ported question
Thread Starter
50 Watt CAFz'r
Joined: Apr 2004
Posts: 456
ported question
I am slapping together a basic ported box for 2 drivers, and it specs 2" port per sub.
I do not have 2" port though. What calculation do I have to make inorder to use 1 x 4" port rather than 2 x 2" port?
I do not have 2" port though. What calculation do I have to make inorder to use 1 x 4" port rather than 2 x 2" port?
Guest
Posts: n/a
Well you take this formula:
Lv = (23562.5*Dv^2*Np/(Fb^2*Vb))-(k*Dv)
Dv = port diameter (cm)
Fb = tuning frequency (Hz)
Vb = net volume (litres)
Lv = length of each port (cm)
Np = number of ports
k = end correction (normally 0.732)
and solve for Dv.
Or if that sounds like it will really suck - drop the volume, 4" port diameter and tuning frequency in the calculator here: http://carelia.scp.fi/~c9700368/putki.htm and it will tell you the length needed.
Lv = (23562.5*Dv^2*Np/(Fb^2*Vb))-(k*Dv)
Dv = port diameter (cm)
Fb = tuning frequency (Hz)
Vb = net volume (litres)
Lv = length of each port (cm)
Np = number of ports
k = end correction (normally 0.732)
and solve for Dv.
Or if that sounds like it will really suck - drop the volume, 4" port diameter and tuning frequency in the calculator here: http://carelia.scp.fi/~c9700368/putki.htm and it will tell you the length needed.
Guest
Posts: n/a
Since some people like things to be simple, and I lost the calculator I created a while ago, I integrated the above formula (Thanks DUKK!!!) into a simple and easy to use Excel sheet. You can download it here.
Just fill in the blanks in the yellow cells and you get the answer. I changed the units to imperial so that people can 'relate' better.
Have fun!
http://thewrx.netfirms.com/dl/port.xls
Just fill in the blanks in the yellow cells and you get the answer. I changed the units to imperial so that people can 'relate' better.
Have fun!
http://thewrx.netfirms.com/dl/port.xls
