This is what i typed to subfanatic (demensions are internal)
i didnt expect the box size to reduce this much but at my current demensions the boxes internal cf is 2.33217592 quite a drop from 3.80 cf my box may end up a smidge more than 2.33217592 after i nail it all down exact but this will be so much easier to build and take up so much less room so far my demensions are 6.5 high x 31 wide by 20 deep to fit all three chambers for my two 6.5 tangbands
ok here it is final results and i will not change it lol ....The box ends up being (3.58398958333 cf gross)
6.5 x 17.3750 (3/8) x 21=1.3725043402777 1.10 cf is the target 31.104 hz at 14.5 long .14 port volocity 6.5 x 9.0 x 21=.7109375 .55 cf is the target 43.295 hz at 14.5 long .10 port volocity 6.5 x 5.0313 (1/32) x 21=.39743776041666 .275 cf is the target 61.228 hz at 145 long .07 port volocity 1.925 cf net wolume
.04 displacement per 2 inch port at 14.5 long so .08 per front chamber (interior ports) .02 displacement per 2 inch port at 7.25 long in chamber 1 and .02 displacement per 2 inch port at 7.25 long in chamber 2 near side (interior ports) .02 displacement per 2 inch port at 7.25 long in chamber 2 far side and .02 displacement per 2 inch port at 7.25 long in chamber 3 near side (interior ports)
so .08 front ports plus .04 interior ports in chamber 1 (.12 cf) .08 front ports plus .04 for interior port near side and .04 far side in chamber 2 (.16 cf) .08 front ports plus .04 for interior port near side in chamber 3 (.12 cf)
i got 7 X 5 1/4 X 3 1/2 .074435763888 per sub .14887152777 for both
those are all measurements of three chambers with cubic ft. and individual tuned ports there is two total ports on the front of each chamber using 2 inch pvc 14.5 inches long each and two ports using 2 inch pvc 14.5 inches long each internally joining chamber 1 and 2 and then another two ports using 2 inch pvc 14.5 inches long joining chamber 2 and three