View Full Version : Pro's and Cons of External Port

06-01-2010, 07:05 AM
im running whats in my sig and after displacement (sub,port) my box is on the small side. In the long run I will have to build a new box but its just not plausible right now I've already dumped more $ than expected on the new setup. The subs are in one box with individual chambers and with the port length being 3x11.89 its taking up a lot of displacement not too mention its a lil too close to the back wall. Each chamber is 1.1 cuft and theres 2 chambers. I was gonna cut the middle wall to add space and change to external ports but is the formula the same?

06-01-2010, 07:08 AM
don't try and alter your box IMO, rather build a new one. As for external ports, the con is they get in the way of stuff in the car. the pro is they don't take up internal airspace in your box so the box can be smaller

06-01-2010, 11:22 AM
let me make sure I have this straight. You basically have two 1.1 cubic foot (internal gross?) boxes.
Your ports are 3" dia x 11.89 long?
If that's the case your ports are less than .05 cubic feet so you really wouldn't change anything by moving them to the outside.
Not sure about your sub displacement, but the answer to your question is if the box volume doubles, and the port doubles (a 2nd port, same size) the tuning frequency of the box will remain the same and your sound should change very little.
Moving the ports to the outside of the box may lower your tuning frequency slightly, but you may not even hear the difference.

06-01-2010, 05:31 PM
^Yes your correct and the sub has a displacement of .15 so after the sub and port displacement im under factory specs. Im just trying to optimize space. Yes i understand about building a new box but the back of a z doesnt have much to work with so the most i could gain is about .5 cuft