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3D Modeling and Redesign of Enclosure


Senior Member
Jun 16, 2021
Hey all, I got covid this last week. Not a lot to do but 3D model. I have been seriously considering the baffle and bracing of my existing nearfield monitors. My goals this year are to learn CNC, and I hope for this to be my first finished project. Luckily, most pieces are also small enough to fit on my 3D printer for testing. I don't have a lot of experience with baffle design, but I am inspired by JBL and Revel with their integrated waveguides, flared ports, and curved enclosures. There are a lot of advantages to rebuilding an existing set of speakers-- I know how it should sound, and if I don't like the result, it's easy to backtrack.

I started with an existing model, credit to Daan V for the high quality driver models and a clean enclosure. The slot version of this enclosure was originally discussed and blessed on Tech Talk. I would also be remiss if I didn't mention another direct design inspiration in the Parts Express Gallery. On to the show.
My vision board:
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My first model with a tube port and the original slot port model:
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New take, with extended baffle and semi-golden ratio curves.
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The slot improves chuffing, which I've noticed more with EQ and (unfortunately) no subwoofer. The box is designed with an Fs in the 50's, but not for boost. Air velocity is halved with the slot port at ~40watts, with a slightly lower Fs, according to a now-missing VCAD sim I found on the subject. The simpler option would be to flare the port on one or two ends and use the original enclosure. I hope this will add bracing, and I intend to add more in the design.

There's a long to do list, and I'm writing this for myself as much as someone who's done this before that is willing to check me.
1) Flare the woofer cutout and cover the screws
2) Determine assembly pattern
3) Dado recesses for better assembly
4) Update tweeter model to current waveguide (no hard edges)
5) Round over waveguide extension, or change it entirely
6) Check final volume, port dimensions
7) Potentially flip port to rear facing, redesign baffles, internals
8) Add cross-brace
9) Adjust top and bottom for assembly
10) Determine reversed screw hole locations
11) Practice modeling complex curves and intersections
12) Learn CAM
13) 3D print test baffles
14) Clean up files, repeat tests

...Lots to do, and I'm early enough to take suggestions. I will be sticking with Paul Carmody's design for the most part. No significant crossover or volume changes, just putting more effort into the original design principles.


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Senior Member
Jun 16, 2021
Dear slot port understanders. I have been at this for a bit and have questions regarding tapered ports. #1, Do I really have to learn hornresp? #2, what is more important, the area of the port, or the final exit for tuning? The length is correct, but the width now varies in accordance with the teardrop shape. Note that I am no longer building this to be a front slot port, but I now appreciate the value of the rear port and the value of a wider, better rounded opening.
Screen Shot 2022-09-11 at 10.53.24.png

The port itself is supposed to be 0.5"Hx5"Wx10.5"D. I guess I could increase the height of the opening slightly to compensate for the square surface area I'd lose. Not sure.

Anyways, here's the new front baffle extension. The side pieces have been adjusted to be wider in the front and narrower in the rear, to accentuate the teardrop shape. With this new slot port, I may add vertical and perhaps even an additional horizontal brace windows between the tweeter and woofer. My number one concern is the model of this tweeter is the old one, and I have not confirmed the new, curved edges on the tweeter waveguide. Those will be hard to model.
Screen Shot 2022-09-11 at 10.56.09.png

Another, better view of the rear opening
Screen Shot 2022-09-11 at 12.39.21.png

Another model, this time with a 1" thick slot and a 9.5" length. This would tune the driver to be very flat. No 50hz bump, but an F10 estimated to be ~35hz. Seems a bit too low to believe, but it would be nice for crossing to some sub(s). The real advantage IMO is it allows the driver to use its full power handling. 102dB est. is pretty good. T/S parameters are from Zaph Audio's measurements of the W4-1720, not the manufacturer spec.
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