Maggies with a subwoofer system - optimization?

I do not have a preamp input on the back of my Krell S550i, so a high pass filter will not work with my existing setup. I am just trying to tweak my system to another level. I mainly play Jazz but occasionally I push the system with Blues (Bonamassa)

i know my panels only go down to about 45 hertz - I have been integrating the Swarm into the system for a couple of months and it sounds great with the Maggies - actually listening at lower volume levels out of the Krell as the sub system is filling the bottom end effortlessly. My imaging on stand up bass and Hammond B3 organ passages has become amazing (Nora Jones - Till We Meet Again is blowing me away).

Thanks for the input.

Everyone - thank you all for the input on my quest to keep tweaking my Maggies and my new Sub system from Duke.

i have reviewed the multiple YT recommendations and I agree that I may make more gains in my sound looking at better speaker isolation and room treatments - I am going to abandon the idea of limiting the low frequency (under 150 hertz) going into my Maggie 1.6qrs. I feel ‘as is’ that the system sound has integrated very well -  I guess my reason for concern started when I saw some minor delam of my copper wire ( 4 spots near the buttons on the panels about 1.5 in in length) on the back of my 1.6qrs and considering their age (18 years old).

I am very happy with my sound after the addition of The Swarm. 

Again - thanks for the education.

tom8999