I have 2 25-31 SVS CS+'s with a sampson 1000 watt amp, but I need more bass. Don't get me wrong the earth shakes under my feet. How much of a difference are we talking about if I went to any of the following. 2 PB12 ultra/2's 2 PB12 Plus/2 I'm leaning more toward the PB12 Plus/2's because it seems more cost friendly. I need a double in bass. I was thinking of 4 25-31's but the wife would kill me. Oh and forget about an infinate baffle DIY. I already did this at a friends house with 16 Tempests. Don't have the time or room for it.