View Full Version : Interesting Important question about port length on carstereo.com!!

03-16-2010, 09:20 PM
PORT Size Calculations and Formulas for WOOFER and Subwoofer BOXES (http://www.carstereo.com/help/Articles.cfm?id=31)

read the bold and then if you dont understand that keep reading.

on this site in the port length calculator, under the box that says enclosure volume would you put the total area of the box in which the port would be inside? or would you put the volume of the space your sub needs and then add the port on to that?

So lets say you have a 12x12x36 inch space to put a box.(ignore the wood thickness) you have 3 cubic feet. so would you put three feet into this Calculator with a 6x6 port tuned to lets say 34(random numbers) you get a 23.02in length for the port. So the total volume of the port is (23.02x6x6)in=.48 cubic feet. So the QUESTION is would you have to build this port on the outside of the box or would this port go on the inside of the box. If you put it in on the inside of the box your sub(s) would be getting 2.52 cubic feet.

I can try to explain better but over the phone is better.

03-16-2010, 09:33 PM
If understand the question. You want to enter the enclosure size not including sub displacement or port. Then add port. I used it on my current box and am impressed.

SSS 18734
03-16-2010, 09:44 PM
That calculator does not take the port volume into consideration. To get that desired tuning with the dimensions you entered, the port would have to be external.

03-16-2010, 11:44 PM
Put in the net ft^3 that you want the sub to see. The way I do it is this. I have AxBxC to work with...say, 5ft^3 gross for a single 15. That'll probably work fine since I can make it 3.5ft^3 net like I'm wanting it to be. So basically I put in 3.5 into the box volume, pick my frequency, and experiment with port sizes until I find something that'll take up the right amount of room to leave me with 3.5ft^3 after all displacements. Adding extra bracing or 45's can help if you need more space to be taken up.

03-16-2010, 11:46 PM
There's a box volume and solid object volume calc on that same site as well. Use the solid object calc to determine how much space your port is taking up.

03-17-2010, 01:31 AM
i F*cked up then

03-17-2010, 02:55 AM
i F*cked up then