View Full Version : Port tuning

01-27-2004, 10:22 AM
Ok so i pretty much know how to tune the box accept i dont know about port displacement.... Any info or tutorials on tuning a box would be great. I dont want to have to spend 10 bucs on a box design.

01-27-2004, 10:39 AM
download winisd, its a free program, that helps you design boxes, it will calculate everything for you
Just search it


01-27-2004, 10:39 AM

01-27-2004, 10:54 AM
yea i use win isd but does it subtract the port displacement already?

01-27-2004, 11:04 AM
winisd does not figure port displacement. You have to figure that out on your own. The box size You input must have port disp., and speaker displ. already figured. Hey, its a free program, you cant expect everything.

01-27-2004, 11:08 AM
so how do i figure port displacement lol

01-27-2004, 12:09 PM
Measure the external dimensions of the port to get a volume and then subtract that from you box volume. If you use the side of the box or the front of the box as part of the port, you don't need to add these (usually .75" due to box thickness) because you already accounted for that when you took the internal measerument.

If a port uses the side of the box and the front of the box, which most do in a typical slot design, then you don't need to account for the .75" on those sides.

01-27-2004, 04:44 PM
so in winsid, do you put in the cubic volume after displacement of subs and port and braces etc. or do you put in the volume with all those added to the air space? also, does port displacement mean just the wood needed to make the port or the air inside the port and the wood?

01-27-2004, 06:26 PM
port displacement is the wood, AND the space inside the port. Here is a pic of my box, the green outlined area is the actual volume of the box, as inputted in WinISD. Notice the ports, brace, and speakers are not figured into the final interior volume. Hope this helps.

01-27-2004, 06:28 PM
Oh, yeah, I know what Im doing, really. The ports on my box are not 20.35" long anymore. I forgot to delete that off the pic.