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billy18bm
05-13-2007, 10:12 AM
are my calculations correct?

also, this box if for two type r 12's jw how this will work since the reccomended volume is 3.4cuft?... jw thanks..
http://home.comcast.net/~tshot39/boxer.jpg

Immacomputer
05-13-2007, 10:27 AM
1) Net volume is AFTER port and sub displacement.
2) You have 20.375" of port length and you need 23.15" to get a tuning frequency of 36hz.
3) Port length extends 1/2 the port width from the end of the port if one side runs along the wall of the enclosure.
4) You can find the enclosure volume much easier than breaking the enclosure into sections manually.

http://i2.tinypic.com/6aqsh1j.png

From there, take the number they give and multiply that number by your height and then divide by 12. You can also see from the picture the actual port length (the solid line drawn down the center of the port).

billy18bm
05-13-2007, 10:46 AM
so i did wat u said heres a pic

on the port i went out 1.5" from the middle of my port?

http://home.comcast.net/~tshot39/huh.jpg

Immacomputer
05-13-2007, 10:48 AM
Those look like the same numbers I found. 3.01 cubic feet tuned to 38hz.

billy18bm
05-13-2007, 10:55 AM
how bout now
http://home.comcast.net/~tshot39/done.jpg

Immacomputer
05-13-2007, 10:57 AM
That looks to be right about on 3.0 cubic feet tuned to 36hz.

billy18bm
05-13-2007, 10:59 AM
thanks man i appreciate all the help

this box is for two type r's...12"...they reccomend 1.7 cuft a piece or 3.4 for 2 but i dont have the space should this work well.. jw if you know
thanks again

Immacomputer
05-13-2007, 11:00 AM
Well it should be pretty loud and pretty punchy but it will be heavily lacking in the 30hz range.

Blove1991
05-13-2007, 02:41 PM
Have you already bought the 12's? ...If not buy 10's and they will love that amount of space

billy18bm
05-13-2007, 03:00 PM
yes right now i have them sealed at around .9cuft... *****.....

NewToTheGrounds
05-13-2007, 05:20 PM
can u make the box bigger or are u limited?

PSturmer
05-13-2007, 08:12 PM
thats not enough space. do one ported in there.

billy18bm
05-13-2007, 08:43 PM
im sort of limited... how much space should i give them my original goal was 3.4cuft.. but i really cant do that w/o moding.... how much space do you guys reccomend.... and do u think i should tune differently..? maybe 30? jw i like the sound of a 30hz wave better than a 36 but idk if its becuase my car shakes more or wat??.. idk just need some advice thanks..

Blove1991
05-13-2007, 08:51 PM
No point in tuning it low in a small box.....I would do at least 4ft^3 at 30hz

billy18bm
05-13-2007, 09:14 PM
no space....... lol CAVALIER.....

billy18bm
05-13-2007, 09:14 PM
36 will sound decent? w/ that amount of space 3.0 cuft.. right?