Congratulations on your upgrade. Obviously subwoofer room placement is key. Also keep in mind that after getting LF reinforcement from the sub this may allow your mains to be repositioned as well. Your mains my now need less room reinforcement to help the bass and having the flexibility to move the mains away from the walls can improve your imaging and sound stage. Have fun and cheers.
Adding JL Dominion d-108 sub… surprise
No fan of subs. My experience, they muddy rather than enrich. New found appreciation for at least one in one of my systems.
Modest casita system: iPod, Luxman dock, Naim Atom set upon Quadraspire SVT stand, Puritan Labs P106 conditioner, Patrick Cullen shotgun copper cables and PC, ATC 7 speakers on massed stands and…. sub. Really fills in the bass and seems not to muddy. Breathes oxygen into the dynamics overall.