Once the cabinets were finished, the only remaining tasks were:

1. Installing the threaded inserts in the plinths for the carpet-piercing spikes. I mounted one near each corner, 1" in from the each edge. I also centered a third insert 1" from the back edge so I could compare three vs. four spikes. (Three spikes make it easier to level the cabinet, but four might be more stable.) I cut off the top 1/4" or so of each spike so the tops of the spikes wouldn't push against the veneer on the top of the plinth if I screwed them in too far.
2. Mounting the plinths to the cabinets. I used four 2" deck screws, taking care to position them so they penetrated the bottom edges of the inner front and rear panels.
3. Assembling the crossovers. I mounted the components on a 4 3/4" by 7" piece of 1/2" MDF. Dave's crossover instructions are very clear, but I had to modify the layout slightly because of the way I arranged the binding posts. Dave arranges all four posts in one row, while I used two rows (tweeter posts on top, woofer posts below.)
4. Adding a layer of polyester batting (included with the kit) to the top 15" or so of the center brace.
5. Installing the drivers.

Driver-ready cabinets with a layer of polyester batting attached to the center brace behind the drivers.

Crossover board mounted to the access panel. The components are obscured because the crossover schematic is proprietary.