Desktop Obelisk Micro Tower Speaker

These are sleek desktop satellite speakers, they have a very small foot print, but are tall enough to stand above desk-top clutter. Twin Tectonic BMR 28mm drivers give excellent dispersion, and the twin 65mm passive radiators give bass response down to around 110Hz.

Print instructions

I love the Tectonic BMR drivers, they sound great and I really like the way they look. I had some of these tiny 28mm drivers and wanted to find a design they would excel in. Modeling in WinISD I found they are a perfect match for the Dayton Audio ND65-PR. As built, the measured frequency response matches the model, and I've used a calibrated microphone to generate an optimized equalization curve

Here's a sound demo running with my P-CUBE subwoofer, listen with headphones:
https://youtu.be/HtjmpNfu1sg
The EQ settings used this video here are shown in the images.
My subwoofer design is here:
https://www.prusaprinters.org/prints/50923-p-cube-hi-fi-speakers-with-voxel-subwoofer
The amplifier used in the demo is here:
https://www.thingiverse.com/thing:4761687

If you like it, please hit like!

Specifications:

• 110Hz-20kHz Wide Dispersion Design
• Twin Tectonic BMR 28mm Active Drivers
• Twin Dayton Audio 65mm Passive Radiators
• 8 ohm impedance
• 40W Peak Power
• Dimensions 68mm x 238mm x 51mm
• Prints on Ender-3 Size Bed

Components, per speaker:
2x Tectonic TEBM28C10 BMR 28mm full range driver:
https://www.parts-express.com/Tectonic-TEBM28C10-4-A-1-1-8-BMR-Full-Range-Speaker-4-Ohm-297-2172

2x Dayton Audio ND65-PR 2.5″ Passive Radiator:
https://www.parts-express.com/Dayton-Audio-ND65-PR-2-1-2-Aluminum-Cone-Passive-Radiator-290-205

~300g printer filament of your choice

Speaker cable that will squeeze through a 5x7mm hole

16x M3 screws for the drivers, 4x M3 screws for the stand

Optional, 2x Standard 60mm x 60mm Steel Fan Guard:
https://www.parts-express.com/NTE-77-MG60-60mm-Metal-Fan-Guard-250-082

Enclosure Assembly:
Print with 3 perimeters and 60% infill, lying on its side, per the stl file. Poke out the integrated supports from the cutouts. Fit the stand, if you are going to use it. Run the speaker cable through the guide, seal it with putty or silicone. Fit the active drivers, wiring them in series. Remove the wingnuts AND the threaded washers from the PR’s. Fit the PR’s, making sure the internal cables don’t clash with the threaded rods. The front trim panel can be glued, or just fixed with blue tack, if you want the option of changing colors in the future.

Find out more about the speaker design and DSP amplifier setup, here:
https://www.instructables.com/P-CUBE-Speaker-System/