Well the other day my sub got damaged wile having new carpet put in ( The tube got smashed by accident My own fault )so any how I will be building another one. My last sub was a sealed 16"by 42" don't know how many liters that is,with a Dayton 15"DVC. It sounded pretty good but this time around I would like to see if I can get just a little more out of it,I was thinking of trying a ported system. Dose anyone have any good suggestions for what I should go with, size is no big concern so I'm pretty open to anything.I'm thinking something around 20"diameter to make building a little easer this time,fitting a 15" sub in a 16" tube was kinda a pain last time. What I will be using is My current Dayton 15"DVC & PE 250 watt plate amp,Any suggestions on what route to go this time? Thanks for any help..