Introduction: Making Sound Visible: Portable Cymatics Machine

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Have you ever wondered what sound would look like if you could see it? This project brings invisible sound waves to life! Using a simple portable speaker, some salt, and a surface stretched with cling wrap, you can create amazing geometric patterns that dance and change with music.

I call this the Portable Speaker Cymatics Machine — it’s a simple, low-cost way to visualize sound and explore the beauty of vibrations. Whether you’re into science, music, or just love cool experiments, this project lets you see sound in action!

Dhairya, Grade 7

Supplies

Common Supplies Needed

  1. Portable speaker (I am using an SKDY Ounce, but any small speaker will work, 115 mm to be exact)
  2. Rubber bands or duct tape (used to secure everything together)
  3. Cling wrap
  4. 2 tsp of Salt
  5. 3D-printed part (optional)
  6. If you don’t have a 3D printer, don’t worry — I’ll show you how to use a bowl instead for the same design

Step 1: 3d Print Pieces(if Applicable)

To start, you’ll need to 3D print two parts for your cymatics machine: a base to hold your old speaker securely and a cap to keep the salt from falling off the cylinder. Use PLA, ABS, or any material your printer supports. The base should fit your speaker snugly and provide a stable platform for the cylinder, while the cap will stretch over the top and keep salt from falling out during the experiment.

Attachments

Step 2: Bowl Tips(if Applicable)

If you don’t have a 3D printer, you can simply use a bowl instead, which works just as well for the experiment. The only thing to keep in mind is to place a tray underneath to catch any falling salt, because cleaning it up can be messy (Moms hate that). Also, make sure to secure your speaker with tape so it doesn’t move during the experiment, which could affect the quality and consistency of the patterns.

Step 3: Speaker Placement

Place your speaker on the base or inside the cylinder so that it sits firmly and does not move during the experiment. Make sure it is centered, as this will help the vibrations transfer evenly to the salt. You can secure it with tape if needed to prevent shifting, which could affect the patterns.

Step 4: Cling Wrap Placement

Next, stretch cling wrap tightly over the top of the base. If you’re using the 3D-printed setup, cover the opening of the base with cling wrap first, then place the printed lid on top. Secure everything with rubber bands so the surface stays tight and doesn’t move. If you’re using a bowl instead, cover the bowl opening with cling wrap and secure it firmly with rubber bands. The cling wrap needs to be smooth and tight, because any looseness will affect how the vibrations travel and how clear the patterns turn out.

Step 5: Put the Salt and Try It Out

For the final step, add a thin layer of salt on top of the cling wrap and turn on a sound source. If it is 3d printed I recommend covering the lid with another layer of cling wraps so it doesn't fall out. You can use a tone generator like onlinetonegenerator.com to play single frequencies, or try music, humming, or different noises. Start at a low volume and slowly raise it while changing the frequency. As the sound vibrates the surface, the salt will begin to move and form patterns, and each frequency will create something different. This is the fun part, so experiment, mess around, and see how sound literally turns into shape right in front of you.

Step 6: How It Works

When sound plays through the speaker, it creates vibrations that travel up into the surface holding the salt. Sound isn’t just something you hear, it’s a wave of energy moving through the air and through objects. Different frequencies vibrate at different speeds, and when those vibrations hit the stretched surface, they push the salt around. The salt moves away from areas that are vibrating a lot and settles in places that aren’t moving as much, forming patterns. These visible patterns are called cymatics, and they are basically sound waves turned into something you can see.