what's the proper way to model this type in Hornresp?

[freddi]

 

[Rademakers]

A 90 degree angled view would explain a lot.

 

[snappyturtle]

offset driver with the space occupied by the driver as a throat would give an approximation. looks like some old school TL take off

 

[freddi]

thanks your, inputs and time are appreciated

 

[luca4]

Try to search TQWT , it's seems similar .
Voight Pipe probably was the first speaker like a TQWT .
TQWT has at the end of the line a reflex tube-duct , Voight Pipe no (like this ...).
For many years an English company called Castle made TQWT with open end or with thin opening end .

Sorry for my English ...