I am afraid a different sub wouldn't help much other than it might feel louder for the same volume level, this was what I experienced moving up to the PB13 from the PB12. I would still try the sub in various locations to see if you can achieve the sound/feel you are looking for, the sub crawl is more for even/loud sound, you may find a spot that works better for your tastes.

Jason
M80 v2
VP160 v3
QS8 v2
PB13 Ultra
Denon 3808
Samsung 85" Q70