Horn Designs for brand X drivers


I am extremely interested in building some kind of front loaded horn boxes (3 of them) to increase the effieciency of my home subwoofer settup. I use 3 18" dual voice coil car subs driven with a 1400 watt amp. My spl levels are in the 120 range room loaded at 25 to 30 hz, and was told a flh would increase those numbers significantly. Specs on the drivers are as follows. spl 1w/1m-89.1, displacement-6513.3 cc's(397.4 cubic inches), mounting depth 8 1/4", revc-7.32, vc inductance,mh- 7.499, sd,sqM- .1159, bl-26.83, vas-423.17 liters (or 14.94 cubic feet), Mms,gms-372.63, fs-17.5, qms-11.942, qes-.417, qts-.403, Pmax-1000, and Xmax-14 mm. I have tried to download some horn modeling programs, and do not know what im doing, so can some one please help me design some horns that would give response down to around 20 hz with these drivers? Size is not a problem, nor is the construction of the enclosures. I have asked everyone it seems for help on designing my own "earthquake" style sub enclosures, and no one has helped anywhere else, just told me to do worksheets on different programs. I can't seem to understand all that stuff when I do get a download properly, so please help me. Thanks a lot for any and all help provided.


Follow Ups: