Alright I just got my type r 12's sold today and I'm ready for my replacement! I'm pretty set on an Fi SSD, but I'm not sure on the size. It's going in an SUV so space isn't an issue. I'll be building my own box (ported) I really want the 18, but I'm worried it won't be responsive enough compared to the 15 since they will be on the same power. I know the 18 will be louder, but I feel like the 15 will give more punch and sound "tighter". Let me know what you think, I'll be ordering on Monday. It will be going on a Hifonics 1200D at 1 ohm.