How do you cut a speaker hole in baffle?

[andy__d]

Sorry if this is a dumb newbie question, but, how do you guys cut the hole in a speaker baffle board? (I’m trying to build a cabinet for an old amp chassis that I have). I’ve cut round table tops with a jigsaw in the past, but for those, you can cut from the outside in, through the offcut.

I was thinking of using a hole saw - I don’t have a 12“ hole saw, but I was thinking of cutting a big enough hole in the middle of the baffle with a 3/4” or 1” hole saw, to get my blade in, then cutting outwards to the line, like a spiral, then cutting out the “to the line” part of that spiral as I come back around. Not feeling awfully confident about cutting a good smooth line with a jigsaw, though, so I’m planning on sanding the last 1/4”. I’d prefer to use a coping saw to a jigsaw, but I couldn’t think of a good way to make that work.

Feels like I may be looking at this wrong, though - am I missing a trick? What do you guys all do for cutting a hole for a 12” Speaker?

 

[sds1]

You can make or buy circle cutting jigs for both jigsaw and routers. I've made jigs for both but ultimately prefer using the router. Depending on the router you may need a few passes at progressive depths, the jigsaw is obviously a single-pass cut. A jigsaw requires drilling starter hole while a plunge router is the easy way to start.

A jig can be this simple:

Hit up the Google for more ideas. My "final" router jig has center pins for 10", 12", 15" speakers.

 

[TomBrokaw]

Haven't actually done it myself, but I'd use a router and a circle jig.

 

[andy__d]

Thanks very much - that makes sense: I’d not thought of using the router for this, I’ll give it a go - thanks very much!

 

[Jsnwhite619]

If using a router and circle jig, do it with multiple passes going deeper each time around - maybe 2-3 cuts. And remember that it's going to break free at the very end, so be careful on that last pass. Two pass around and flip it over to finish will save your work surface from getting a new ring in the middle of it as well.

 

[Peegoo]

Another simple way is to draw your circle, drill a 3/8" hole just on the inside of the circle line, and then use a saber saw to remove the line all the way around (keep the blade centered on the line).

 

[schmee]

Another simple way is to draw your circle, drill a 3/8" hole just on the inside of the circle line, and then use a saber saw to remove the line all the way around (keep the blade centered on the line).

^This is what I usually do, but using the jig gets a cleaner hole. I usually have to drum sand the hole inside to take a lump or two out if I used the sabre saw following a line.

@Andy_D : But 1/4" excess would be way too much to sand off!
Also, determine what hole size you really want! A 12" speaker doesn't necessarily take a 12" hole!
Many are about 11-1/8" hole. Some are down to almost 10.5" hole. (If the speaker is rear mounted.)

If you are front mounting, you need to measure the diameter of the speaker frame where it sit's in the hole!

The main concern is leaving enough edge margin for the speaker screws to have plenty of room/wood.

 

[robt57]

Scintilla with and color [cut] on the lines.

If up cutting teeth blade, cut from back side and visa-versa for dwn cutting teeth/blade.

For me, the router get used for neck pockets and cavities pretty much. My router template body days are long past. Ask if you wanna know why and what I do a lot faster for over 15 years now..

 

[sds1]

And remember that it's going to break free at the very end, so be careful on that last pass. Two pass around and flip it over to finish will save your work surface from getting a new ring in the middle of it as well.

Cool tip about flipping it over. I figured I'd just have ongoing sacrifice but seems that can be avoided!

 

[robt57]

Cool tip about flipping it over. I figured I'd just have ongoing sacrifice but seems that can be avoided!

Flipping work and coming in from both sides highly recommended. Especially with String thu body work on fresh body.

 

[andy__d]

Also, determine what hole size you really want! A 12" speaker doesn't necessarily take a 12" hole!

Thank you, that was a near miss I’m glad I didn’t make - I need a 10.5” hole! Glad I asked the experts

 

[FXBDM 1832]

Simple board jig with a router, but I use a decking screw instead of a nail. Seems more secure to me. I also flip and do from both sides.

 

[FXBDM 1832]

Cutting a test hole in a scrap piece first is always a good idea.

 

[sds1]

Thank you, that was a near miss I’m glad I didn’t make - I need a 10.5” hole! Glad I asked the experts

AFAIK you need an 11.1" cutout for a 12" speaker.

EDIT: maybe "need" is harsh. I reckon it must be somewhat negotiable.

 

[robt57]

OP did not state if said baffle wood be would. or Ply would... be wood [wood chuck on my shoulder]

 

[Powdog]

Freehand with a scrollsaw and cleanup on an oscillating drum sander. Lots of garage woodworkers cheap out on the scrollsaw, which is one of those tools where quality makes a lot of difference. I’ve had a Swedish made Bosch for over 10 years and it scrolls perfectly without blade deflection.

 

[robt57]

I mention Scintilla, I have one for near 40 years, Bosch that was crazy expensive back then. But amortized out well. ;O

The load adjustable wheel on the blade [back and below] and the up and down cutting blade options allow for safe use in tasks where expensive materials are involved. But also in simple cutting tasks fast, easy, and predictable..

 

[tele_savales]

I made a really nice multi-size circle cutting jig for my router. Haven't gotten around to using as I'd like to fabricate something to plug my vacuum cleaner hose into as well.

 

[mk_716]

If you have a router and you intend to do more than one.
https://jaspertools.com/collections/all/products/model-200-the-original

I've used this multiple times and it works very well.
m.

 

[telel6s]

DIY Router jig. Just a long threaded rod attached to a center point made from a block of wood with a piece of round dowel inserted on the bottom.

I used the holes for mounting the baffle to the inside the cabinet to secure it to a larger base board. Kneeling on that board keeps things from moving around. Multiple passes. About 3/4 way through the final pass I just stood on the interior disc so it wouldn't shift as it became completely detached from the baffle. Of course if you don't care about the disc that gets cut out, you could simply drive two screws through it to attach it to the base board.