Due to the large number of speakers I am building (12), templates are absolutely critical. For the monitors I built three templates. The first two templates are the exact size of the front panel of the speaker, with holes routed out where the drivers go.

The first template (the depressions template) has holes with a slightly large diameter than the diameter of the depressions (the area routed in on the drivers so that the faces can be flush with the panel). The second template (the holes template) has holes slightly larger than the driver holes that go into the front panel.

The purpose of these two templates is to let me use a router with a collar to route all of the driver holes.  I made the templates from 1/2" MDF. This is just deep enough to cover the collar completely. Thus, routing a front panel for the drivers becomes easy.

1) Align the depressions template and the front panel. Use the router with a 1/4" depth and a collar with a 3/4" router bit. Route using the template. This produces the inset for the drivers.

2) Align the holes template and the front panel. Use the router with a 1" depth and a collar and a 3/4" router bit (for simplicity I used the same bit for both). Route using the template. This produces the holes for the drivers.

Further, by flipping the templates horizontally you can produce mirror image panels with no setup work at all!

The last template is just a story stick to let me drill the holes for the ports. A story stick is just a stick with height equal to the side panel height and with two marks on it - one per port hole. I mark the spots to drill using the story stick. The holes are drilled using a drill press and a 2 1/8" hole cutter. 

The rear hole is positioned using a rule, since there is just one rear hole per speaker. The rear hole, a 1 7/8" hole, is used to place the binding posts. It is centered and put a couple of inches above the bottom of the rear panel.

Here are some photos of the templates. Note the labeling. That's important to stop brain spasms from interfering with your work.

Here's a picture of the router base with collar and bit