Ok, back to both
That concludes separate sections. The rest of the process is the same for both the Pretty One™ and the Rustic One™.
You’ll notice in my pictures I’ve got either wood blocks or pieces of wood going across on the inside of the skirts. The metal sheet that will have all the components will sit on these supports.
Cut 2 (or 3 if you’d like a middle support) pieces of wood that are the same length as the inside of your enclosure, slather wood glue on one side of them, clamp those glued up sides to an inside… side of the box, and let it all dry. Those pieces of wood should be significantly shorter than your skirt walls – if your skirt is 3″ tall, they should be 1″ or so and you’ll want to position them about 1/2″ below the top of the skirt.
I find that using a wood block to just rest the support on that is cut such that the stack of wood is about 1/2″ below the top is the best way for consistency. At minimum you’ll want to do two opposing ends. In any case, you should end up with something like this.
One thing to note about the above image is that I added a support going through the middle. This support is not needed, but I wanted it due to knowing that there would be significant weight on this particular amplifier. If you choose to do that, make sure to position it so it will not get in the way of any mounted components on your panel and you’ll also want to think about drilling out a large hole for wire to pass through. For that particular amplifier, the board also separates the power section from the signal section of the amplifier, though will have no affect on audio quality.
You can also use smaller wood blocks as some of the other pictures here show. Those are a bit less robust and, in my opinion, harder to align correctly. However, using a similar approach you can do that too.