PDA

View Full Version : Need the equation for port displacement



KnOkIn It 420
12-11-2005, 12:14 PM
I just need the equation for a port displacement.

IamDeMan
12-11-2005, 12:34 PM
L x W x H (slot port)

pi * radius(squared) * height (tube port)

KnOkIn It 420
12-11-2005, 12:37 PM
No man for the port not the box

IamDeMan
12-11-2005, 12:51 PM
No man for the port not the box
It's the same. Volume of a port is it's displacement in a box

Hypotetical: (totally off the wall numbers not representing a good box)

Box internal 32 X 17 X 15 = 8160 Cu In

The port inside is 2.5 X 17 X 20 = 850 Cu In (the amount of space it takes up in the enclosure or AKA DISPLACEMENT)(include thickness of inner wall when coming up with W btw)

KnOkIn It 420
12-11-2005, 12:58 PM
I am talking about round ports,I am sorry I should mentioned that

DBfan187
12-11-2005, 12:58 PM
http://audioforum.termpro.com/ubb/ultimatebb.php?/ubb/get_topic/f/8/t/024019/p/1.html#000003

IamDeMan
12-11-2005, 01:23 PM
I am talking about round ports,I am sorry I should mentioned that
I gave you that answer too man.

From first post:

pi * radius(squared) * height (tube port)

swimfreak26
12-11-2005, 01:50 PM
If you want to get really accurate you should include the port wall too (i.e. on a round port, do the OUTER diameter in the calculation).

If you're using MDF walls it can add sufficient volume and you'll need to do a separate calculation for the wall displacement over the port displacement.