4 inch SubWoofer 4ohms 20Watts

Prototyping and Engineering Tips from Robogears

• Enclosure Type is Critical: CRITICAL: A subwoofer will not produce bass if it is "Free Air" (not in a box). For this 4-inch driver, we recommend a Ported (Vented) Enclosure for maximum "boom" or a Sealed Enclosure for more accurate, "tight" bass. Use an online enclosure calculator to determine the internal volume (Liters) based on the speaker size.

• The "Air Leak" Warning: Bass performance depends on pressure. When mounting the subwoofer, use a foam gasket or silicone sealant between the speaker rim and the box. Even a tiny air leak around the screw holes will drastically reduce the bass output.

• Amplifier Matching: To drive this 20W subwoofer properly, use an amplifier rated for at least 30W to 50W. Having a slightly more powerful amplifier (headroom) prevents "clipping," which is the #1 cause of burnt voice coils in subwoofers.

• Low Pass Filter (LPF): Since this is a subwoofer, it should only play low frequencies. Use a Crossover or an amplifier with a built-in LPF set to around 150Hz. If you let high frequencies (vocals) play through the subwoofer, it will sound muddy and may overheat the coil.

• Wiring Gauge: For 20W of power, standard thin jumper wires are insufficient. Use 18 AWG to 16 AWG speaker wire to ensure the power reaches the driver without resistance-related losses.

Package Includes

• 1 x 4" Subwoofer 4 Ohms 20 Watts (Moonvoice)

Disclaimer: Do not exceed the 20W RMS power rating for extended periods. Ensure the speaker is securely mounted before testing, as the vibration at high volumes can cause an unmounted speaker to "walk" off a table. Avoid touching the center dust cap or the cone while the speaker is active to prevent damage to the suspension.