February 9, 2015

Fibonacci pinecone inspired speakers

Note: I have now thrown these out because they sounded horrible (and I’ll explain why later) but it was a fun experiment!

I was trying to think of a good way to combat cabinet edge diffraction, improve uniformity in the polar frequency response, and reduce cabinet resonance. Suddenly this idea came to me - of slicing up a box and twisting it. I went to sleep that night with a pretty good idea of how it might look.

When I woke up, I went straight into SketchUp. Once I started turning the squares, I was reminded of this cool video that I saw on Khan Academy:

And so, I began referring to the speakers as “pinecones”. (Also porcupines, hedgehogs, and most disturbingly “porcucones”).

Build photos #

I am extremely lucky to be the son of a woodworker. I had planned out the basic steps of the build, but certain details are best handled by the experts. And it really helps to have two pairs of hands when working the drill press.

The above photo is part II of the glue and clamp process. I first made 4 semi-pinecones so that I could build on a stable base. Then glued the halves together.

In this smallest version of the pinecones, the smallest cube square is a 3/8" cube, which could really only allow a 1/8" hole. I was very pleased to have fit 2 pairs of wire through, since I will be using an active (DSP) crossover for the Vifa 2" fullrange and Dayton ribbon tweeter.