now that my new sub is figured out i thought i would add a second sub. this is my older sub its a 12inch valoydne ported. i talked to the guy at SVS and he said he would add this sub but he would set the low bass filter between 40-50. is this the same as low bass x over? would i set the phase to 0 like the other sub or set this one to 180? i figured i might as well use this sub until i can afford a matching one and i don't think there is much resale value in a old sub