Measure the dimensions of the chosen monitor cabinet design, including the baffle (speaker-mounting section), on the plywood sheets and mark the cutout lines with the carpenter's pencil. Cut out the desired dimensions using a table saw or circular saw. Sand down the cuts with medium-grit sandpaper.
Place the chosen monitor driver and any other components (tweeter, crossover) on the baffle and draw an outline around their circumferences. Be sure to mark any mounting holes in the speaker and component flanges onto the baffle as well.
Remove the speaker and any components from the baffle. Draw another line within the drawn outlines to allow half an inch of clearance from the mounting holes. Cut along these second lines with a jigsaw or saber saw. Sand down the cuts.
Attach the side pieces of the monitor to the bottom piece with wood glue. Attach the top piece to this frame with the glue as well. Drive the wood screws into these joints with the drill and the screwdriver bit. Attach the baffle to the front of this structure in the same manner.
Drill the mounting holes for the speaker and components on the baffle with the drill bit chosen for this purpose. Mount all components onto the baffle with the bolts and T-nuts.
Cut the speaker wire with the wire cutters into the lengths needed to link the speaker and components as well as to run a signal wire to the back or the side of the monitor as needed. Strip off one inch of the insulation from the cut ends of the speaker wire with the wire strippers.
Attach the exposed leads of the linking speaker wires to the terminals of the speaker and the components with the soldering gun and solder. Attach one end of the signal wire to the driving component in the same manner.
Drill a hole into either the back or side section of the monitor for the speaker jack plug using the ¼-inch drill bit. Install the jack plug with pliers. Solder the other end of the signal wire to the jack plug.
Glue on the back section to the monitor speaker enclosure and secure with wood screws. Smooth off the entire enclosure with fine-grit sandpaper to prepare for finishing.