The numbers from the PB12-NSD test and the VTF15h test can not really be compared. If you want to see why, look at the numbers that Paul Apollonio and Josh Ricci came out with with the Rythmik FV15HP, the same exact unit and different results. From this I would say that Paul's measurements should only be used to compare with his own testing, and likewise with Josh's. Regardless, there is no doubt the VTF15h will have a lot more output. These subs aren't really in the same class, the VTF is more comparable with the PB12-Plus. The VTF2 or VTF3 is the PB12-NSD's proper competition.