Thanks for explaining. I would think adding two subwoofers would allow the bookshelf speakers to play down lower.
I am sure that the Sim will need 2 subs well controlled yes and they will be great...
My speaker woofer has 2 more centimeter of diameter and a bigger box well damped over 80 pounds of concrete on platform and springs under and over them under the damping load...
This is why they sound great ...With room acoustic control...But it is not suitable for a living room... It is why the only luxury in audio for me is not the gear but a room...
I am glad to need no subs...
The less is the best....😁😊
My deepest respect to you....