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View Full Version : How to do Two ports for 1 chamber???



JayDolla513
05-31-2012, 12:17 AM
dont have much height to spare so how do u do the math to make one port into two?

brown7348
05-31-2012, 01:31 AM
Not really sure on that one, i rebuilt a prefab box the other day, it was a 2 12 box with port in the middle, i found it easy to just change the front plate an just put the port at one end of the box, sounded 10xx better than the fake ports they build..

kushy_dreams
05-31-2012, 02:05 AM
You divide the volume of the box by the number of ports.

for example: If you have 3 cu/ft and want to use 2 4inch ports, divide 3 by 2 to get 1.5 for volume then use that to calculate port length.

TaylorFade
05-31-2012, 06:26 AM
You divide the volume of the box by the number of ports.

for example: If you have 3 cu/ft and want to use 2 4inch ports, divide 3 by 2 to get 1.5 for volume then use that to calculate port length.

say wha?

Just split the port in two and keep the length the same. What's the problem?

i.e.- if you have 50sq in of port 20" long, just make (2) 25sq in ports 20" long.

disturbed471985
05-31-2012, 07:21 AM
say wha?

Just split the port in two and keep the length the same. What's the problem?

i.e.- if you have 50sq in of port 20" long, just make (2) 25sq in ports 20" long.

Taylor you gonna be in the Sport area anytime soon??? Id like to get some advice from you in person...

n8skow
05-31-2012, 11:53 AM
Kushy actually has the correct method.

OP didn't mention if this is a slot port or aeroport though.
The math is different, can't just divide in half and use same length.
More ports = more surface area = more friction in the port, which means the tuning will be different.


say wha?

Just split the port in two and keep the length the same. What's the problem?

i.e.- if you have 50sq in of port 20" long, just make (2) 25sq in ports 20" long.

TaylorFade
05-31-2012, 01:45 PM
Kushy actually has the correct method.

OP didn't mention if this is a slot port or aeroport though.
The math is different, can't just divide in half and use same length.
More ports = more surface area = more friction in the port, which means the tuning will be different.

I forgot you guys care about the difference between 31.64hz and 31.92hz.

---------- Post added at 11:45 AM ---------- Previous post was at 11:45 AM ----------


Taylor you gonna be in the Sport area anytime soon??? Id like to get some advice from you in person...

I actually might be. Lookin at another CRX up there. You can text me anytime though, man.

kushy_dreams
05-31-2012, 02:33 PM
say wha?

Just split the port in two and keep the length the same. What's the problem?

i.e.- if you have 50sq in of port 20" long, just make (2) 25sq in ports 20" long.

We both have it right

some wipe back to front, others front to back

n8skow
05-31-2012, 04:51 PM
...run the numbers for yourself
It's a more significant difference than you think.


I forgot you guys care about the difference between 31.64hz and 31.92hz.

Jroo
06-01-2012, 09:38 AM
You divide the volume of the box by the number of ports.

for example: If you have 3 cu/ft and want to use 2 4inch ports, divide 3 by 2 to get 1.5 for volume then use that to calculate port length.


Is this the correct math for slot ports?

n8skow
06-01-2012, 10:38 AM
slot 'and' aeros...