Make a speaker
A simple speaker coil

Drawing a spiral in Fusion: Spiral Shape in Fusion 360 quick tutorial - YouTube
Using your computer
Wiring
The amplifer that weare using is TDA2030 (can be fed up to -36V).

Test continuity using a multimeter
Use multimeter to test if there is shortcut from the two ends of the coil: Multimeter tutorial: measure continuity. Press tight your copper tapes.

Test amplifier using an oscilloscope

Processing code
Test sound using Processing:
import processing.sound.*;
SinOsc sine;
void setup() {
sine = new SinOsc(this);
sine.freq(440);
sine.play();
}
void draw() {
}
See turorials on generating sound in Processing (also check sound related libraries).
Using Arduino
Code
Gennerate a signal with tone()
