If not, you can use online laser cutting service such as Outfab and cut it out for under a hundred bucks.
You can use old speakers for the components like I did, or purchase the speakers and amplifier from your local electronics store.
An old stereo system should have everything you need.
Step 1: Harvest parts
After taking the old speakers apart, analyze them and trace where the power and audio signals go. You'll need to know what to connect where.
Step 2: Design and Laser-cut
You can customize the design before you cut it.
If you don't have a laser cutter you can submit it to online laser cutting service such as Outfab (3sqf costs $92 including shipping.)
Step 3: Parts
For fastening the plywood I used 1/4" square nuts and 6/32 3/4" Torx screws.
I also sanded the wood to make it smooth but also so it fits in the slots.
By design, all slots were made smaller than the thickness of the plywood, so that everything can fit well after sanding.
Step 4: Assembly
I also put some hot glue on power and audio cable inside in order to prevent them from being ripped out.