# 40mm 3W speaker

> Compact 40 mm speaker, height 20 mm, rated power 3 W, impedance 4 Ω, sensitivity 83 dB/W, frequency response 0.20-20 kHz, THD ≤ 5%. Paper diaphragm, PU surround, black cap, permanent magnet, moving coil. Full range playback, suitable for mini portable speakers, compact stereo systems or DIY projects. Connects to an amplifier with output up to 3 W at 4 Ω.

- Page: https://sigmanortec.ro/en/40mm-3w-speaker
- Price: 7.50 RON
- Availability: In stock; 1-2 zile
- Reference: 33072 · EAN: 5940543217075
- Category: Mechatronics and IoT > Sensors and Modules > Audio and Sound > Speakers and Microphones
- Specifications: Power: 0 - 20W
- Package (shipping data): 0.015 kg
- Updated: 2026-10-06
- Shop: [Sigmanortec.ro](https://sigmanortec.ro/en/llms.txt)
- Prices: RON, VAT included; prices and stock as of 2026-10-22 04:14 (Europe/Bucharest)

## Description

Compact 40 mm speaker, ideal for portable mini speakers, small stereo systems and DIY projects, offers clear full range playback at 3W power. It has 4 Ohm impedance and 83 dB sensitivity for good volume from compact amplifiers, paper diaphragm for natural sound, PU edge and permanent magnet for stable response and reliability.
Compact speaker, with a diameter of 40 mm and a height of 20 mm, suitable for use in portable mini speakers, compact stereo systems or DIY projects, the speaker ensuring good sound reproduction, with a maximum power of 3W.
The construction features a PU (polyurethane) rim and black cap, along with a paper diaphragm and permanent magnet.
Specifications:
Dimensions: Ø 40 mm, height 20 mm
Rated power: 3 W
Impedance: 4 Ω
Frequency response: 0.20 – 20 kHz
Sensitivity: 83 dB/W
Signal to noise ratio: 83 ± 3 dB
Total harmonic distortion (TMD): ≤ 5%
Shape: Round
Diaphragm material: Paper
Case composition: PU edge, black cover
Magnetic type: Permanent magnet (moving coil)
Acoustic characteristics: Full range
Use:
It is mounted in a compatible, sealed acoustic enclosure for optimal performance.
Connects to an amplifier with an output of up to 3W at 4Ω, respecting the polarity marked on the connector (positive is usually marked with + or a Red marker).