Xxx Box Help

[darren700 10+ year member]

ok, im desining a box for a 12" XXX, my maximum dimensions are 14" x 33" x 19", the recomended box size is 2.1 cubic feet for the sub. i want to tune at 28hz. one thing im confused about is how to port it, i was orginally planning to slot port it, however it seems that the box would take up alot more room if i did that. what confuses me is how come if i were to use a 4" diameter tube as a port, it would only have to be 17.64" long, according to this: Port Size Calculation

why is it so much smaller when using a round port than a slotted port? is there any advantage to using each? help is much needed, as the gained trunk space would help alot if i could build a smaller box because of porting with a tube..

thanks

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[bimma85 5,000+ posts]

ok, im desining a box for a 12" XXX, my maximum dimensions are 14" x 33" x 19", the recomended box size is 2.1 cubic feet for the sub. i want to tune at 28hz. one thing im confused about is how to port it, i was orginally planning to slot port it, however it seems that the box would take up alot more room if i did that. what confuses me is how come if i were to use a 4" diameter tube as a port, it would only have to be 17.64" long, according to this: Port Size Calculation why is it so much smaller when using a round port than a slotted port? is there any advantage to using each? help is much needed, as the gained trunk space would help alot if i could build a smaller box because of porting with a tube..

thanks

the sloted port was prolly double the size therefore needing twice the length //content.invisioncic.com/y282845/emoticons/wink.gif.608e3ea05f1a9f98611af0861652f8fb.gif. If you did aeros, Id go with 2 4" ones.

 

[darren700 10+ year member]

why do you say use two ports? because it allows the air to flow more freely? if i were to use 2 4" aero ports, the required length would be 38.21", is that the length for each port? or a combination of the two? that would pose a problem as the maximum length you can order aero ports at is 17"... this seems pretty **** confusing...

 

[jd_man_90 10+ year member]

with the xxx you will need two 4" ports if not more because of the amount of air it will move. and that length is a combination of the two they would both be half that.

 

[darren700 10+ year member]

HMM, 3 aero ports would require 58.78" inches, or 19.6" for each port, however you cant buy aeroports that long... what should i do?

 

[darren700 10+ year member]

wat about 3 3" diameter aeroports? that works out to 10.84" each, would a total of 9" diameter port be enough? or would i notice port noise?