Hi, Greg,
Learned the following lesson from my floor monitor project:
Looking at the corner pieces, I guessed at either a 1/4-inch or 3/8-inch router bit for rounding the cabinet edges with the router bit.
I cut one cabinet's edges with the 3/8-inch bit, but while still uncovered, it looked too round, so I used the 1/4-inch bit for the remaining three enclosures.
Turns out that a 3/8-inch bit makes a better fit for the stock (Conrad nickel or original chrome) corner pieces after the cabinets are covered.
Do as you think best, but I like 3/8 inches for the outer edges, and 1/4 inch for the inside (facing the grilles) edges that do not receive corner pieces.
Best bet is to cut a scrap, lay a small patch of covering over it and check the fit. Then you can make a knowledgeable decision.
Always remember my life's lesson: "If it wasn't for f**king up, there'd be no up at all!"
Your project looks great. Nice work, my friend. Wish I had the time and space to do a pair of 2000S cabinets, but then I'd have to find and buy a good head - and figure out why I needed anything more than my 200S/415M in a 15 x 15-foot basement!
Warmest regards,