To sub or not to sub, that is the question.

[GMichael]

Famous last words.
ENGINEERS are always doing stupid things. WHY set your mains
(or any other speaker) to limit the bass they emit? In most ht
setups you need all the bass you can get. This is like the "turbo"
switch on old computers. ALWAYS set all speakers to as
large a setting as you can get.

Untrue. Some mains can be harder to drive than others. Driving those with an entry level receiver can be tough. Setting the speakers to small and letting the sub handle anything below 80Hz can free up the amp's load and give it more headroom.