Time to flush trim:
Trim the backs first, then the ends.
Random orbital sander + shop vac:
Now the filler process begins. I start with kitty hair for the screw heads on the ends and then move to regular Bondo and then to drywall mud.
I didn't want a pro-audio look with 1/2 roundovers, but paint doesn't stick to 90 degree corners so I went with a 1/4 roundover:
Jack hole time. Made this simple jig from cutoffs from the bracing:
And done. Had I though about it though, I could have just used a 2" fostner bit.
Laid out and drilled 3/8 holes with fostner bit for grill magnets:
Magnets epoxied in. If you look close you can see where I broke the edge of the 3/8 hole over with a 1/2 drill bit to give the filler a little more MDF to grab onto:
The magnets are covered with a layer of kitty hair and then a skim coat of Bondo. I went ahead and painted the bottoms with Duratex. I had some issues with the seams showing through even after 5 coats, so I pulled out all the tricks for the rest of the cabinets. First a skim coat of drywall mud:
Then high build primer:
Then 4 coats of Duratex. Also note I painted the area behind the ports black.