The Defiants - InDIYana 2019 Build

[KEtheredge87]

Hey Everyone,

Its about time I started a build log for my InDIYana entry this year, since I'm a good 1/3 of the way into building the cabinets. This year's theme is "Bare Minimum" referring to the number of XO components that we are limited to use (5 components in this case). I have decided to try a combo of an RS180P-4 woofer in a vented cabinet with a waveguide mounted RST28F-4 tweeter. Those drivers have held my interest and kept me from venturing off into the SB Acoustics territory just yet. I think the RS paper woofers look great, I've always wanted to do a build with them, and the extended smooth frequency response of those woofers ought to make my life a little easier on the XO as well. The waveguide I'm using is the Visaton WG148R, which fits the RST28 dome nicely once you remove the protective grill. I decided to make my own mounting cup to mate those two together, although I think civit has some DIY 3D printed adapters for this combo as well.

I'm a sucker for a bit of cabinet complexity, so I'm revisiting the curved sides AND top design aesthetic from my Jedi Mind Trick subwoofers. Rather than go full translam, this time I'm using tomzarbo's method of curved cabinets by laminating 1/8" HDF layers on to the cabinet subframe. In order to curve the top too, I added some internal MDF layers to the ceiling to allow at least 3/4" of thickness throughout the full path of the curve. Oh... and just to push the envelope one level further, I'm also doing a chamfered front baffle! Someone on Facebook predicted this year was "the year of the chamfered baffle"... which is partly goofy since they never really went out of style... but I'm happy to contribute nonetheless.

I'll attach some screenshots and BassBox models to show the general concept, but here's the rundown

The Defiants - InDIYana 2019 - Cabinet Specs
Outside Dimensions (containing box): 18" tall x 9" wide x 15" deep
Internal Volume, Vb = 0.642 ft^3
Predicted Box Tuning, Fb = 41.4 Hz
Predicted F3 = 42 Hz
Modeled Vent = 2" ID x 6" length (flush, no flare)
Materials: 3/4" MDF subframe, 6 layers x 1/8" HDF laminated walls
Front Baffle Thickness: 1.5" external + 3/4" subframe = 2 1/4" "total baffle thickness" << Needed to do this for the chamfered baffle look

Last but not least for now... credit where credit is due... I totally got the Noico 80 idea from JavadS 's "Rivalries" facebook thread. In general I don't really want to spy on other entries, but I generally recognize a good idea when I see one. Thanks bud!

[KEtheredge87]

More build pictures - Basic cabinet subframe with vented brace and standoffs for 3x5 crossover perf-board. Noico 80 layout for walls and cabinet surfaces. Curved cabinet glue-ups with cauls and prayers!

[Kevin K.]

I really like everything about these aesthetically. What software are you using for the renderings Keith, they look so real?

[KEtheredge87]

I really like everything about these aesthetically. What software are you using for the renderings Keith, they look so real?

Thanks Kevin! I use Autodesk Fusion360 for everything. The rendering mode does make some pretty darn good looking pictures!

[Kevin K.]

Thanks Kevin! I use Autodesk Fusion360 for everything. The rendering mode does make some pretty darn good looking pictures!

I thought that might have been what you were using. Agreed, really good looking renderings. I may have to take a harder look at Fusion 360 although sometimes it can be hard to teach an old dog new tricks.

Good luck on your project!

[scottvalentin]

These look awesome Keith - looking forward to watching your attention to detail through this build. Also, thanks for documenting everything like you do, I really enjoy following along and learning from what you share.

[tomzarbo]

I like the standoffs for the crossover pre installed. That's thinking ahead. Yeah, your renders look like a picture. Nice.
TomZ

[Jake]

Really nice work! Do you like these more than the Super Bees?

[KEtheredge87]

I managed to squeeze in an hour of garage time tonight, which was spent dealing with all the squeeze OUT from the titebond polyurethane glue on my second cabinet! I took a 1/2" chisel and gently scraped away at it until it was mostly out of the way. Special attention was paid to the MDF side of the joint, since I needed a smooth surface for flush trimming with the router after clean up. This is the first time I've used that polyurethane glue, and I gotta say the cured product reminded me of pork rinds... sticky, woodworking pork rinds!

For flush trimming, I again followed the TomZ method and used my jigsaw to remove a fair bit of the overhang, then came in with the router to finish the cuts on the front, top, and bottom edges. tomzarbo makes it look EASY in his video, but I was a bit nervous that I was going to tip the router into the cabinet somehow! This trimming method is fairly quick... and I imagine feels much faster if I don't have "pork rinds" to clean up before each new layer gets trimmed. Thank God Titebond II doesn't dry like that! Also, thank God for PSA sandpaper and angled cauls. Those are really saving my bacon when trying to clamp this cabinet to my flat workbench.

Pork rinds... bacon... I must be hungry or something

[KEtheredge87]

Really nice work! Do you like these more than the Super Bees?

Hi Jake,

Thanks for following along. I'll have to let you know after I finish 'em! Right now I've only had these in CAD and my brain, so you're witnessing the creative woodworking part of the process. Once I can get the cabinets done up nicely I'll shift focus to measurements and XO design. At the end of it all, I really hope I like them more than my SuperBees, just so I can continue progressing and improving as a designer. Each project is a new challenge!

[jhollander]

Looks good Keith! Who's not doing a chamfer? I'm an AutoCad user but can't get motivated to make Fusion work, I may need a tip or two in Indy.

[Wolf]

Keith- you have to let it dry first, then scrape it off with a chisel. It should not be sticky when cured after about 5 hrs, unless you mean the static-cling it also seems to possess.
Wolf

[KEtheredge87]

Keith- you have to let it dry first, then scrape it off with a chisel. It should not be sticky when cured after about 5 hrs, unless you mean the static-cling it also seems to possess.
Wolf

Good point Ben, I should be a bit more clear here. The cabinets were clamped up for 24+ hours and all the polyurethane glue had cured sufficiently. The sticky part was actually a bit of Titebond II PVA glue that had squeezed out between the HDF panels, and become sealed against the saran wrap on the bottom of the stack (with a dried layer of Poly glue on top - sealing the PVA off).

Thanks for the point of clarity!

[ernperkins]

Looking great, definitely want to see and hear them at Indy.

[KEtheredge87]

Looks good Keith! Who's not doing a chamfer? I'm an AutoCad user but can't get motivated to make Fusion work, I may need a tip or two in Indy.

Hi John, I'm happy to help with Fusion360. Not exactly an expert myself, but I've figured out enough to do some fairly advanced speaker cabinet modeling. I really like the program more than Google SketchUp because it works and feels much more like the professional CAD applications I have exposure to in my day job. Granted that happens to be Creo / ProE instead of AutoCAD, but the parametric modeling and general approach to 3D modeling is the same. If I could use my company's CAD work at home that would be great, but folks tend to frown on "personal projects" being entered on the company database! Thus it's the free and totally non-affiliated Fusion360 for me.