Just finished the temporary stage wiring for the community fest

I used to build similar troughs for a volunteer-run bluegrass festival every summer. We found that adding a few 2x4 cleats inside the corners relly helped since that thin CDX plywood tends to warp the moment it gets damp. Even with pre-drilling, those screws can pull right trough if someone accidentally kicks the housing while running to the sound booth.

One thing I learned the hard way with our QSC stacks was to leave a little extra clearance for the connectors. If the L-shape is too tight, you end up putting alot of stress on the cable jackets where they exit the housing. I started using 6-inch wide segments for the top plate just to give the heavy-gauge SOOW cables some breathing room.

If you're dealing with mud, throwing a few cheap rubber mats under the plywood supports can stop the wood from wicking up ground moisture. Otherwise, by the second day, the wood gets soft and those level supports you worked so hard on might start sinking into the turf. It’s a lot of grunt work, but it beats having a short in the middle of a set.

I stopped using the closed L-shape boxes after a sudden downpour flooded our main feeder lines at a fairground gig a few years back. The trouble with solid plywood troughs is they can act like a basin if the grade isn't perfect. We ended up with several inches of standing water soaking into our Socapex breakouts beacuse the wood held the moisture in rather than letting it drain away. Now, I usally go with a sleeper system using pressure-treated 2x4s spaced every few feet with a sacrificial plywood lid on top. This keeps the runs off the wet grass but allows for plenty of airflow and drainage underneath. It also makes it way easier to inspect the jackets for nicks without having to unscrew the whole assembly. If you stick with the L-boxes, it might be a good idea to drill some one-inch weep holes every couple of feet. It’s a small tweak, but it prevents those heavy Berlin mains from sitting in a puddle if a summer storm rolls trough unexpectedly.

Forget the wood troughs if you're pulling serious amps. I’ve seen 4/0 AWG cam-locks melt right thru cheap CDX becasue there’s zero airflow in those boxes. I strictly use Yellow Jacket or Checkers Guard Dog ramps now. If you’re stuck with the DIY route, at least swap the plywood for some heavy-duty HDPE scraps or use 12-gauge SOOW cable to handle the heat. Also, are you running a 3-phase distro or just daisy-chaining off a generator? If it’s a Honda EU7000is, make sure your grounding rod is acutally hitting deep moisture or your surge protection won't do a thing when the stage lighting kicks in.