Running six in my room, but my baffle wall mounted LCR's also have 18's in them. All subs are sealed subs.8CF with 18" REXXX4CF with 18" Malstrom-XTwo 4CF with 18" HT18D2'sTwo 2CF with 12" TC Sounds drivers.The SI 18's are also mounted in my baffle wall. So that gives me five 18's up front.
And your room isn't that large if I recall.
I currently have five, although two are stacked and bridged and are treated as one...so I guess 4 . They are SVS-PC Ultra, HSU VTF-15H MK2, SVS SB-3000, and stacked JL Audio Dominion D110s. Yesterday I just received dual JL Audio F110s (ver.2) for review as well. Kinda wish they were the F112s
Those are expensive little beasts.
I always want to add more myself, I currently have 2 Klipsch R-12SW subs. My room isnt the largest so they offer plenty of bass. Still wouldnt mind a couple more though.
Only two JL F113's.