No problem. Cross all fronts to the sub at 80Hz to give the Onk less of a workout. Set the Onk to 8 Ohms and not 6.

Consider the 160OW though. There is nothing wrong with the 180 but the 160 is very good and less expensive.

Check refurb and B stock. You may find them there.

House of the Rising Sone
Out in the mid or far field
Dedicated mid-woofers are over-rated