This project is sure to get your kids excited about sound engineering. With just a few household items, they can make an amplifier for a smartphone that really works.
Kids nowadays learn from the cradle that smartphones are pretty amazing. They can be used to listen to nursery rhymes, watch videos on YouTube, call Grandma, and so much more.
Today we’re going to build a little Gizmo to further enhance the smartphone’s functionality.
What? We can improve a fancy smartphone?
Yep, no fancy supplies required.
All my kids had a blast with this project, but my 4-year-old summarized it best of all, “I didn’t know we could do that!”
The Science behind the DIY Smartphone Cup Amplifier
Sound moves through space in waves and, as such, obeys the laws of physics. An audio engineer (or a sound engineer) uses those laws to
– improve the sound,
– reproduce music and voices,
– make sound effects,
– manipulate recording instruments, and
– develop and build technology that helps us hear things in a better or different way (i.e., microphone, amplifier, etc.)
For example, we can slow down birdsong to hear all the different notes in it, or build a room that lets you hear what someone’s whispering on the other side… cool, right?
An amplifier is a device that uses the science of sound waves to help us hear richer, deeper, louder sounds. The first professional amplifier was invented in 1912 by Lee de Forest, an American inventor with a Ph.D. in physics and electricity, who became known in history as “the father of the radio and the grandfather of television.”
But did you know that you don’t need any fancy equipment to experience the power of amplifying? Go outside with a friend who can stand 20 feet away from you and shout, “I love science!” Now do the same but cup your hands together around your mouth. Did your friend notice that cupping your hands amplified your voice?
When sound waves are created (i.e., you say something), they want to spread in all directions like ripples in the pond. When you cup your hands around your mouth, you channel the energy of the sound waves in one direction – straight out. Therefore, your shouting can reach a person standing in the distance better.
The following project lets you play with the science of sound waves and explore the same concept. But instead of cupped hands and our own voice, we’re using two paper cups and music playing from a smartphone.
The cup amplifier gathers sound from the smartphone and projects it in one direction – out of the cup openings. As a result, the sound is louder and, as you will notice in our video, richer.
Let’s begin the project!
DIY Smartphone Cup Amplifier
What You Need
Two paper or plastic cups
Paper towel roll
Glue or tape (you might not need it)
What To Do
- Trace the outline of the circle on the end of the cardboard roll onto the side of each cup with a marker.
- Cut inside the outline. If the paper roll doesn’t fit, with tiny snips, increase the opening. If you make the gap too big, you will need tape to cover the extra space.
- Next, trace the outline of the bottom edge of your phone in the middle of your paper roll.
- Cut a slot for your phone to fit in so it wills tand up in the paper towel roll. Make sure to create a flap and bend it inside. It will provide nice support for your phone.
- Attach a cup to each end of the tube and check how nicely it fits. As you can see, our cups fit very snugly, so we didn’t feel like we needed to apply glue or tape.
Later though, we decided to apply a bit of tape to one particular spot just to see if it would make any difference. If it did, we didn’t notice.
Finally, turn some music on and listen to it with your phone first outside and then inside the amplifier.
What do you think?
We definitely felt that the amplifier did its job to amplify the sound for us. That exciting theme music came out richer and deeper!
P.S. As always, feel free to decorate!