Revel M20 Woofer

No, the crossover was designed for that driver. You can't just drop in one that is "close".

in the not-that-distant-past Dynaudio charged me $300 for a TWELVE-INCH woofer, so for the Revel speakers, that seems to be unreasonably high. i'm no speaker designer but there should be a practical solution to this problem. but at the same time, a 1st-rate driver might cost more than $100.

You might check with Speakerex, they may have the exact driver you need for less dough.

Good luck,
Dan