Speakers work by converting electrical energy into mechanical energy (motion).  The mechanical energy compresses air and converts the motion into sound energy or sound pressure level (SPL).

When an electric current is sent through a coil of wire, it induces a magnetic field.

Specification:

Diameter: 40mm

Rated power: 0.5 (W)

Rated impedance: 8ohm

Frequency response: 45 (kHz)

Point: the whole point

Noise ratio: 92 ± 3 (dB)

Category: electric (moving coil)

Uses: radio sound toys

The composition: composition diaphragm

Magnetic circuit forms: internal magnetic frequency