So, if you took your Neuman KH310A to Denver, the cones would be pushed out by the sea-level air pressure sealed inside the enclosure?I guess I don't get it... Speaking of my sealed Neumann KH310 A, all seems sealed.
Neuman is based in Berlin, which is 112 feet above sea level. Denver is at an altitude of 5,280 feet. There is a difference of about 2.5 PSI in air pressure between the two locations. If those Neuman speakers were actually sealed, as in totally gas tight, the air pressure inside the enclosure could be 2.5 PSI higher than the air in a room in Denver, and this would result in a force of about 125 lbs pressing on the woofer cone from inside the enclosure, this would SURELY force the woofer cone to stick OUT, probably pop the tweeter diaphragm as well. And what about transporting those speakers as air cargo? There's a difference or 10.3 PSI between air pressure in Berlin and air pressure at 30,000 ft. in an unpressurized cargo plane. The speakers would explode! Think of 10 pounds pressing on every inch of the inside of the enclosure... an 8 inch woofer has a cone area or about 50 square inches, at 10 PSI that would be 500 pounds of force acting on that cone- that would NOT be ok.
There **HAS** to be a way for all sealed enclosure speakers to equilibrate their internal pressure to whatever ambient atmospheric pressure they find themselves in.