If you have a router and the right bits, you should have no problem duplicating it in plywood.
My son has a decent little Ryobi router and mating table. I machined an aluminum mounting plate for it to replace a plastic one, making it much sturdier. It's never going to be a pro-level machine, but got a lot closer. He's also got a good Reliant jointer, a Porter Cable 557 biscuit joiner, a PC 12" 15amp bevel mitre saw, and a few other woodworking tools so we can start making speakers when both of us have more money.
Our first project will be to make a slightly thicker grill for my recently re-engineered M&K V-90 sub. I'll let you know how that goes. That one is bigger, so we're going to use hardwood strips and the small biscuits on mitered corners to make a frame rather than a huge cutout from solid.