# Box for FI BTL 18



## camaroz2894

Not sure where to post this so feel free to move if needed 

i have a buddy that wants me to build a box for a 1 fi btl 18. he ordered the spl one even tho he wants to play music on it i told him he should send it back and get the right one but he said build the box so i am. so my question is what is the recommended box size port size and port length fot this sub. space is not a problem it will be in the back of a ex cab chevy truck the back seat has been taken out. thanks for all the help


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## eggyhustles

sent it back

the spl one is a one note wonder for burps only.


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## TREETOP

The BTL will play music, no worries. The BL or Q may have been a better option but just dealing with shipping a BTL back would convince me to keep it too. 

Fi recommends a pretty broad range for that sub, from 5 cubes to 10 cubes. Tuning will depend on your desired use and/or your car's peak frequency. I'd recommend somewhere between 14 and 16 square inches of port area per cubic foot of net internal enclosure volume, the length will obviously be determined by your desired tuning.


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## 60ndown

if your trying to make an spl sub do music well tune low, 

28, 30, 32 no higher.

if you tune higher, you will wonder why it cant get the low lows on many tracks.

something like this

http://img35.imageshack.us/i/5cubes32hz62sqin6hk.png/

from

http://www.caraudio.com/forum/enclosure-design-construction-help/137804-free-box-plans.html


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## camaroz2894

So that exact box will be best for this sub?


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## 60ndown

camaroz2894 said:


> So that exact box will be best for this sub?


not quite, its only 17 inches tall. and tuned to 32. your going to have to make that box a little taller and the port a little longer.

for a few $$$ 20 or 30? there are many people here with software that can design a really nice box for that sub.

not me tho.

big waste of time to build a box that sounds like ass. better to spend a few $$ and build a box you know is going to perform great.

science is our friend, subwoofers have ts parameters, ignore them at your peril.

Thiele/Small - Wikipedia, the free encyclopedia

try this guy, he designed a nice box for me recently

http://www.diymobileaudio.com/forum/members/benny.html


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## TREETOP

Head over to realmofexcursion.com and ask the same questions. There will be more people there with hands-on experience with that sub.


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## eggyhustles

You guys are forgetting one thing

The spl version is made just for burps


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## KAPONE.SS

If I was you I would send it back. The gap on the SPL version is really tight and you will get alot of coil rub and mechanical noise running it on music. I have My BTL in 7.5 ft3 tuned to 30hz with 120sqin's of port and it kills the lows. Tried alot of other combinations of box size a tuning and I like this one the best.


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## silentbass

send it back...i had full loaded btl, universal in abt 75cubes tuned to 32....did real well in my explorer all around


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