- you mentioned that slot area is often closed to cone area, do you have some link or paper which detail slot design rules (area and position) ?
I think there might be something in D&D's European patent application - but I'm not sure.
But my information was only a very rough comparison to aperiodic speaker concepts
with Variovent, whose area is rather small - compared to the cabinet size (roughly 80cm² at 50L volume).
During the design of the Directiva r2 it turned out that a slot area of almost that of the 5''-6'' woofer is optimal. In another project with a 10'' woofer I deliberately reduced the slot area a bit, so that it is only 60% of the woofer Sd - because in this way a better radiation is achieved.
There is no "real rule" for the relationship between driver area and slot area. Especially since the cabinet surface areas , cabinet dimensions and the position of the slots also still play a major role.
If one is "unscientific", one can summarize the few data points (the D&D 8c represents another data point) and classify very roughly in which ratio slot area to Sd should be...
- what would look the v and h sonogram of a front slot vented box (for instance a cube with woofer at the center and four slots around the woofer on front side) ?
Well, someone should simulate that
If the sound sources are arranged symmetrically, then hor and ver result in the same radiation - obviously.
Depending on the arrangement of the slots, the driver would be surrounded circularly or rectangularly by sound sources radiating with inverse phase. No idea how close the radiation then comes to an OB speaker without baffle (freely mounted driver).