15.26 Acoustical Extraction

Besides the highly individualized hand jive style of extraction using a screen, the question arises as to how much support we might expect from music, or other acoustical dry sieving techniques.

Having a keen inquiring alleged mind, I was enraptured by the thought of what my most favorite songs might shake out, if properly connected to sweet Mary Mary’s essential essence, sooooo, how could we resist experimenting? Hee, hee, hee, here are the results of our quest to find out.

May we start in the original spirit of the game by understanding that part of the skunk pharmers little game amongst ourselves, is as much as possible, to create everything possible from scrap in one of our treasure piles.

I scored a supply of 1 1/2 X 3/4 X 96″ finger jointed mahogany for $0.99 a stick from a surplus re-cut lumber store, grabbing all they had in stock for sieve frames.

Another $2 got me a badly curled sheet if 1/8″ mahogany plywood. Such a deal!

As a starting experiment, we used a 10″ woofer mounted to a diaphragm, to bounce a sieving tray.

The sub woofer came from a Maranz stereo base reflex speaker, that I purchased used in 1967 for $15, and had gathering dust in storage since around 1980.

I used a 100 Watt amplifier Bob built from components in the 80’s and was also sitting around gathering dust.

To our chagrin, the sieving action generated by taped music was not as productive as we hoped, leading us to switch to a signal generator, to determine the best frequencies for our purpose.

Surprisingly, the wooden harmonic test sled design produced the best sieving action at 30 Hz.

Here is the shaker base, along with the shaker tray and sieve.