Quote Originally Posted by Old Guy View Post
I've never seen "have to" in print.

But do you really think technology has been static since the 70's? We did not have PC's to model speakers on then.

If you don't know what you are doing stick with sealed. But I can't see any reason not to use a properly designed vented box, especially if you actually measure them and build to that.
Yeah I was just going by the Altec literature.I forget the gentleman's name who designed the 411.It was with a 4" VC the only 4" that they made and recommended sealed enclosure.Don't worry Brad already pointed that out to me. I even considered using them in my VENTED box.