15" bl box port too small

[rain377 10+ year member]

i built a box for a 15" bl but like an idiot forgot about port area and i only have about 29 sq in. i'm building a new box today how do these specs look correct any if wrong. 20" wide 25" tall 25" deep port is 3.5 tall 18.5 wide about 37" long . box is 4.2 cuft tuned to 30 hz. speaker up port across the bottom facing back. looks like about 64 sqin of port.

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[rain377 10+ year member]

someone help me out with the math i'm not that great at box design.

 

[themommyvan 10+ year member]

Why not just make the port all the way across the bottom?

 

[rain377 10+ year member]

thats what i'm doing. box is 20" wide so with 3/4" wood port would be 18.5 wide.

 

[themommyvan 10+ year member]

My bad looked at it wrong

 

[rain377 10+ year member]

does that look like it will work though. dimensions, cuft, port area? i'll be buying the wood i a few hours maybe i'll post a biuld log.

 

[themommyvan 10+ year member]

I used the RE calc and came up with something different. 34 port length and 4.6 before sub displacement. Tuned to 30.5

 

[profundus-sanus 10+ year member]

that doesn't come out right..

comes out to about 3.6 net tuned to 35hz

 

[rain377 10+ year member]

so sould someone throw me a design that will work. i can go 20" wide because i want to eventually add a second sub and i have 40" wide to work with. i want about a 30 hz tunning and i can go about as high and deep as i need.

 

[profundus-sanus 10+ year member]

you trying to make it so you can just build an identical box for another 15 to put in next to it?

 

[themommyvan 10+ year member]

http://reaudio.com/speaker_box/LPort_Box_Calc.html

 

[rain377 10+ year member]

yeah basically

 

[rain377 10+ year member]

i've done the re calculator the only thing with that though is i have to make the height the width because port will be across the bottom not the side.

 

[profundus-sanus 10+ year member]

well, do you have any desired height?

 

[themommyvan 10+ year member]

yea Ive done that with my last box. It was for 4 18s