Where can i get a box design, for 2.8 cu ft tuned to 28? I plan on building it myself.24 tune is a bit low for in-car use IMO. Mike and I had several email convos regarding a ported box for my RL-p 15 (wanted to go ported at the time). We came up with the ideal enclosure and tuning of 2.8 cu ft tuned to 28 hz. It gave a relatively flat response.