Nice.... I want some pictures if you do it :P
Find an app that generates sound frequencies, one is called "frequency generator". Find something nice and flat that has edges, this you will put on the speaker to absorb the vibrations from the frequency. A PRINGLES cap is good. Then get a bit of salt, put it in the cap and put it on the speaker when there is a frequency being played through the speaker.
Try with different frequencies and see what you find. You'll notice at cetain frequencies the pattern becomes were defined and quite "perfect".
Enjoy have fun Pangoli :D
thanks bro, i will definitely do it. please remind me if i forget
You gotta try it, you'll be pleasantly surprised, watch out for exaggeration though haha. I made a mess of the museum floors before, had a bit of sand to sweep up, the speaker was too loud..... I should have know lol.