as for the caps,you need one per driver, and you need to go off the dcr of the driver. also the cap needs to be rated close to the voltage of the amps output. if you wat a decent "bass blocker" go to parts express and get you some goods caps..
Im aware MY mids arent supposed to play above 2500hz, they wont be.
And the st350's are 8ohm, so these are the only ones parts express has that semi fit the bill, if I bought 3 of those (1 spare) my tweets would only be seeing 2800kHz+
Closest bass stopper I can find on amazon (where Im buying everything) is