4ohm 40mm Diameter 3W Full-Range Audio Speaker

Prototyping and Engineering Tips from Robogears

• Enclosure is Essential: CRITICAL: A speaker without a box (baffle) will sound thin and "tinny" because the sound waves from the back of the cone cancel out the waves from the front (phase cancellation). For the best bass response, mount this speaker in a sealed or ported enclosure with a volume of approximately 0.2 to 0.5 liters.

• Amplifier Matching: This speaker is a perfect match for the PAM8403 (3W+3W) or PAM8302 (single channel) amplifier modules. Ensure your amplifier gain is not set so high that it "clips," as continuous clipping can overheat the small voice coil and cause permanent distortion.

• Polarity Matters: Always check the $(+)$ and $(-)$ markings on the solder tabs. If you are using two speakers for stereo sound and one is wired backward, the bass will disappear because the two speakers will be "pushing" and "pulling" against each other (out of phase).

• Soldering Caution: Use a fine-tip soldering iron and be quick when attaching wires to the tabs. Excessive heat can melt the plastic housing or damage the delicate "tinsel leads" that connect the tabs to the moving voice coil.

• Preventing Rattles: When mounting in a plastic or wooden box, use a thin gasket of foam tape or hot glue around the rim. This prevents air leaks and "buzzing" noises when the speaker plays at high volumes.

Package Includes

• 1 x 4Ω 40mm Diameter 3W Full-Range Audio Speaker

Disclaimer: Do not exceed the 3W power rating for extended periods as it may cause the voice coil to burn out. Keep the speaker away from metal shavings or iron dust, which can be sucked into the magnetic gap and cause scratchy audio. Avoid pushing the center dust cap or the cone with your fingers, as dents can affect the acoustic symmetry.