how far the round port from driver?

i know the round port should be atleast the diameter size from the enclosure walls but how far should be from the sub? or it doesnt make any difference?

It doesn't make much difference.  Just be sure it is not up against anything.Support the12volt.com

cool! thanks bro

DYohn wrote: It doesn't make much difference.  Just be sure it is not up against anything.

Yes, a double thumbs up on this. I have successfully built my own ported enclosures using DIY OTS stuff at home supplies very successfully. On one build with a shallow depth box, the port was offset to exit the side of the enclosure, internally crossing behind the driver's basket within an inch. At 4" in diameter, having at lest 4" of unobstructed space at the end of the tube inside the box is all you need to keep in mind. Good luck, I love to see fellow experimenters at work!Life is too short to build slow computers or weak audio!