Bullet Speaker

Bullet Speaker

Maxim Duterre

Project Category:
Bookshelf Speakers

Project Level:

Project Time:
20+ Hours

Project Cost:
$500 – $1,000

Project Description:
The assignment I got was to design a speaker, I was free to do what I wanted but it had to have bluetooth. I wanted to work on my technical skills and challenge myself by having at least one mechanical movement inside of it. I designed this whole contraption with gears and belts which were supposed to drive a mechanical iris (similar to those found in cameras) but I couldn’t get it to work in time for the deadline. This feature is pretty much useless but it looks cool and I wanted to try and make it work. This was my first time making speakers and I taught myself as much as I could in a few months and this is what I came up with.

Design Goals:
At least one mechanical movement and it had to be aesthetically pleasing.

Driver Selection:
295-330 Dayton Audio DA135-8
275-020 Dayton Audio TD20F-4 3/4″

Enclosure Design:
Within the enclosure I had to find a way to hide and engineer all these tiny gears whilst making it airtight. As for the material, my initial idea was to make the enclosure out of mdf but because of all these gears and the time pressure I had to resort to my trusty 3D printer.

Crossover Design:
The crossover is a bit all over the place. There is one half inside the tweeter box and the wires go through the wooden legs all the way down to the box where the other part of the crossover is.

I’m rather happy with the results but there is still a lot I could improve on the aesthetic and engineering side. If I were to make more of them I would definitly get rid the mechanical components and just make a good sounding speaker. I would also make molds and cast them with some kind of resin because the PLA makes it sound a bit hollow but that’s because I only had the time to print it with a 20% infill.

About the Designer:
I’m a half French / half dutch designer born in Belgium. I moved to the Netherlands a few years ago and now I’m a first years student (2020-2021) at the Design Academy in Eindhoven. My end goal is to be a designer with my own little studio.

Project Parts List:

Dayton Audio DA135-8 5-1/4″ Aluminum Cone Woofer
Dayton Audio TD20F-4 3/4″ Soft Dome Neodymium Tweeter 4 Ohm


Add yours
  1. 1
    david downing

    Great looking design. Each element looks good. Would make any desktop or small console top stereo more interesting. Update when the iris works. It could be an essential “cat and kid finger” protection device.

  2. 4
    Timothy Siler

    Brilliant design. Not sure all process but hollow sound might be resolved by fiber fill adding a little at a time to tune for right sound. Then break in speaker Usually 100 hrs at mid power..

  3. 5
    Tim Diebert

    These look fantastic!!! I really like the rear passive radiator on the mid bass enclosure. Very creative. I’m surprised there wasn’t more talk about that radiator, like which one was used & what it was tuned to. But still an enjoyable build to read about. Great job I’m sure your end goal of designing in your own studio will come true. Keep ‘em coming bud!

  4. 6

    A controllable iris would make for a good tunable port, for different audio effects. If properly designed. Something to think about.. Great Job!!

  5. 7

    Very artistic, and very creative. I absolutely love the design. Considering this is your first time, I’d say you did extremely well! I have built effusive speakers, and still have not come up with anything this creative. How do they sound?

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