Description
🔊 77 mm Speaker, 8 Ω / 3 W
This 77 mm round speaker has an impedance of 8 ohms and a rated power of 3 W. Compact and easy to integrate, it is suitable for small amplifiers, radios, intercoms, alarm systems and DIY audio builds.
Its metal chassis provides rigidity, and the two terminals allow quick soldered connections.
⭐ Key features
- ✅ Compact 77 mm format
- ✅ Standard 8 Ω impedance
- ✅ 3 W rated power
- ✅ Sturdy metal chassis
- ✅ Two easy-to-solder terminals
- ✅ Compatible with many amplifier modules
- ✅ Ideal for audio repair and prototyping
🔧 Technical specifications
- Type: electrodynamic speaker
- Shape: round
- Outer diameter: approximately 77 mm
- Nominal impedance: 8 Ω
- Rated power: 3 W
- Connection: two solder terminals
- Chassis: metal
- Use: reproduction of music, voice and sound signals
- Required amplifier: compatible with an 8 Ω load
⚙️ How it works
The speaker converts the electrical signal from an amplifier into mechanical vibrations and then sound waves.
Do not connect it directly to a DC power supply. An audio source alone—such as a phone, Arduino or Bluetooth module—may also provide insufficient power; use a suitable amplifier.
🔌 Wiring guide
| Speaker terminal | Amplifier module |
|---|---|
| First terminal | Positive speaker output SPK+ |
| Second terminal | Negative speaker output SPK− |
- Switch off power to the circuit.
- Connect the two terminals to the amplifier’s speaker outputs.
- Check that the amplifier supports an 8 Ω load.
- Start at low volume.
- Increase the volume gradually, without causing distortion.
Follow the + and − markings when present. Reversing polarity on a single speaker usually does not damage it, but can cause phase cancellation when multiple speakers are used.
🎛️ Compatible amplifiers
This speaker can be paired with various small audio modules, including:
- PAM8403 modules
- LM386 amplifiers
- Amplified Bluetooth audio boards
- MP3 player modules with amplified output
- Small intercom or alarm circuits
With a bridge-tied-load amplifier such as the PAM8403, connect the speaker between the two outputs of the same channel, for example L+ and L−. Do not connect either output directly to GND.
🤖 Electronics projects
- Voice synthesis with Arduino or ESP32
- DIY MP3 player
- Radio and audio receiver
- Electronic doorbell
- Alarms and alerts
- Interactive robots
- Sound boxes
- Educational projects
🛠️ Repair and integration
- Replacement for small speakers
- Portable radios
- Intercoms
- Sound toys
- Communications equipment
- Small loudspeaker enclosures
- Voice announcement systems
💡 Tips for better sound
- Install the speaker in a small acoustic enclosure.
- Secure it properly to prevent unwanted vibration.
- Face the diaphragm toward an opening or grille.
- Avoid exceeding 3 W during normal operation.
- Reduce the volume immediately if the sound becomes distorted.
- Add a grille to protect the diaphragm.
⚠️ Precautions
- Never connect the speaker directly to 5 V or 12 V.
- Do not drive it directly from an Arduino or ESP32 pin.
- Use an amplifier compatible with an 8 Ω impedance.
- Avoid touching or pressing the diaphragm.
- Protect the speaker from water, dust and metal objects.
- Switch off power before changing the wiring.
Keywords: speaker, loudspeaker.
