4 inch SubWoofer 4ohms 20Watts

Specification	Details
Speaker Size	4 Inches (100mm)
Impedance	4 Ohms (Ω)
Power Rating	20 Watts (RMS)
Brand	Moonvoice
Magnet Type	Heavy-Duty Ferrite
Frequency Range	60Hz - 5kHz (Approx.)

Price

₹ 161.02 ~~₹ 249.00~~

(Tax included)

Barcode: 60455164

Product Description

The 4" Moonvoice Subwoofer is a high-performance low-frequency driver designed to deliver deep, punchy bass in a compact form factor. Featuring a robust 4-ohm voice coil, this subwoofer is engineered to draw maximum power from 12V or 24V Class-D amplifiers, making it the perfect heart for DIY Bluetooth speakers, desktop 2.1 audio systems, or small automotive audio upgrades. The Moonvoice series is known for its durable rubber surround and stiffened cone, which allow for high-excursion movements without distortion. This ensures that even at high volumes, the low-end frequencies remain tight and well-defined, providing a rich cinematic or musical experience.

Key Features

High-Excursion Design: The flexible rubber surround allows the cone to move significantly, pushing more air to create deeper bass than standard full-range speakers.
Reinforced Paper/Composite Cone: Stiffened to resist "cone breakup" during heavy low-frequency pulses, maintaining acoustic integrity.
Vented Magnet Pole: Many Moonvoice models feature a vented back to allow airflow around the voice coil, preventing overheating during long playback sessions.
4-Ohm High Efficiency: Optimized for modern digital amplifier boards (like the TPA3116D2), allowing for higher volume levels at lower input voltages.
Wide Mounting Flange: Features pre-drilled holes for secure fastening into wooden or 3D-printed enclosures.

Technical Details

Resonant Frequency ($F_s$): ~65Hz.
Sensitivity: ~86dB.
Mounting Depth: ~50mm to 60mm.

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.