One can "see sound". Or... "A plate or membrane vibrating at resonance is divided into regions vibrating in opposite directions, bounded by lines of zero vibration called nodal lines." [wikipedia
These are figures are made with salt on this rig.
I have seen many ways I could build my own DIY vibrating Chladni
) but I was generally frustrated by the fact that one would generally have to sacrifice a speaker in the process, and I would need to have a super powerful sound amplifier. I wanted to
work with cheap off the shelf components
use as much of my own kit as possible (my conventional audio amplifier etc.)
avoid destroying the speaker
use a plastic membrane that is cheaper and requires less power (less noise for my neighbours)
This is how I built this rig. Sugru is ideal for this project because:
It provides a great acoustic contact that bonds to plastic sheet, board, metal, glass
creates a perfect seal between the speaker and the plate
you have time to make the whole set-up level before the sugru cures
can also create custom-made dampening pads for the contact with the table the rig sits on.
I don't need to destroy my nice speaker since I can cut sugru and re-use my speaker once the experiment is done
If you need to stock up on sugru
, you can buy it here and also from the Instructables store.
I recommend this instructable especially for educators as it makes a great intuitive
and hands-on introduction to acoustic with exciting experiments but without spending too much.
Going with this instructables, you can find classes that will teach you general concepts of standing waves, cancellation and many other phenomena.
- the physics Classroom
- UCLA acoustic
This instructable has been made by Cesar Harada
at TechShop SF
So lets get started!