I have one Rockford Fosgate 12" T0, model # T0D412, that I bought several months ago. I decided to just buy a pre fab ported box and there was always port noise at most lower frequencies. It has finally bugged me to the point where I'm building my own box. Any ideas or dimensions other than the one recommended in the manual? Since I only have one sub, I'd prefer a ported or 4th order bandpass type enclosure for the most bang for my buck.