Subwoofer for Wilson Maxx2


my room is about 22x33 ft, my maxx2 are sitting about 11ft from the front wall, and 8,5 ft apart

i get very good image, width..depth..etc.., however not enough bass

i tried to locate the maxx closer to the front wall, from 4 ft..etc.., however at 11ft everything are better, but not enough bass

so i want to add 2 subwoofer ...wondering any Maxx2 users or full range speakers user are running subwoofer and able to give me some suggestion ?

i do not want to spend that much for Wilson Sub...
mgmmgm
i had Cello Palette SIV and MIV ..and sold them, as if i need a EQ again.. i like to try something different, i do sell a lot of cello at asia, and i always keep a pair of cello performance II..as it drive almost all speaker whatever i plug in without too much matching issue

at this moment, i am using a pass labs XP-20, Cello Performance II and Meridian 808.2

it is very fine to be a dealer and share here, i suppose most dealer enjoy this hobby too

thx for your advice
Sorry, I was on family vacation. I have used Tara Omega, and currently use Transparent Opus. Both are excellent, however the transparent are unparalleled in my (limited) experience. I have demoed a few others (Valhalla, Kubala) which had definite weaknesses. I would try the best transparent you can afford. I'm sure there are others who may have cheaper recommendations. Despite what has been written since my last post, I stick with the JL113 recommendation. The Alexandrias have even more woofers than the Maxx and they still benefit greatly from the subs (which have smaller woofers). Plus you can place then wherever you like to reinforce them, and they have room correction.
those opus...is...so expensive, this why i wonder.if i go for second tier Transparent..what may be a good altenative

thx