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View Full Version : Effective port lenght=tuned at?



SQBubble
05-07-2006, 06:16 PM
17.5in of effective port lenght, how do u know whats it tuned at?

Beat_Dominator
05-07-2006, 06:18 PM
Need to know the cross-sectional area of the port AND volume of the box.

SQBubble
05-07-2006, 06:21 PM
Need to know the cross-sectional area of the port AND volume of the box.

wuts cross-sectional aera?

external dimension

width: 27in
height: 17in
depth: 18in
GROSS cubic feet: 4.78

internal dimension and specs

woofer disp.: 0.2
NET cubic feet: 3.10-.2 = 2.9
port size: 62square inch (15.5 x 4)

SQBubble
05-07-2006, 06:27 PM
its kinda like this

pwnt by pat
05-07-2006, 06:29 PM
get the plans then build the box?

SQBubble
05-07-2006, 06:30 PM
its already built..i just wanna know exactly wut its tuned @

keifersracing
05-07-2006, 06:36 PM
if the port is 17.5 in long you are looking at 41.02hz

SQBubble
05-07-2006, 06:41 PM
woww, i just did the calculation, it turned out 49hz, is it correct? I used JL's web site's calculation.

http://mobile.jlaudio.com/support_pages.php?page_id=165

and cross-sectional is the port size right?

keifersracing
05-07-2006, 06:43 PM
i have bass box pro 6

SQBubble
05-07-2006, 06:46 PM
where could I get this?

PV Audio
05-07-2006, 06:46 PM
You have port width, and port height. Post each, and multiply the numbers. That's the cross-sectional area.

keifersracing
05-07-2006, 06:48 PM
buy it or get it off of some one and it is not cheap

SQBubble
05-07-2006, 06:51 PM
You have port width, and port height. Post each, and multiply the numbers. That's the cross-sectional area.

ya then its 62sq.in(15.5x4), so I guess my calculation were good, but can someone just verify it?

keifersracing
05-07-2006, 06:56 PM
from what i came up with is 41 hz the box is 17hX27wX18d at 62sqin of port at 17.5 long

SQBubble
05-07-2006, 07:01 PM
from what i came up with is 41 hz the box is 17hX27wX18d at 62sqin of port at 17.5 long

but this is external box size! dont you need the internal NET box size which is 21x16.5x15.5, can u calculate with these numbers just to see the difference plz!

keifersracing
05-07-2006, 07:06 PM
how long is the port

SQBubble
05-07-2006, 07:18 PM
17.5in

keifersracing
05-07-2006, 07:21 PM
if the internal is 16.5 how can it be 17.5 it is 21x16.5x15.5 right iternal

SQBubble
05-07-2006, 07:26 PM
its kinda like this

its 17.5 of effective port length...correct me if im wrong though

SQBubble
05-07-2006, 07:27 PM
check post#4 for picture the red thing is 17.5

keifersracing
05-07-2006, 07:29 PM
i come up with 53.12

keifersracing
05-07-2006, 07:30 PM
i did not see that it had a back to it told port is 17.5

pwnt by pat
05-07-2006, 08:26 PM
Are any of you guys calculating in wood thickness for the port?

SQBubble
05-07-2006, 08:50 PM
wut do u mean?