Hx to get the punch.
I set mine to 80Hz for music and 60Hz for movies.