Sundown SML-Series 8″ D4 Ultra-Thin Subwoofer
400 W RMS ultra-shallow 8-inch dual 4-ohm subwoofer
$199.99
Overview
The Sundown SML-8 D4 is an ultra-shallow 8-inch subwoofer rated 400 W RMS / 800 W peak on dual 4-ohm voice coils with 14 mm Xmax. Mounting depth is about 3.9 inches. A black aluminum 2.25-inch voice coil former, vented pole and gap, dual-magnet motor, and bolt-through construction target deep bass under or behind seats in small sealed boxes.
Product details
Thinner than SLD
SML is about an inch shallower than Sundown’s SLD series while keeping strong excursion for limited-depth installs.

Power and coils
Rated 400 W RMS / 800 W peak with dual 2-ohm or dual 4-ohm coils. This listing is D4.

Enclosure guidance
Sealed about 0.25–0.35 cu ft. Ported is not recommended on the manufacturer page.
Key features
- 8-inch SML thin subwoofer
- 400 W RMS / 800 W peak
- Dual 4-ohm voice coils (D4)
- 14 mm Xmax
- Mounting depth about 3.9"
- Black aluminum 2.25" voice coil former
- Vented pole-piece and magnetic gap
- Bolt-through motor design
- Stitched Mini-XL tinsel leads
Specifications
| Brand | Sundown |
|---|---|
| Model | SML-8 D4 |
| SKU | SML8D4 |
| Product type | Thin subwoofer |
| Size | 8 inch |
| Voice coils | Dual 4 ohm |
| RMS power | 400 W |
| Peak power | 800 W |
| Xmax | 14 mm |
| Mounting depth | 3.9" |
| Sealed volume | 0.25–0.35 cu ft |
| Size | 8 inch |
Important notes
- Requires a compatible amplifier and small sealed enclosure (sold separately)
- Ported enclosures not recommended for this model
- Check under-seat / behind-seat clearance including excursion
- Professional installation recommended
What's in the box
- Sundown SML-8 D4 subwoofer
- Mounting hardware as packaged



