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Sundown Audio SD-4 8" D2 Neo Shallow Mount Subwoofer | 400W RMS

Brand : Sundown Audio

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MSRP: $430.99
$318.99
(You save $112.00 )
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SundownAudio-SD-4-8D2-Subwoofer

Sundown Audio SD-4 8" D2 Neo Shallow Mount Subwoofer | 400W RMS

The Sundown Audio SD-4 8" D2 Neo Shallow Mount Subwoofer is part of the latest SD v.4 Neo Series, built as the next evolution of the legendary SD-3. Designed for today’s sealed box applications where depth is limited, the SD-4 combines compact mounting depth, rugged construction, and world-class sound quality. With 400 watts RMS power handling, it’s the perfect shallow-mount subwoofer for daily drivers and enthusiasts looking for big bass in small enclosures.


Shallow Design – Maximum Performance

Unlike many “ultra-shallow” subs, the SD-4 prioritizes both sound quality and durability while still fitting tight spaces. Sundown eliminated the pole vent, allowing the motor to mount completely flush against the enclosure back wall. Combined with the all-new computer-optimized “W” foam surround, the SD-4 reduces required clearance by nearly 2 inches compared to most shallow subs, making it one of the most space-efficient designs available.


Advanced Cooling & Neo Motor Technology

  • Lightweight Neodymium Motor – Reduces angled depth requirements and overall weight compared to ferrite motors.

  • Side-Firing Gap Venting & OD Pole Channels – Provides efficient airflow for superior cooling.

  • Shorting Ring & Aluminum Faraday Ring – Smooths frequency response, lowers distortion, and improves linearity.


Engineered for Sound Quality

The SD-4 uses an under-hung motor topology, meaning the voice coil stays fully within the magnetic gap during excursion. This ensures an extremely flat BL curve and ultra-low distortion. With 14.5mm of linear excursion (one-way), the SD-4 delivers deep, accurate bass with superb sound quality in compact sealed enclosures.


Built to Last

  • RMS Power Handling: 400W RMS

  • Voice Coil Configuration: Dual 2 Ohm (D2)

  • Voice Coil: 2” 8-layer high-temp copper coil on black aluminum former

  • Surround: Computer-optimized foam “W” surround for reduced clearance and durability

  • Frame: Patented high-strength cast aluminum frame (US Patent D691595)

  • Durability: Stitched-on tinsel leads and spring-loaded terminals for reliability under high excursion


Key Features at a Glance

  • 400W RMS Power Handling

  • Dual 2 Ohm Voice Coil (D2)

  • 14.5mm Xmax one-way by 70% BL

  • Lightweight Neodymium Motor for reduced mounting depth

  • Under-hung low distortion motor design

  • Solid pole piece with chamfered edges

  • Black aluminum coil former for superior heat dissipation

  • Large aluminum Faraday ring for smooth response

  • Optimized for small sealed enclosures


Why Choose the Sundown SD-4 8" D2?

The Sundown Audio SD-4 8" D2 Neo Shallow Mount Subwoofer is the ideal choice for car audio enthusiasts who need a space-saving subwoofer with serious performance. It’s shallow enough to fit into modern depth-restricted enclosures but rugged and powerful enough to deliver the deep, accurate bass Sundown is famous for.

Perfect for daily drivers, SQ setups, or tight-sealed applications, the SD-4 8" D2 is proof that small doesn’t mean weak — it means efficient, powerful, and precise.

 

SPECIFICATIONS

T/S SPECS SD-4 8″ D2
RE (Ohms) 4.2018
FS (Hz) 35.6841
VAS (L) 12.1640
Qes 0.5783
Qms 5.7988
Qts 0.5259
Le (mH) 4.4242
BL (NA) 13.1700
Mms (Grams) 106.4747
Cms (uM/N) 186.8295
Sens (dB @ 1w/1m) 81.5509
 

ENCLOSURE SPECIFICATIONS

Sealed Enclosure 0.33-0.5 cu ft
Ported Enclosure Not Recommended
Recommended Tuning N/A
Recommended Port Area N/A
Displacement 0.07 cu ft
Depth 4.6"
Outside Diameter 8.70"
Cut-Out 7.30"
Physical Dimensions Download