Need Router help

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Does anyone know of a site that shows you how to use a router properly to cut out circles and recesses for speakers, including tips on which bits to use? Also, do I need a plunge or fixed base unit? I want to get into speaker building, and would like to use some of the parts express boxes at first, then move on to my own cabinets once I get the hang of the electrical complexities. Either way, I'll need a router and circle jig to cut out the holes and recesses on the baffle blanks that PE provides.

I found this thread, but it's not enough for the ultra noob.

BTW, nice site Vikash. You are clearly good at this DIY hobby!
Router Help

Hello there,

You CAN use a fixed-base router to machine the holes. You would need to pre-drill a pilot hole larger in diameter than the bit you use, and ensure that your cut depth is less than the depth of the pilot hole each pass. Plunge routers are better suited to this task, given their design, but I have cut numerous circles with a fixed-base router successfully.

With respect to router bits, the best bits to use are solid carbide helical two flute bits.. These are NOT cheap, so any good two-flute carbide tipped bit will work.

Make sure you use hearing any eye protection...


make your own circle cutter, use a bit of MDF. Cut out the base plate shape in the MDF to allow your cutter to pass through and leave a long ear sticking out the side. A series of holes can be drilled to suit each new radius you need and an offset sideways will allow a small increment in radius. I'm sure if you saw a pisture of on it would be very easy to guess at sizes etc.
When routing out the speaker hole, leave the central area at full thickness and just rout a groove with OD to match your speaker. Then rout out the main speaker hole but take care as you approach the final cm as you will lose your central reference. A solution might be to stick the panel down with double sided, so as you cut thro' the two pieces will stay registered.

whiteside, spiral up cut bit, 1/4 inch 1/4 shaft, solid carbide. 14 bucks. whitesides are great bits and have over half a dozen of them and love everyone of them.

I tried cutting with a two flut straight edge and it seemed like it was restricting a bit and i broke a few bits, but with the spiral bit it cuts like butter and haven't broken it in over 15+ holes.

For using the circle jig, it comes with directions. I use a plunge base, and set the outside recess diamerter and depth on the router do the recess first then go and actually cut the hole second. alot easier then cutting the hole then use a rabbiting bit, expecially on a large sub where you would need an 1" rabbit bit.
AndrewT said:
make your own circle cutter, use a bit of MDF.

It's not attached, but you can easily see how.

An externally hosted image should be here but it was not working when we last tested it.
An externally hosted image should be here but it was not working when we last tested it.

I tend to do it in three or four cuts - cut a full 360 degrees and then drop it down another quarter inch to save breaking the bits. Cut 12 & 15" happily with that.


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Router help


Routers can be a great aid to the construction of speakers.

Routers can be used in a stationary position(router table..grooves..dados..etc.) or used freehand(using guides/shop aids with the router). Clamp all material to be machinedfreehand)....

Router Information: a library near you, a home build it centre like Home Depot, or a lumber yard, a specialty source like Lee Valley, plus other sources internet(look for web sites) ..forums etc. carry inexpensive books on the subject...

In addition to the responses allready expressed........tweeter holes(small) will require a small 1/4 " or 5 mil masonite(with a pin) or hardboard aid for the bottom of the router, large plates are ackward especially when using a power tool rotating at 15,000 to 20,000 rpm(gyrosopic effects and cutter grab(machining in the wrong direction) can throw you off if you don't expect it). You may want to remove the router bottom friction plate to attach, remember the distance from the outside of the cutter to the pin gives the hole size.

Larger plates are required for larger speaker holes.

As well: process... from the outside....cut the speaker rim recess first(round dado) next cut the speaker many cuts as you wish BUT DO NOT CUT RIGHT THROUGH... LEAVE .5 MM OR 1/32"(ON THE POSITIVE SIDE) LEFT AS FLASHING ... this maintains the cutout supported for the router..... remove the cutout with a knife or break it out, finish with a wood rasp ... its on the inside anyways and noone will see it....(or use a 1/4" laminate trimmer with a bottom bearing straight cutter to trim it out from the other side).....

Before you do that read up on it.

Be aware, be carefull, use safety equipment(dust masks, face shield, dust collector).. remember nothing can replace missing limbs above all RESPECT THE EQUIPMENT FOR WHAT IT CAN DO......use your muscles(almost aggresively) when operating...

have fun.....
I'm quite new to routing, so perhaps I'm missing something, but I made up this device which acts as a standard fence one way up and a fully adjustable circle jig the other (the pin fits into a predrilled hole of course).


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Router Help

Router tables with their fence are usefull for dados, and mitres.

I have found them a bad if not dangerous combination for making circles for speakers.

Explanation: first you have to create a lip for the speaker rim
then you may have to widen it
then you have to make another circle, several times to
cut almost through for the speaker.
in all these activities you are raising and lowering the
router cutter, repositioning the work piece etc.


Please know where you are working, know what you are working on, and monitor the process so you can stop if you run into an unexpected problem.

Never work blind with equipment that can cause physical injury.

The circle cutters submitted look great, smaller circles are a bit harder to improvise for but can be done with an adjustable lockable piviot.

Regards Dan
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