I wanted to have the top and bottom pieces wider than the box itself. Sort of like a table top, but with only about 1/2" over hang all around. I also wanted an extra piece on the front baffle for flush mounting everything.
The top and bottom pieces are 3/4" mdf and the front baffle cover is 1/2" mdf. I have some more good news in prepping the mdf for paint (this is not for the mirror coat stuff mentioned above). I've used a lot of different primers on bare mdf and it takes many coats to seal it up. I've used diluted wood glue to seal the mdf before primer and still needed 2 coats.
Well, I just happened to stumble across this Krylon rust primer formula:
BARE MDF, no wood glue sealer......1 coat of this primer did the job. That's no joke. And this stuff came out of the can like no other spray can I've used. Very good pressure and it lays down some serious coverage. Matter of fact, on my front bare mdf baffles, after 1 coat I was ready to paint. I barely had to sand anything at all. But I had them standing straight up while painting.
On the tops and bottoms, I laid them flat which didn't give me nearly as nice of a primed finish because of how I held the can. BUT I still only needed 1 coat, I just had to sand it more than the baffles.
1 coat on bare mdf: It wasn't quite dry yet in this photo, but you get the idea.
You can see that small piece of sandpaper laying there. That one side of paper is all I used on both front baffles (not pictured). Literally 30 seconds on each one was needed if that. I found the stuff at Meijer's. It's like a Walmart, I believe they are nationwide. Not sure if HD or Lowes carries Krylon.
Stay tuned for a way to put some cheap feet on your subs.