Originally Posted by Mrkazador
You can cut a hole with a jig saw if you really want to go cheap. The Ryobi RE180PL Is $99 at Home Depot all the time and works fine. That is what I used to cut holes in my enclosures. Maybe you can rent a router or jigsaw from Home Depot?
1. A jig saw won't recess drivers unless you stack another layer of sheet goods on top.
2. It won't let you trim to fit. Where you're not using miter joints two opposite sides of box shaped speakers have a dimension matching that of another panel plus twice the material thickness, where 3/4" nominal could be 23/32", 18mm, or 19mm. It's much easier to trim to fit than trying to make a panel that lines up exactly. You can use a flush trim bit in any router hand-held or table mounted.
Also if your budget is limited you definitely don't want to buy a commercial circle jig. A scrap of your favorite 1/4 to 1/2" sheet good (plywood, MDF, Masonite, etc.) with holes drilled for bit clearance, to mount your router (with counter sinks) and for arc centers works just as well and can be configured for odd dimensions (ex - metric) to get a tighter fit around recessed driver rims. The short 1/8" steel dowel pin that comes with Jasper jigs works great as a pivot, although you'll pay a lot less (like $1) buying one from a hardware store than you will on one of the store bought jigs that includes one.
For really small circles you can have the pivot pin under the router base.
The other thing worth noting is that while people like carbide spirals you can also use straight bits which cost less as long as you plunge while cutting (use multiple passes).Edited by Drew Eckhardt - 12/19/12 at 6:32pm