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View Full Version : building a box, had a few ?'s



truckstoy
11-11-2005, 12:40 PM
going to build a slopt ported box for a pair of jl audio 10w7's
got box info off of Beerman's box caculator, just wanted to know if these #'s are good for a "SQL" box for my w7's.
box is for a 04 4-runner i listen to all kinds of music, looking for loud, very clean bass.

3.5 cu^ft net volume
32 htz tuning freq.
4.25" port width
61.625 square inches port area
39.75" port lenth
40w x 16t x 23d external dimensions

should i go smaller 3 cu^ft ?
lower or higher tuning point

i've built boxes before, i just want to get this one right......

any help would be appreciated :)

mike

PowerNaudio
11-12-2005, 07:01 AM
assuming you are using 3/4" mdf board.

enclosure dimensions:
external dimensions= W:40" x H:16" x D:23"
internal dimensions = W:38.5" x H:14.5" x D:21.5" = 6.955cu ft internal volume

port dimensions:
port internal dimensions: H:14.5" x W:4.25" x L:40.39" port values used for calculating port tuning
port physical dimensions: H:14.5" x W:5" x L:39" = 1.636cu ft external volume " assuming your only adding one wall for the port and using 3 current wall of the enclosure" this value is use for port displacement inside the enclosure.


sub woofer displacement= .09cu ft x 2 subs = .18cu ft

not calculating bracing.


6.965cu ft enclosure internal volume
1.636cu ft port external dimensions that actually sit inside the enclosure.
.18cu ft total of both subwoofers displacement
-
-------------
5.149cu ft final volume of the enclosure
2.5745cu ft volume seen per sub.

a 5.149 enclosure with port internal dimensions: H:14.5" x W:4.25" x L:40.39"
will tune the box to, 26.18Hz F3:22.30Hz, freq cutoff:25Hz, with your peak being at
33.5Hz@1.636db.

no apparent port noise at 1000wrms.

that will be an SQ enclosure. since the freq response is pretty flat from 27Hz to 120Hz