I did exactly what you did bro... I had 2 12'' type R's in a custom box built by vitveet... they hit hard but i got over it so i ordered a Fully Loaded BL 18 and bought a design off of vitveet again. I literally just got my 18 in and finished my box a couple days before.. The 18 sounds a shit ton better and is louder by far... totally worth it imo if you can fit the box i would do it... Looks sexy to