Make a Homemade Cell Phone Speaker
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Build a simple homemade cell phone speaker using cups, cardboard, and tape to amplify sound and explore basic acoustics through hands on experimentation.

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Step-by-step guide to make a homemade cell phone speaker

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How to Build a DIY Mini Bluetooth Speaker at Home || DIY Portable Bluetooth Speaker

What you need
Adult supervision required, paper cups (2), pencil, ruler, scissors, sturdy cardboard piece, tape

Step 1

Clear a flat table and lay out all your materials so you can reach them easily.

Step 2

Use the pencil and ruler to draw a large fan shape on the cardboard about as wide as a cup opening.

Step 3

Cut out the fan shape from the cardboard with the scissors while an adult watches.

Step 4

Roll the cardboard fan into a cone shape so one end is small and the other end is wide.

Step 5

Tape the long edge of the cone to hold it closed so it keeps its funnel shape.

Step 6

Trim the tiny tip of the cone so the small end makes a hole that will fit into a cup mouth.

Step 7

Cut a horizontal slot near the rim of one cup that is wide enough to hold your phone snugly while the speaker faces into the cone.

Step 8

Push the small end of the cone into the mouth of the cup with the slot and tape the cone to the cup to make a tight seal.

Step 9

Fit the wide end of the cone into the mouth of the second cup and tape them together to form a bell-shaped amplifier.

Step 10

Turn on a song or sound on your phone at a low volume.

Step 11

Slide your phone into the slot with the speaker facing the cone so the sound can travel into the funnel.

Step 12

Move the phone forward and backward a little to find the loudest spot and try flipping or removing the outer cup to hear the difference.

Step 13

Take a photo or video of your finished speaker and share your creation on DIY.org

Final steps

You're almost there! Complete all the steps, bring your creation to life, post it, and conquer the challenge!

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Help!?

What can we use if we don't have cardboard or disposable cups from the materials list?

If you don't have sturdy cardboard to draw the fan shape on, substitute a cereal box or poster board to cut the fan, and if you lack cups use two matching yogurt tubs or trimmed plastic bottles with similar mouth diameters.

My cone keeps falling out of the cup or the speaker sounds muffled — what should I check?

Check that you taped the long edge of the cone to hold its funnel shape and firmly tape the small cone-to-cup seal (the step where you push the small end into the cup), trim the tip for a snug fit, and reposition the phone in the slot while playing a sound to find the loudest spot.

How can I adapt the steps for different age groups?

Have an adult pre-draw and cut the cardboard fan and cut the cup slot for preschoolers, let elementary kids roll, tape and trim the cone themselves under supervision, and challenge teens to experiment with cone angle or cup material to improve amplification.

How can we extend or personalize the homemade speaker once it's assembled?

Decorate the cups and cone with markers or stickers before assembly, try stiffer cardboard or different cup materials to change the sound, and test variations by moving the phone forward/back as described to compare which design is loudest.

Watch videos on how to make a homemade cell phone speaker

Here at SafeTube, we're on a mission to create a safer and more delightful internet. 😊

How to make Speaker at Home Easy Way - Using Cardboard and Old Mobile Charger

4 Videos

Facts about acoustics and sound for kids

♻️ Cardboard is lightweight, stiff, and easy to shape, which is why it’s a favorite material for DIY acoustic projects and speaker cones.

📣 A paper or cardboard horn focuses and directs sound waves, helping a tiny phone speaker seem louder without extra power.

🔊 Making a funnel or cone can boost perceived loudness by about 3–6 decibels — enough to notice in a quiet room.

📱 Most smartphone speakers are only a few centimeters wide but still produce sound across much of the human hearing range (about 20–20,000 Hz).

🧪 The hollow space inside a cup acts like a resonator that can amplify certain pitches, similar to how a guitar body or violin works.

How do you make a homemade cell phone speaker?

To make a homemade cell phone speaker, cut a slot in a small piece of cardboard wide enough for your phone to sit upright. Attach one or two paper or plastic cups so their open ends face outward to amplify sound — tape or glue the cups to the cardboard. Place the phone in the slot with the speaker facing into the cup. Test different cup sizes, distances, and angles to improve volume and clarity while an adult helps with cutting.

What materials do I need to build a homemade cell phone speaker?

Materials needed: two paper or plastic cups, a small piece of cardboard or stiff paper, tape (or glue), scissors (for adult use), and a smartphone. Optional extras: a toilet-paper roll, hot glue, decorative stickers or paint, and a ruler or marker for measurements. For very young children, prepare pre-cut parts and replace sharp tools with safe alternatives while supervising closely.

What ages is this homemade cell phone speaker activity suitable for?

This activity is generally suitable for children aged about 5–12. Ages 5–7 need close adult assistance for cutting and careful assembly; 8–12 can handle most steps with supervision. For toddlers under 5, focus on decorating a preassembled speaker and exploring sound rather than construction. Adjust complexity and supervision based on each child's fine motor skills and attention span.

What are the benefits, safety tips, and variations for a DIY cell phone speaker?

Benefits include hands-on learning about acoustics, improved fine motor skills, and creative problem-solving. Safety tips: supervise cutting, use blunt scissors for younger kids, keep small parts away from toddlers, and limit phone volume to protect hearing. Variations: try different cup sizes or materials, use a paper towel tube as a horn, build a two-cup stereo setup, or decorate the speaker to combine art with science.
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