There has been a massive amount of development in progress with S3. So much that I don't have time to document, photograph, show measurements with explanations. There is a lot that I'm not showing, but here are a few snippets to give some idea of what has been going on behind the scenes. Last Saturday, a full day of testing concluded the acoustic design phase. A fully day of tweaking and testing is actually a drop in the ocean as far as this project is concerned.
You may notice a change in the directivity rig. The mouth of the horn or front of speaker is now aligned with the central axis, to ensure angles are more accurate. In future the whole rig is going to be rebuilt, since it's difficult to measure speakers like HE2 at this height. Most likely there will be a hydraulic lifting system and a more stable custom made turntable.
Conical ports to allow different port depths were tried. This is one of many:
Slot ports - lots of bog!
Just a few examples here of the work that has been going on.