A few years ago I came
across the idea of a subwoofer that will go down to theoratically 0 Hz.
Even better, the lower it gets, the more air gets pumped back and
forth, contrary to classical speaker designs.
As I just started using my then new 3D printer I started experimenting
and soon I bought a new Ø280mm speaker chassis:
I removed the speaker cone and started modelling parts for connecting
the speakers' driver to the blades through a swash-plate.
The basic set-up looks something like this :
As is apparent from these images I mounted the device in an old door
which I placed somewhere in the centre of my house.
The rotor was driven by a small electric-fan motor, which proved to be
I a next revision I need a speed-stabilized electric motor of at least
I opened all adjoining doors and connected the coil to a stereo
amplifier which I fed some signals from a simple sine-generator
software running on a laptop.
The result looked something like this (time-lapse) :
I'm not sure when I'll get around to improving this design. Design improvements would entail: -
lighter and thinner blades
- better clamping of the blades to the aluminum rods - stronger motor
- smarter connection between swash-plate and alu-rods