Working on my new box thought I would get some adivice before I finish this time. I figured the box to be out of 3/4 at these speks it will be double layerd thou 49x24x27 15.77 gross, port aera 171.00, net 13.29 at 33.83 hz. the port is 9" high 19" wide 15" deep is this the propper tuning or am i screwing this up the sxx say 5.4 to 8 optimal i would like to keep the box this size or should i go with 15 i realy want 18 I am running sxx 12 now, thought it yould be easer than 2 more 12"s and another sundown. I realy could use some advice the last two made a good fire.