Add JL Audio CR1 crossover and a pair of subs. I use a pair JL Audio F110 subs. It’s not about adding bass. It’s about controlling the bass and dialing it to the room. If you are in the Chicagoland area this store lets you try things in your home before you buy:
https://holmaudio.com/
Your gear is really good. Better than mine is right now. I think this can be solved with cables, isolation, and a subwoofer system. I hope this helped.