I'll be setting up a new system in a second location soon so keen on hearing about others' sub integration. In regards to plugging ports in ported speakers as @erik_squires suggested, while this lowers the f3, doesn't it also lessen the effective roll-off slope at the low end? Wouldn't a steeper one be easier to transition to a sub like the SVS with selectable slopes? Also along these lines, what role does the hack of adding straws in the ports make? I thought this was supposed to de-tune the port's dominant tuning frequency while still allowing for the same mid woofer performance that the XO was designed for.
Since most subs interact with mains like stand mounts around 80hz, and the "phase correction" on subs really operates as a time delay based on 80 hz, a setting around 90 deg should help mitigate causing a notch or a bloom. All else being equal. Room etc.