It's confusing because originally a port was a simple hole in the cabinet. That dates back to at least 1930. The use of ducts was rare until the 1950s, and not commonplace until the 1970s. To differentiate between a simple port and a port with a duct the term ducted port was used. Over time the word 'ducted' was dropped, considered redundant, because almost all ports were ducted. The handle ports on the SLA Pro and Otop 12 are technically ducted, with the depth of the duct being the thickness of the cabinet panel, but according to the original definition you wouldn't call them ducted ports.Emanuel Haumant wrote: They don't understand that effectively.
Vent=Port= a hole (like in Sla pro, omnitop12) in french "event laminaire"
And a a duct is when ther is a "tube" in french "event"
On the subject of what constitutes a tapped horn, this is the Danley patent.
Note in the pictures that there are no segments with constant area. If it's not tapered it's not a horn. As to how Danley got his patent, when prior art existed, it's all in the claims. The prior art from 1958 claims were related to the panel directly behind the driver, which is hinged at one end, allowing the size of the chamber behind the driver to be changed to tune the cabinet to the driver used. The claims later made by Danley were different, so the earlier patent didn't affect Danley.
As to what seems to be a serious lack of technical knowledge by some of your countrymen, it's no worse than here, where ignorance is often embraced with a fervor bordering on religious dogma. But Dr. Christian Heil would nonetheless be dismayed I'm sure.