Internal bracing is added to help keep the enclosure rock solid & vibration free. In this view you can see how the innovative tweeter enclosure integrates with the two bass port slots. I'm not sure what purpose the two holes in this structure serve but they were in Tom Gee's schematic so I cut them just to be safe.

The next step was to bevel the front plate. This both helps the enclosure look good as well as cuts down on air turbulence & sound wave reflection especially around the bass ports.