You want the acoustic response of your sub-woofer and main speakers to sum flat.
If your main speakers have an F3 at 40Hz or below you'll get closer to that if you add a 2nd order line-level highpass with poles at 80Hz, Q=.707.
If they're sealed stand mounted monitors you're probably close already.
If your main speakers have an F3 at 40Hz or below you'll get closer to that if you add a 2nd order line-level highpass with poles at 80Hz, Q=.707.
If they're sealed stand mounted monitors you're probably close already.