Sound & Vibrations (DIY Paper Cup Speaker & Oscilloscope)
Source:
Wind a copper wire coil around a paper cup base and place a neodymium magnet inside. Connect to an audio amplifier — electrical music signals make the magnet vibrate the cup, creating a real working speaker!
Categorisation
Props & Materials Required
- •Paper cup
- •Enamelled copper magnet wire (28-30 AWG, 50 turns coil)
- •Strong neodymium disk magnet
- •PAM8403 3W mini audio amplifier module
- •3.5mm audio jack / Bluetooth receiver
- •Laser pointer + small mirror fragment (visual wave projector)
Step-by-Step Instructions
Wind the Voice Coil
Wind 50 turns of copper wire around the bottom of a paper cup to form a tight coil. Sand off enamel paint at wire ends.
Attach Magnet to Cup
Tape a strong neodymium magnet to the center bottom of the paper cup inside the coil.
Connect to Audio Amplifier
Plug wire ends into the mini amplifier board. Play a song from your phone or micro:bit sound board.
Feel Vibrations & See Laser Waves
Touch the cup rim — feel it vibrating! Shine a laser pointer at a mirror glued on the cup — watch sound waves dance as laser patterns on the wall!
Why It Works & Notes
Sound is vibration! Building a working speaker from a paper cup, wire coil, and magnet proves that electrical signals transform into magnetic vibrations that vibrate air molecules into audible sound waves.