DIY Speakers, a noob question

[Towen7]

I've been toying with the idea of a DIY speaker kit and have narrowed the list down to a handful. I noticed that some of the drivers require perfectly round holes with round recesses in th baffle. Others are round holes with recesses that are round on two sides but flattened on the others. The round holes and recesses I can handle with a variety of circle jigs, but how do you create the recess for a squared-off (for lack of a better word) speaker basket?

Here's an example of one of the drivers I'm asking about...

 

[Botch]

Re: DIY noob question

Entering "Jigsaw" into teh Googlz Imaj gives me a bunch of clown photos; WTF?? :think:

 

[Botch]

Re: DIY noob question

And, you don't even have to be that fancy, if you're patient. I cut two 6' x 9" ovals into the rear deck of my '71 Rustang, lying on my back in the trunk, in January @ -20 degrees F, using a hacksaw blade. No hacksaw, just the blade. Twue Stowey!

 

[Towen7]

Re: DIY noob question

A jig saw would give me a squared-off hole but what I need is a way to get a squared-off recess for the speaker to mount flush. Like these...

 

[-B-]

Re: DIY noob question

I'm curious too as I'd like to redesign the DIY kit I did a few years ago. I was thinking of trying an on wall speaker with the port on the bottom like Totem does with it's Tribe series.

 

[Batman]

Re: DIY noob question

I'd have to imagine there is a guide to do a straight pass with a router, that and the correct router bit should do the trick... :twocents-mytwocents:

 

[Towen7]

That's all I can come-up with. That would require making several very accurate passes though...

Two straight passes exactly the length of the flat sides at the depth of the recess. Each straight cut has to be perfectly parallel to the other, to be a precise length, and 90 degrees with the baffle edge. Then two curved passes at the same depth, joining the the two flats. Then two curved cuts to start the hole. Finally, two more straight passes, exactly parallel the first two and each other, to complete one hole. I'd need to get that perfect twice on each of five speakers.

I have a great guide for straight router cuts but it'll still require a pretty delicate touch.

 

[Batman]

I think I'd find a round speaker.... :teasing-tease:

 

[Orbison]

CNC machine? Did I win??? What's the prize??? :banana-dance:

 

[Batman]

I was going to suggest tracking down a CNC machine but that could potentially destroy ones budget...

 

[Towen7]

That... and the DIY nature of the project.

 

[DIYer]

You don't need to recess mount the woofer. It only applies to tweeters due to diffraction.

 

[DIYer]

If you really want to do it, first cut the smaller hole (1/2" to 3/4" smaller depending on the flange of the driver's frame dimension) that matches that driver shape (w/ 2 flat sides). Then using a rabbeting router bit, carve out the recess by tracing the hole you cut. When done with recess, if needed, cut the remaining part of the original smaller hole with jigsaw to make it round.

 

[Towen7]

Thanks. Cutting the hole freehand would make a less than perfectly straight/round guide for the rabbet. What about making a template?

I could start with two boards of equal width and cut a circle in one. Then I can rip the sides off of both boards, toss out the two sides with curves and glue-up the straight ones in their place.

That way I could clamp the template to the baffle and use a flush trim bit to create the hole in the baffle, and finally trace the hole with a rabbeting bit to create the recess. If the template works out I'd be able to duplicate the exact cut over and over.

 

[-B-]

I believe this device is what's commonly used, but exactly how I'm not sure. When I contemplated building my own cabinets this was on my list of needs. I'm not sure if it was only for round cuts or it could assist in this type of cut, I imagine it can assist is some fashion that Towen7 mentioned by making the round sides after the two straight lines.

 

[Towen7]

I have one of those and it'd work just fine for the round cuts and recesses. As noted you need to make the straight cuts first and join them with round cuts using this (or another style) jig. Getting those straight cuts aligned perfectly would be a challenge, but making them repeatable for multiple holes on multiple cabinets would be very time consuming... and easy to screw-up.

I really thing the template idea is the only way to go. After the work of making the tempate all you'd need is a flush-trim bit to make a bunch of identical holes.

 

[DIYer]

Thanks. Cutting the hole freehand would make a less than perfectly straight/round guide for the rabbet. What about making a template?

You could. It can be freehand cut and then sand or file it down a bit to take out the bumps. For a template, I would recommend plastic plate or something like that. To cut the first hole, you would need a straight router bit with the ball bearing above the blade so that you can trace the template from the top side.

 

[Wardsweb]

Two options: 1) build your baffle from two pieces. This will allow you to cut through the baffles and then glue and nail them together to get your recess. 2) make a gig for your router using some scrap whatever. Then use that as a guide to cut the recess into your baffle.

 

[Flint]

Most pros just use a template kit for their router to make a template and cut the hole out. It is extremely simple once you do it the first time.

 

[Maximo]

I would say route out what you can and then clean up the corners with a sharp chisel.