This post has been a long time coming. In the summer of my junior year of college, I found myself back at home with my parents, unable to get the sort of internship I was hoping for. I took a job at a local charitable foundation to get a little professional experience, but it wasn’t much of a technical challenge. That’s not to say that working there wasn’t rewarding – in fact, it ended up being one of the most important experiences of my life. But I still had a creative void that I wanted to fill. What’s more, I wanted to do something marketable, something I could apply to future engineering roles. I had just taken system dynamics and feedback control, and found that they piqued my interest in electromechanical systems. And I was (am) pretty into music. So, I decided to build a pair of speakers.
Before getting into this, I have to take a moment to apologize for the terrible photos in this post. The poor quality is partly due to the potato cameraphone I had in 2012, and partly due to the ineptitude of its operator. That’s hardly a bad thing, though, given the worse build quality of the speakers themselves. Fortunately, I learn from my mistakes. Sometimes.
The speakers would be a two-way design. Sure, full-range speakers would be easier to build and far cheaper for a broke college kid. They would probably even sound better, since I could get better components for the money. But I was fascinated by the electronic filtering I had learned about a semester earlier, and I wanted to put that to use. So, I picked a couple of relatively inexpensive drivers with complimentary frequency curves, and designed a crossover around them.
The crossovers are third-order, and were made with some online crossover tool. Yes, they are probably not optimized. But they still sound good to my ears.
The box and port dimensions were calculated with another online tool. In theory, Fs for the system is around 60 Hz. But after listening to them for a while, I doubt they extend that low.
The boxes were simply constructed from ¾” MDF panels. The joints are technically butt joints, though they were reinforced by additional MDF bracing inside. Additionally, for the sake of stiffness, I bonded two panels together to form the front baffles. The inner panel is undersized with respect to the outer panel by the thickness of the boards, which allowed me to construct a sort of rabbet joint along the outside of the baffles. Holes for the drivers were routered using a jasper circle jig, and premade, cut-to-length ports were dropped into place. Finally, plenty of foam was added to help prevent standing waves.
I may rebuild these at some point, or build a new pair of speakers altogether. But barring their looks, I’ve been totally happy with them so far – despite their modest components and even more modest build quality, they actually sound pretty good. I’ve managed to update their aesthetic somewhat as well:
