View Full Version : Port size

11-04-2011, 10:59 AM
I just designed my first box and I wanted to know if my port was big enough.
In the manual it says for a round port 3 inch of diameter would be enough.
That makes about 7 sq inch.
The port I made is a slot port, I've used WinISD to calculate it and it is 12x1 opening and 17.8 lenght.
If I look at the size I should be Ok but I just wanna be sure because it is a slot port.

The sub is a image dynamics id12 v3 d2

11-04-2011, 11:03 AM
12 square inches of port seems awfully small to me. If you can make the enclosure larger and widen that port an inch or two you'll be in good shape.

11-04-2011, 11:10 AM
Maybe I could make it 1.5 inch x 12 inch.
But if I need bigger than that I will probably be looking for a round port.
What do you think would be better?

11-04-2011, 01:57 PM
Shoot for 14sq in of port for every cubic ft of box volume for that woofer. Ex- 2 cu/ft box = 28sq in of port. Round ports are more efficient so they don't require as large of an opening as slot ports. With a 12in woofer, you should never go smaller than a 4in diameter if using a round port or you will have terrible port noise.

11-04-2011, 03:56 PM
Ok so I will try to make it 1,6x13 since the box is about 1.5 cu feet it should be ok.
Do you think 34hz is a good tuning for that sub.
I want it too be in the middle between sq and spl.