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View Full Version : Port length, 1.5 Cubes, 32Hz



Rc 415
07-03-2006, 06:32 PM
Ok, so I have the box built, its 1.5 cubic feet, and I need to tune it to 32 Hz, so I plugged the numbers into the calculator below, and I get right around 36". Is this 36" the length of each port or is it like the statement below? (I have three 3" Aeros)
http://www.psp-inc.com/psp-inc.com/public_html/..%5Ccgi-bin%5Cport_length_calculator.cgi

Its def. like i said before,this is the combined length for all 3 tubes.
I went through every formula i have bookmarked,and they all come out the same.
3 3in ports@roughly 12in long will give you 32hz tuning.
Can anyone verify this statement? I always thought diffrent.

bjfish11
07-03-2006, 06:34 PM
Length Per Port

bimma85
07-03-2006, 06:35 PM
if you enter 2 4" ports and it says 20" long....that means 20" long for each port...not 10" long each port.

Rc 415
07-03-2006, 06:35 PM
So each port needs to be 36 inches then?

bimma85
07-03-2006, 06:36 PM
So each port needs to be 36 inches then?
if that is what it said....yup

bjfish11
07-03-2006, 06:36 PM
So each port needs to be 36 inches then?
Yes

Rc 415
07-03-2006, 06:39 PM
Ok, thanks guys.

Rc 415
07-03-2006, 06:45 PM
My last question is, will I notice a big diffrence between having flared ports and non flared ports?

xluben
07-03-2006, 06:50 PM
you also have to take port displacement into consideration, since your box is already built.

so with 3, 3" dia, 36" long ports that's about 0.4 ft^3 of displacement, which put the box at 1.1 ft^3 and the tuning at 37Hz!

ruger
07-03-2006, 06:51 PM
i been wondering that also, is this right ?
3cu. box with 4, 4" flared tubes 13 in long would be 55hz

if i plugged up one port, the closest i get would be
1 port pluged around 47hz
2 ports pluged around 39hz
3 ports pluged around 28hz

basiclly trying to make 1 box for a 10" that i dont have to remake.
for comp. and dd. so is that right?

Rc 415
07-03-2006, 06:53 PM
you also have to take port displacement into consideration, since your box is already built.

so with 3, 3" dia, 36" long ports that's about 0.4 ft^3 of displacement, which put the box at 1.1 ft^3 and the tuning at 37Hz!
You dont have to worry man, I got that under control, the box currently is extremely close to 2 cubes.

Rc 415
07-03-2006, 06:54 PM
My last question is, will I notice a big diffrence between having flared ports and non flared ports?
Now...back to my question.

Decipha
07-03-2006, 06:56 PM
you won't hear as much port noise with a flared tip... thats about the only difference

bimma85
07-03-2006, 06:58 PM
you also have to take port displacement into consideration, since your box is already built.

so with 3, 3" dia, 36" long ports that's about 0.4 ft^3 of displacement, which put the box at 1.1 ft^3 and the tuning at 37Hz!
you positive? I was thinking the same thing, but jntar said they already figure the port displacement in the calc. Said he wasnt 100% sure, though.

Rc 415
07-03-2006, 07:33 PM
you won't hear as much port noise with a flared tip... thats about the only difference
How bad will the noise be in reality though?

Rc 415
07-03-2006, 08:35 PM
Any one have any experience?

96civ
07-03-2006, 09:42 PM
If I'm not mistaken... which you've probably already figured out but if you need 36" port length, you technically only need 1 port with x" diameter and 36" in length, but you need either a larger diameter or a larger number of ports in order to increase port area to accomodate the port length...

Rc 415
07-04-2006, 06:10 PM
^^