Hi, I was looking at buliding a new sub. Something sealed with a couple PR's to help keep the overall size small. Right now I have a SDX-15 sub and a ep-2500. I was looking at WinISD and was thinking of something around 3.5 to 4 ft3. As for the PR's I saw the 18" 2100g ones at CSS and the 15" 1400 grams and have no idea what to pick. I have never used PR's and dont know a whole lot about them. Im interested in what others have used. Thanks!!