You can build a professional cabinet with sharp hand saw, a framing square and a eggbeater drill. A plane and chisel. Thats how some of the best furniture to date was build in the 17th century. If you looking to have an average life expectancy past 45 and finish these in less than 3 months, a few power tools would be cool.

The simplest and fastest process would be to go to Home Depot, or your favorite place to buy lumber that has these two things. Oak Plywood, and a Panel Saw. Buy the plywood you need for all the panels and have them cut all 12 pieces you need. buy iron on edgebanding and iron it on all exposed edges. nail up your cabinet with finish nails, fill the holes and finish.

corner cleats inside the box would make it stronger and you could blind screw everything from inside except the back panel.
A router would let you cut a perfect circle for the woofer and let you make a rabbet joint for the sides if you wanted. You can cut the woofer opening with a saber saw. You will need one to cut the horn opening and terminal block hole.

A skill saw with a good blade and a cutting guide would be as nice for cutting up sheet good as a table saw.

seriously, If have your panels cut on a good panel saw. All you need is a saber saw and a drill. From there, techniques and tools have no limits.

But remember.... The purchase of additional power tools for the aid in building project that is saving money. Are always Off budget!
so have it

Bill

fine print......
he who dies with the most toys wins. employees of the self employed woodworkers of America working in their back yards and outbuildings are not eligible. if you already had an accumulation of toolage but have since lost said toolage through divorce, please proceed to the bar. your friends are there. If you have one a similar contest in the past 3 months buy becoming deceased "with the most toys" you are no longer eligible.