Mini Devastator Build, with Clear Front Panels

Now that I have these running in my theater, its time to do a writeup.

Thanks to @LTD02 for the devastator v1 design, and all the other amazing designs and help he gives here.
Thanks to @Red Five for the mini devastator design, along with many other devastator variants.

More devastator information can be found here:
The Devastator Index
The design and cut sheets for the mini can be found there as well.

I started by picking up the mdf at lowes. The cutsheets are designed around 2’x4’ sheets, so I had lowes break the 49”x97” sheets down on their track saw. 3 cuts per panel are free. I had them cut to 24 1/4”, so I could cut to exact dimensions on my table saw.

Step one: clean up shop and prepare for dustpocalypse. I prefer to cut mdf outside, but it was 20* and snowing.


Set up table saw to 24” and rip all 14 panels.






Here are the cutoffs, showing lowes’ cutting tolerance:

One sheet was slightly under 24, but not a problem since one sheet on the cut sheets isn’t used full width.

Now start cutting to length. My table saw is only good to 25”, so I used a circular saw for all longer cuts:


The first night, I finished all table saw and circular saw cuts. I cut 2 additional 28” long 1.5” strips and one 24” long per box, to use for window mounting. In hindsight, I should have used 2” strips because I used 2.5” screws.


One modification to the cut sheets: I would add another 1/4” to the side panel length. This would have made the finishing process much easier.

Use a miter saw to cut all 1.5” strips and 2x4’s to length. Could be used for horn rails as well.


Now I have two mini-devastator flat packs:


Time for some router work. First, cut the driver mounting hole in the baffle.


Since I’m putting the front window on, lets add a 3/8 roundover:


Use the driver to mark mounting hole locations. I really like threaded inserts for driver mounting. Plus, I can install them blind in this case for a perfectly smooth baffle face. Drill the blind holes using a drill collar, or since I couldn’t find mine, electrical tape wrapped around the bit to mark depth. Recess holes slightly with a large bit spun in reverse.

I like to install the inserts with jb weld as added insurance:


I test mounted driver to see how roundover would look:


Now for the horn rail clearance. I cut them for 1” clearance. I marked out the cut, and cut slightly small with a jig saw. Then I used scrap pieces of mdf clamped on to make a perfectly square template. I used a top bearing flush trim bit in the router. After the first one, I used it as the template for the other three.

Add 3/8 roundovers to both sides:

I also added 1/8 roundovers to both sides of the top.

Now for the window mounting rails. I started by putting a 1.25 radius on the bottom corner of each. Then used a 3/8 roundover on the bottom and a 1/8 roundover on the top.
I also ran the roundovers on the 24” chunks for the top, will be cut to length later.