box tuning

[dsmman]

im trying to find out what this box will be tuned at its

35" w,17" h,20 1/4" d 5.23 cu ft with a 9" deep port. port area is 82sq

[andym85]

if that 5.23cubes is internally, after all displacement, then its about 50-51hz...

[dsmman]

its 4.64 cu ft internally and thats not after displacement its 1" mdf and i want 2 dd 9512's i dont know how to do all the math

[andym85]

what is the height and width of your port?

[dsmman]

its a audio enhancers box i dont have one i has just looking at and it does not say the height and width it just says the port area is 82 sq and port depth is 9"

[andym85]

externally: 35*17*20.25= 12048.75/1728=6.97cubes

internally: 34*16*19.25= 10472/1728=6.06cube

port displacement: well since your internal height is 16", im gonna assume your port is 16". divide that into 82" and u get 5.125"...so your port opening is 16x5.125 (or 5 1/8"). after taking into account the thickness of the wood your port volume displacement=16*6.125*8=784/1728=.45cubes

sub displacement: im guess around .19cubes per sub for a total of .38cubes

total internal volume after displacement: 6.06-.45-.38=5.23cubes...which is exactly what u said in your first post...funny how that worked out, huh?

that puts your tuning at about 47hz...to high imo...

[dsmman]

ok thanks for the help i guess ill just stik to biulding my own box

[andym85]

go for it...i would make the box a tad bigger and with a bit more port area and longer also...if its for daily driving i would say tune it to like 32ish...give or take a few hz