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UCF52
03-31-2007, 02:17 PM
alright, im building a ported box for my JL 12 W6.V1. I am following the exact dimensions from my spec sheet - it calls for two 2.5"x13.6" aero ports. well, i cannot find any aero ports online that fit that measurement, so i was curious if i can use either 2" or 3" aero ports instead. if so, how i would go about calulating the new port dimensions. i have 17.75" of depth to work with. any help would be great!

skadude016
03-31-2007, 02:18 PM
jus use a single 4 inch and tune to like 32 round about

Skip01
03-31-2007, 02:24 PM
psp-inc.com

Got a calculator on it...go nuts

UCF52
03-31-2007, 03:02 PM
sweet! thanks guys for the quick response.

UCF52
03-31-2007, 03:47 PM
okay i just want to make sure this sounds about right. box volume is 2.0 ft^3 after sub displacement. PsP suggest to keep the port a port length away from the box sides so a 4" port is out, but the 3" will work just fine. i plugged my numbers into the calculator and it came out with a port length of 3"x8.11". i just want to make sure this sounds okay. btw only one port is being used.

UCF52
03-31-2007, 09:19 PM
bump - just need a yes or no

Calikid
03-31-2007, 09:21 PM
if that's what the calculator told u to do then YES

UCF52
03-31-2007, 09:43 PM
lol alright. thanks!

mazdakid
03-31-2007, 10:11 PM
a 3" port is not enough for a 2cuft box

UCF52
03-31-2007, 10:18 PM
why?? what would you recomend

mazdakid
03-31-2007, 10:55 PM
i would reccomend 2 4" ports or a slot port

Trixter
04-01-2007, 11:36 AM
the original recommendation was 2 2.5" ports...which would be 39.25sq". a single 3" is only 28.26sq"...but a single 4" is 50.24sq"...go with a single 4".

UCF52
04-01-2007, 11:39 AM
a 3" port is not enough for a 2cuft box

well the box is already under construction so a slot port is out. why is a single 3" port "not enough" for a 2.0 ft^3 box. i dont really know enough about ported enclosures so any help/explanation would be great.


i would reccomend 2 4" ports or a slot port

i would like to go with a single 4" port, but the PsP site says to keep the port a port distance away from all walls (and assume the woofer as well). does this really affect the performance output from the enclosure??

Trixter
04-01-2007, 12:09 PM
well the box is already under construction so a slot port is out. why is a single 3" port "not enough" for a 2.0 ft^3 box. i dont really know enough about ported enclosures so any help/explanation would be great.

you could get away with it...but the more port area you have the less chance there is for port noise caused by the turbulance. the reason i said to go with a single 4" is because it is a little larger then with the mfg. recommended.



i would like to go with a single 4" port, but the PsP site says to keep the port a port distance away from all walls (and assume the woofer as well). does this really affect the performance output from the enclosure??

this is the "best case" install. the reason for it is due to the flare. imagine the the flare doesn not end at the end of the port but rather continues on. the best case would be to have the "expanded cone" away form any surface as much as possible to allow for the best, "uninterupted" sound waves. they would get "interupted" from hitting the box wall or even the sub. the main thing to concentrate on is the back of the port. this distance is quite important. as for the walls....do the best you can.

mazdakid
04-01-2007, 01:02 PM
the original recommendation was 2 2.5" ports...which would be 39.25sq". a single 3" is only 28.26sq"...but a single 4" is 50.24sq"...go with a single 4".

a single 4" port is only 12.5" of area, i dunno where your getting all of your numbers from

Skip01
04-01-2007, 01:38 PM
a single 4" port is only 12.5" of area, i dunno where your getting all of your numbers from

x2


:suicide:

fwb_1234
04-01-2007, 04:46 PM
he did 4^2 pi
instead of 2squared x pi.
1 1.53" port has the same as 2 2.5" btw.

Trixter
04-01-2007, 07:09 PM
yep...my screww up...my b-day was yesterday so i'm not all w/ it today....don't listen to me...well, today anyways.

UCF52
04-01-2007, 08:09 PM
this is the "best case" install. the reason for it is due to the flare. imagine the the flare doesn not end at the end of the port but rather continues on. the best case would be to have the "expanded cone" away form any surface as much as possible to allow for the best, "uninterupted" sound waves. they would get "interupted" from hitting the box wall or even the sub. the main thing to concentrate on is the back of the port. this distance is quite important. as for the walls....do the best you can.

i can fit a single 4" port on my baffle. my baffle is only 12.5" x 18" and the sub is a 12. so the area to work with is pretty limited, which is why i wanted to stick with a single aero port.

on the PsP site i plugged in...

Volume of Box in Cubic Feet: 2.0 ft^3 (after sub displacement)
Tuning frequency: 32 hz
Port diameter: 4"
Number of Ports: 1

and it spit out 14.61" of flared port length.

my box is only 16" deep (internally). will this create an "interrupted" airwaves for me or will i be okay?

should i maybe go with 2) 2" ports - creating a shorter port length??

UCF52
04-01-2007, 10:04 PM
ttt

Skip01
04-01-2007, 11:23 PM
What about external ports....or slot port?

UCF52
04-02-2007, 01:29 AM
well the box is already under construction (actually everything is together except for the top) because i was just going to use the dimensions from the spec sheet, but i couldnt find an aero port that measured 2.5"x13.6" (as the spec sheet called for). so a slot port is out. and to be honest with you i have never heard of an external port.

i think my best bet is to go with a single 4"x14.61" aero port, whcih would give me a tune at 32hz. a lot of the responses i have gotten have been mixed so its hard to tell what i should do. if anybody can try and help me clarify the situation that would be great!

UCF52
04-02-2007, 01:21 PM
bump

Trixter
04-02-2007, 02:13 PM
i used 2 4" areos with my 15" brahma in a 4cu' and it was the best box i ever built for it. sounded awesome and pulled good numbers too. everyone said that there was not enough port area but numbers don't lie. if the box is already being built and you only have room for the one try it and see. you'll probably be happy with it.

UCF52
04-02-2007, 03:49 PM
yea thats what i think im gonna go with; a single 4" port at the length the PsP site tells me is appropriate for the tuning frequency i am looking for. thanks everybody for the help and insight!