Hi guys, I have not long been the owner of a fantastic new subwoofer; an SVS PB2 Plus. It really is a great piece of kit, it measures nearly as flat as my EQ'd REL Strata III even without EQ! and of course its incredibly powerfull and goes down very low, 20hz@115db! with no distortion. Any way I will stop ranting and get to the question. What effect does it have changing my sub type between normal and THX Ultra2?, apart from being able to change the crossover point between 125hz and 80hz and being able to use boundary gain reinforcement. I dont intend to use THX "BGR" so what are the other advantages if any of setting the option to THX Ultra2? Does it feed the sub lower frequencies than if its set to normal?