1Edge suspension (rubber)
2Cone (membrane) · makes sound by pushing air
3Dust cap
4Chassis (basket) · Ø 40 mm
5Solder terminals (+ red)

Paper or plastic cone, metal basket, magnet at the back, two solder terminals
Small type ≈ 40 mm diameter; sizes vary widely

Outputs

Speaker

In simple terms

What is this?

A small transducer that shakes a diaphragm with a magnet and a coil and carries sound into the air.

What is it for?

Turns the electrical signal into sound waves; music and speech become audible.

Where do you see it?

Phones, televisions and Bluetooth speakers.

How do you spot it?

A round cone with a frame around it and a magnet behind it; two terminals.

Caution:

Do not drive it straight from a pin; use an amplifier (amp) and turn the sound up slowly.

Technical definition

A transducer in which an audio signal passing through a coil in a magnet’s field pushes the coil and the cone attached to it back and forth. The cone vibrates the air and sound is produced. Its impedance is low, so it is driven by an amplifier.

Impedance8 Ω

Power0.5 W

Diameter40 mm

Schematic symbol Same in IEC and ANSI

IEC 60617: the drawing style used in Türkiye and Europe.

Pins 2

1Plus (+)End marked red or “+”; amplifier output+

2Minus (−)The amplifier's GND or minus output−

Features typical

Impedance: 4 Ω · 8 Ω
Power: 0.25–3 W (small types)
Driving: Audio amplifier (e.g. LM386)
Polarity: Sets the phase; irrelevant with a single speaker
Example part: 8 Ω 0.5 W, 40 mm

Common mistakes

Connecting directly to the pinA 8 Ω speaker tries to draw hundreds of mA at 5 V; the pin and the speaker are damaged. Use an amplifier.

Applying DCConstant DC heats the coil and pushes the cone to one side. Feed the speaker only a signal; add a coupling capacitor if needed.

Test with a multimeter

Test whether this part is good with the multimeter on the measurement screen.

Take a measurement

Where it is used

Audio amplifier outputDoorbell and alarmTalking toy

Try it in the Lab