Welcome to Adobe GoLive 6

There are two basic ways to cut circular holes in MDF. Use a plunge router with a circle jig, or use a drill and saber saw. Both cut holes that are sufficient for subwoofer construction. All of the holes are to be covered up by the driver, port or plate amp, so a super clean edge is not required.

The sole plate of the router is removed and a 1/4 inch plywood plate is made that has an extension on it is made.

A straight edge cutter is used. A hole is made in the plywood plate that is 7 inches from the edge of the cutter. A nail is driven into the center point of the speaker. Then the router is set to a minimal cut (1/8 inch), started, then plunged into the MDF. Rotate the router around the nail, set the cutter for deeper cut and repeat until the cutter breaks through. You should secure both parts for the final cut when the pieces will separate.

Make sure you try this out on a test piece of MDF first to check for hole size. Re-drill the hole for the nail as needed to make final size adjustments.

Some people only make a partial cut and use a saber saw for the final separation.

What you get with this method is a clean smooth cut.

Saber Saw Method

To use a saber saw, first use a compass to draw the circle, then drill a hole large enough for the saber saw blade to fit thru the hole with room to spare.

Then insert the saber saw into the drill hole and cut out the circle. Be a little careful as I found the saw speed to vary as I cut the MDF. Make sure the holes for the Precision Ports are large enough for the smaller end of the port to fit through the 6 1/4 inch openings. A smooth professional finish on these holes is not necessary as they will be covered up, but you must be careful so the fit is close to the required size, especially on the ports.