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3D Modeling and Redesign of Enclosure

D!sco

Active Member
Joined
Jun 16, 2021
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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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