I have the baby version of that speaker, the Genuin FS5. This is a ported box speaker.
The speakers you are talking about have a nice open sound due to their construction. They rock and bass is tight, not copious .
There is nothing unusual about their construction. That's just how some horn loaded speakers are designed. We don't notice this as we often don't flip the speaker over or read the brochure in full to learn about the design.
These speakers need space to sound good and its one of the reasons (cost too) I did not consider them as they were just too big for my room. Visually they are not that big but they do need space to sing. They wake up with amplifiers with modest, quality power ratings too.