With regard to the tuning port size/type, we looked at ducted ports, but Jerry pointed out that the speaker only "wants" to see a certain vent size, and doesn't really "care" how you achieve it as much as that it GETS the size it needs and can operate through it without having to work at it.

That said, we figured out it would take THREE large flared ports to accomplish the same thing we did with the horizontal vent, and the cost just didn't outweigh the advantages (if any).

When you listen to the 704-8A in the Stonehenge V enclosure, it performs almost effortlessly in the LF region (it does in the HF region too, but we're not talking about that right now), as does the "G" in the Model 17 and the "H" in the Model 18. So MANY speakers seem to have "work" hard to get the LF out to the listener - the 704-8A in the SH V box doesn't have this problem. In fact, the LF performance is very similar to listen to as the Model 19.