Best way to make holes for speakers.....

[Chuck Wintle]

I need to make some holes in 1 inch MDF to receive 7" and 4" speakers. I was thinking of making a template in thin plywood and using it as a guide for the routing the holes and slowly increasing the depth a little at time until the hole is made. Is this a reasonable method?

[Dan Mages]

I would reccomend either a router or even a dremel with a ciricle cutting attachment. Its easy to use and works every time.

Dan

[Bruce Page]

Sure, that’ll work but it seems like a lot of trouble and the router/ MDF will make a huge mess. Speakers usually have a flange that covers the cut hole, why not use a jig saw? You can cut almost as clean a hole if you take your time.

[Tim Morton]

I've built dozens of speakers using MDF, and yes a compass and a jigsaw is all you need. you could buy a circle cutting jig, but like was pointed out earlier...the flange will cover the hole. Just be careful to make it the right size.

[Gary Sutherland]

Seen any coverage of the car audio show/competition (I'm sure it has an official name but I don't remember it).

THEY were making holes for speakers by turning the volume up. Well, in the windshield anyway. 140,000 watts, 15 alternators and 40 batteries in a van! Holy earache, Batman.

gary

[JayStPeter]

It depends. If you need to flush mount them, use a circle cutting jig and router. I like to practice on 1/4" ply until I get the fit right. Once around cuts a hole so you can see how it fits over the mounting flange. If not, any of the previously mentioned methods will work. You can also use a fly-cutter at the drill press. Works great for tweeter holes, plus you can sharpen it after using it on MDF (unlike hole saws). Just make sure you clamp down the MDF. Personally, I like a circle cutting jig/router. Yep, it's messy, but the hole is nice and clean. Your 4" holes could be done with the fly-cutter.

Jay

[Chuck Wintle]

Jay,
I used the method you specified and the results were great. I made test holes in a scrap piece first , adjusting the circle cutter until the hole size was exact, then made the hole in the speaker and used a router to make the inset to flush fit the speaker.

[JayStPeter]

Cool, post some pics and let us know how they sound when you're done.

Jay

[Hal Flynt]

A few points.

I made some surround speakers, center and sub last year, and made them out of MDF too. I have a ZIP tool with a bunch of bits, so I bought the circle cutting jig for it, which was good for the 3-5" holes. This was the best use for the ZIP that I have found outside of cutting outlet box holes. THe 1/8" bits don't make as much sawdust as a larger outer bit.

The main point to remember when cutting a circle and your center point is in the waste piece. You need to plan for that last 1/2 inch or so, because when you cut through the last part, your center point is free to move DAMHIKT. One way I dealt with that was to drill a pilot hole all the way through and then cut just over half way on one side and thin flip and finish all the while using one of those "Sticky" router pads. Another is to use some scrap ply under the cut and fix your center point all the way through.


For the 12" hole for the sub, I cut the opening with a shop made jig that I fastend to the ZIP with the circle cutting jig "thingy". I drove a screw all the way through to a ply scrap as above. I made the mounting board for the sub out of a 3/4" piece and a 1/2" piece laminated with polyurethane glue. The 1/2" piece had a hole that was an inch bigger that the 3/4" piece and that created my mounting flange for a flush mount.

If I make some more, I think that I will make some round templates out of 1/2" MDF and rough cut the holes with the Zip or jig saw (I would have to clean up any jig saw cut I make), then flush cut with a flush cut router bit and template carpet taped or screwed in place.

[JayStPeter]

I have an attachment for my Dremel that makes it act like a rotozip. For cutting circles, I still prefer a router. It makes a mess, but I don't think anything is easier. On the last time round, you just unplunge a couple of times, then cut the little webs you leave with a utility knife and pull out the disk. The dremel was a little underpowered for MDF, so it went slower than with a real RotoZip, but surprisingly easy. If you're not flush mounting, the rotozip (or just a jigsaw for that matter) is fine. I also like the Dremel better for drywall, it's smaller and I feel like I have more control (sorta like a laminate trimmer vs. router).

If you build speakers often enough, the Jasper circle cutting jig is pretty cool. I hung out with some custom car audio installers for a while and this is what they used. They had a notebook with each speaker type they've ever used and which hole to use in the jig. I just keep drilling until I get it right :rolleyes: .

It's the tweeters that kill me. Trying to flush mount a ~1-3" (probably actually metric) circle. Couldn't get the fly-cutter to make a smooth enough template, ugghhh. Hole saws are never quite right. A hole saw hole with some tape around it as a template worked once. As did drilling a hole through the base of my old cheap Craftsman router so I could rout a small enough circle. Another reason to buy more routers :D .

Jay