I know the X3 very well they are very good but limited on low bass ,in room maybe a clean 38 hz , I can see using 4.5 inch drivers for mids but midBass low bass at least at minimum 6.5 inch driver to truly pressurize a room, the mass of the bass driver does matter.a grand piano can go downto 28 HZ for example .
I was considering the x3 ,I would keep my SVS 4000SB subs from low 40s on down , the Bass is tight and good but lacks the impact that my subs can do .they are very tuneful though. that’s my only reservation with them , the X1 for sure a pair of Quality subs required.
then you have a very good set up ,the X2 are a smaller X3 and might be ideal for a medium room with subs. Having owned a Audio store for a decade I am useD to having the impact of a live performance ,and I have room treatments throughout the listening area. They are a very good value for the monies.