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View Full Version : Enclosure port, need help



Rudy'
12-11-2007, 11:21 PM
need some expert to check my enclosure calculation, it will be for alpine type-r swr-1242d 12", tried many online calculator & winisd but get different result, my plan is to build 2 cu^3 tuned to 32hz

are this correct or need to adjust the port lenght
http://i169.photobucket.com/albums/u205/brunix_mk6/ice/sketch1.jpg

another option is to use this design
http://i169.photobucket.com/albums/u205/brunix_mk6/ice/plan2.jpg

can someone advised where to put slot port & what's the port size, tube port will be easy but i'm trying to avoid that, this's for my small hatchback car

BuckyBoy
12-11-2007, 11:58 PM
i have heard that alpine type-r's dont sound good in sealed enclosures, so stick with the ported.

for 2cuft enclosure you port area should be ~30 and the first one you posted is only 24
the box you posted was ~2cuft ~32hz like you wanted.

Try this...
change width to 32
height to 14
port width to 2.5
first port length to 10
second port length to 18
and you should be set

chinxtaboi
12-12-2007, 12:09 AM
whered you get those calculations? i wanna build a similar box.. but specs off a tad here and there.

BuckyBoy
12-12-2007, 12:12 AM
whered you get those calculations? i wanna build a similar box.. but specs off a tad here and there.

i use winisd for port calculations and the re calculator to help with box volume and dimensions

chinxtaboi
12-12-2007, 12:35 AM
say my area to work with is 31"w x 14"h x 13"deep... what would my port specs be? according to re
square port height: 12.5
square port width: 1.5
square port length1: 10.75
square port length2: 10

i dont see how they figure the box volume to be 2.098.. but when i calculate volume
31x14x13 / 1728 i get... 3.265 or internal volume 2.454. ??????

thanks

BuckyBoy
12-12-2007, 12:39 AM
the port takes away from your internal volume.
the volume is correct on re, but it doesnt take into account subwoofer displacement.

Rudy'
12-12-2007, 12:59 AM
i have heard that alpine type-r's dont sound good in sealed enclosures, so stick with the ported.

for 2cuft enclosure you port area should be ~30 and the first one you posted is only 24
the box you posted was ~2cuft ~32hz like you wanted.

Try this...
change width to 32
height to 14
port width to 2.5
first port length to 10
second port length to 18
and you should be set

thanks mate, will try that, btw, any idea how & where to insert slot port for the 2nd wedge box?

BuckyBoy
12-12-2007, 01:02 AM
thanks mate, will try that, btw, any idea how & where to insert slot port for the 2nd wedge box?
idk anything about slot ports in wedge boxes.

bjfish11
12-12-2007, 06:57 AM
the port takes away from your internal volume.
the volume is correct on re, but it doesnt take into account subwoofer displacement.

From what a lot of people say, that re calculator is junk.

Rudy'
12-12-2007, 10:15 AM
so this one will be correct? gross= 2.758 cuft, net= 2.044 cuft, port displacement= 0.714 cuft & how to calculate port square inch?

http://i169.photobucket.com/albums/u205/brunix_mk6/ice/sketch11.jpg