Not to thread jack... But could you explain this one to me?
I think i kind of understand what he means. i guess it can be kind of explained by an analogy of sorts. if you had a regular ported box with the sub firing forward and (heaven forbid) the port directly behind it firing back, then there wouldn't be much to control excursion because the air would escape before it had a chance to bounce off the walls a couple of times (fail explanation)
boxes help control excursion by maintaining pressure inside the box, without that pressure it would be like a free air environment, in which it is easier to reach the mechanical limits of the sub because there is less force pushing back up on the cone to keep it from bottoming out. so if most of the air escapes before it can pressurize, then you might as well have a free air environment...okay maybe not that dramatic, but you get the point.
^^that probably doesn't make any sense whatsoever, but i'm too tired to go back and read that shit right now lol.
i could just be talking out of my ass too who knows.
feel free to ask any more questions. i'm here to learn too
You're pretty close with that, not a bad explanation. I've been drinking so I cant really come up with a great explanation. I'll chime in tomorrow