? best highpass point for pair of RB-81 II

what would be the best highpass point to use on my pair of Klipsch Reference Series RB-81 II Bookshelf Speakers
on my crown xls amp 45 , 47 , 50 , or 60 hz ?
which would be the best & smoothest role off point ?

i have my receiver’s xover for my fronts set at 70z an speakers set to large as im not using a sub
my receiver has hi & low slopes as part of a parametric per ch eq an a default output
vi xlr at 9vrms without eq an 4 with (eq is enabled) my crown xls is currently set for 1.4 sensitivity

an id prefer to add a bit of a bass bump by setting the eq’s low end like this
low shelf at 200hz at 1.5+db & the 50hz band at 1.5+db at with a Q of 1
i normally keep the 400hz band at -6db with a Q of 2 as the low to mid bass details an tones between 200hz - 600hz get muddy ther if i dont

150 and 200hz don’t seem like bass frequencies, but more a roaring guitar range.

80-90 Hz and down is what I would consider just bass. It’s a bit overwhelming all the frequency options, but I guess it’s not much different from a large range eq