# bass box pro design need little help.



## enerlevel (Jun 6, 2009)

amp:- soundstream 2000D
subs :- 2 splx 12" 

ok after all the parameters , and calculating the box size , i get the vent length of just 14.78". tuned to 35hz. 
question.
isnt 14.47" port too small for 2 12" splx? and wont it bring up port noise issues?


Pictures by enerlevel - Photobucket


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## cubdenno (Nov 10, 2007)

length of port for a specific frequency is determined by box volume and area of port.

Give me volume of enclosure and I will tell you port.


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## enerlevel (Jun 6, 2009)

the dimension of the box is 14x36x20 external


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## cubdenno (Nov 10, 2007)

Based on SS's specs for the woof, they want 3 ports 4" in dia. by 18 " long for 1 sub at 2 cu/ft.

you have 4.62 cu ft gross. before woofs, before ports

I would build a common chambered box and slot port it. i would tune it higher than 37. Like 45 hertz. What type of car?

In car you should hit in the upper 20's fine. 

make port 5inches wide X 12.5 inches high X 17 long. This will take up about 3/4 of a cube of internal volume along with woof displacement it will put you a bit lower than 45 but you should be fine. It should also be a fairly quiet port. Though there still may be a bit of huffing but it shouldn't be dramatic.

I use WinISD for the port tuning info.


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## enerlevel (Jun 6, 2009)

ok i tried making a box tuned to 35 hz.... it doesn sound very good. the high spl "ring your ears" effect went down and nor did the sub hit low very well.....


the other box tuned to 38hz sounded much better for spl effects.

so the final result i have is 
4.305 cubic foot gross without any sub displacement or port......

the vent size is 12.5 height and 3" wide.. now the only issue i have is the vent length.... its really funny cause with the same parameters , all different softwares show different lengths for the same tuning frequency...... i dont know which software is accurate..... 



p.s the car is civic sedan..... dont u think tuning to 45hz would really mess up rap songs>??


also i was thinking.... wat if i use pvc round 6" ports?? then i could at will change the frequency from 30 to 40hz.... depending on my mood..... is this a good or a bad idea?


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## cubdenno (Nov 10, 2007)

My son has 4 8" subs in an enclosure tuned to 45. he hits 141 at the dash. He listens to predominately rap music. It gets in the upper 20's fine. We run the subsonic at about 25-30 hertz.

How would using a 6" round port allow you to change the frequency at will?

Tuning involves internal volume of enclosure. Area of port and length.

It can be a math headache because every time you lengthen a port you decrease the box volume which is counterproductive to the lower tuning.

The 3" wide port will give you a lot of chuffing but if it is in your trunk, you should be fine.

WinISD gives me a length of about 7.5". this will give you close to 45.

Play with box placement in your car. Facing forward, backward, up... you get the idea.


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