what spl's you getting? the rew modeling for my space says I need the sub close to mlp, like closer the better, less than 6ft away...thats modeling software anyways. mine is 6 feet away and I get lots of tactile punch at 100-110db. it doesnt get much louder until I add backup subs, but I am in upgrade stage so jtr/rhythmik it will have another as I move older subs to smaller rooms in house.
Power: Marantz sr7008, NAD C 275Bee x 2, Video: Oppo 103, Samsung 75un6300
Speakers: Focal aria 948, Focal cc900, Klipsch synergy KSF 10.5 Subs: Rythmik FV25HP, Rythmik FV15HP