Well I gave up bothering about sub size long ago I would have liked to try the FV15-HP but shipping to Canada ($350 !) coupled with warranty issues and duty/taxes made me choose another option -- especially since I was considering dual subs. Wasting $700 on shipping is not a very interesting proposition and there's no way I'd have hauled two FV15-HP from the border myself What crossover did you chose to go with that sub? It's sealed right? Are you using the standard 80 Hz with your RC-70s?