macisme

I would do 20-22 cubes total after all sub, bracing and port displacement and do 400 too 440 sq in of port I'm thinking I may have to redo my box again.... can you suggest any decent programs to help me figure all of this out?

How would I calculate the port size needed for doing a hair trick with 4 15" L7's? Right now the port looks pretty much like a hole in the side of the box lol.. it's 10 x 10 x .75 (the thickness of the wood) used a port calculator and it said that 10x10x .78 would be around 40 hertz. I wanted to drop it down to around 38 hertz and I kinda though the port was a bit small in size as well. I am pretty new to all of this but I am very interested in getting it all done the right way. Thanks for any help you can give me. Right now the 4 subs are on "4krms" with no knob and half gains. I plan on buying two 3500's in the future (which is why I am here ). Box is around 21 cubes. subs require 4-6 each. Max being 24. 21 was as close as I could get and be able to fit them in my SUV under the top of the back seats..