I started by ripping some 3/4" plywood to width at the table saw.

Then I cut it to length at the miter saw.

I began joining all 4 sides with glue and brad nails. 

Once the sides were joined, I measured for the bottom pieces of plywood and cut them out at the table saw.

Before attaching the bottoms to the rest of the box, I found the center of each bottom piece, cut the PVC pipe to size, and then located the PVC cups on each bottom piece. 

Now that the bottoms were mapped out, I attached them to the rest of the box using glue and brad nails. 

Then I used my combination square to find the center of the side of the box, leaving a saw blade width between the two marks. 

With the center marked, I took it over to the table saw, lined up the mark with the blade, and cut it in half along all four sides. 

Using the marked out cup location from before, I pre-drilled some holes from the inside and then countersunk those holes on the outside for some screws. 

Next, I used some epoxy to secure the PVC cups to the bottoms initially, following up with some screws from the underside. 

Then I used a razor blade to cut some leftover speaker box carpet to size.

With the carpet cut to size, I used some spray adhesive to attach it to the bottoms of both sides.

To keep it all together while stored, I added two lasps to the box on opposite sides.

Next, I added a fresh coat of paint to the washers.

Tip: Use some neon or really bright spray paint when painting the washers - you'd be surprised how difficult these can be to find in the grass!

To give the box a little bit of protection, I applied a few coats of wipe-on poly. 

And lasty, I added a pair of leather handles to the box for easy carrying! That's it!