So, on to the port. The port sent with the kit is an adjustable one and is far longer than the specs call for. Below is a picture with the adjustable part separated. The red lines are the thickness of the cabinet and the further marking is the 3.5 inches the specs say the port should be. Should I use just the inner section and trim it, or should I slide the other part on and trim it and glue?

For final, use inner section trimmed to exact length.

For tweaking / tuning (which you should always do) start with longer length inner and slide outer part over it for different port frequencies. Listen or measure. Use only inner and trim down to exact size when you finalize on port length.

With the back done, I was able to install the port and binding posts and spike feet. I decided I wanted to hear how it sounded so I screwed in the drivers and connected everything temporarily and clamped the baffle. Sound is quite good for a single speaker in a large concrete floored shop. In a proper environment and with a glued-on baffle these should sound great, perhaps better than mine at home.

First DIY speaker, yes, but I work with wood all the time as a violin luthier. Second speaker should look better. There are a few things I did on this one that I will do better, mostly the baffle needs to go on before I veneer the top/bottom so I can cover it in one sheet each.

Had a setback due to inexperience with veneering. Needed to glue the baffle on then veneer the sides and baffle as one big sheet instead of individual sheets for each panel (due to rounded edges on baffle), so I wasted some nice veneer and had to rip it off. Luckily it was only 1 speaker that had been done. I need to return some veneer I hadn't opened and get a larger sheet, but haven't gotten to do that yet.