I would not suggest putting all three in one enclosure, but rather each one in its own enclosure, placed properly in the room to balance the output. Then add an eq to balance the response, and it will outperform a more expensive "theater" sub woofer. In all reality, you could have ruler flat response from approximately 20hz-80hz at over 100db. You would just need a good eq.
The sub itself is pretty linear considering its age. Not nearly as nice as the new W6v2's or other new drivers but fairly decent.