As per the last post, active sub woofers are much more tunable to work in a room than a lone pair of X2 where you can not easily control room boundary and tune out bass nulls.
If you want to get amazing sound but for mucho less denaro find a pair of Dali Megalines. My friend Clemment Perry of Stereotimes uses them with dual subs in a small room and they sound incredible. Clemment also uses a Tact for room correction.
If you have your heart set on the X2 consider a Tact and you might be able to tune the system to work with this size room.
I do believe in the comments made by the gentleman that sold his Maxxs, but even in a small room anything is possible if you work hard enough on it.